Growing the major food plants of Papua New Guinea

Growing the major
food plants
of
Papua New Guinea
A description of the crops,
how and where they are grown,
and some of the problems
with their production.
Bruce R French
1
What is this book about?
Papua New Guinea has a beautiful range of plants that can be used for food. It is still true
that many of these have not been written about properly. Many of the highly nutritious edible
greens are simply called “kumu” and in many places are not highly regarded. Often these plants are
grown throughout the tropics and are of worldwide importance. But because they lack a name in
English they also often don't have one in Tok Pisin and few books discuss them.
This book is going to talk about growing food in Papua New Guinea. Not everybody in the
country grows and eats the same foods. Neither do they grow them or use them in the same way.
Many of the more traditional food plants have lots of different names in different Tok Ples
languages. It is hoped the drawings and descriptions will be enough to help you to work out the
plant that is being described. Scientists give every plant a name in the Latin language. This is
included so that we can know exactly which plant is being talked about. This name stays the same
whatever country or whatever language is being used. So these names look hard but they are very
useful. Sometimes Tok Pisin or Tok Ples names are included.
Most of the food plants people grow and use are very good food plants. They are something
about which people should be proud. They are something about which we all should take a special
interest.
This book is dedicated to those who still seek to fulfil what
God asked in Genesis 2:15.
"The LORD God took the man
and put him in the Garden of Eden
to work it and take care of it."
INDEX for GROWING Food Plants
Main staple foods
Bananas
Cassava
Potatoes
Sago
Solomon's sago
Sweet potato
Taro family
Winged bean
Yams
Other root crops.
Page
Chinese taro
Elephant foot yam
Giant taro
Swamp taro
Taro
Greater yam
Lesser yam
Potato yam
Five leaflet yam
Polynesian arrowroot
Queensland arrowroot
Ipomoea macrantha
7
20
26
31
40
42
54
59
61
63
65
74
82
84
88
89
96
98
99
Edible greens
101
Aibika
Amaranth
Blackberried nightshade
Ferns
Kangkong
Kalava (Ormocarpum)
Rungia
Dicliptera papuana
Valanguar
Tu-lip
Watercress
Rorippa
Water dropwort (Oenanthe)
Waterleaf
104
110
118
121
122
123
124
124
127
128
129
131
132
134
135
137
142
143
145
147
Vegetables
149
Bamboo - small and large
Beans
150
153
153
154
Fig leaves
Climbing swamp fern
Tree ferns
Diplazium
Kumugras
Waterfern
Ficus pungens
Ficus copiosa
Common bean
Long or snake bean
Cowpea
3
Cabbage family
Capsicum
Chilli
Corn
Ginger
Job's tears
Peanut
Pitpits
Lima bean
Lablab bean
Cabbage
Chinese cabbage
Nasturtium schlechteri
Coastal or long pitpit
Highlands or short pitpit
Pumpkin family
Onions
Bottle gourd
Choko
Cucumbers
Pumpkins
Angled loofah
Smooth loofah
Bitter cucumber
Wax gourd
Trichosanthes pulleana
Leeks
Spring onions
155
156
167
168
143
172
174
176
184
186
187
193
196
201
204
206
209
210
211
212
213
214
218
218
Fruit
219
Avocado
Bukubuk
Citrus
Custard apple family
220
223
225
230
233
235
237
239
241
243
245
248
250
252
255
254
253
256
257
260
264
266
268
Bullock's heart
Cherimoya
Soursop
Sweetsop
Five corner
Golden apple
Guava & cherry guava
Indian mulberry
Laulaus (Syzygium spp.)
Malay apple
Rose apple
Surinam cherry
Watery rose apple
Lovilovi family
Mango
Marita
Mon (Dracontomelon)
Mulberry
Mundroi (Corynocarpus)
Myristica
Naranjilla
Tree tomato
270
272
Passionfruits & Granadilla
Pawpaw
Pineapple
Sugarcane
Ton (Pometia pinnata)
Watermelon
274
278
283
286
295
297
Nuts
299
Aila
Breadfruit family
Okari, talis, Java almond
Pao nuts
301
304
305
309
311
313
315
317
323
327
329
330
337
340
342
349
Index
Scientific names
Common name
354
357
Breadfruit
Jackfruit
Pakal
Candlenut
Castanopsis chestnuts
Coconut
Galip nuts
Finschia nuts
Karuka family
Karuka
Wild karuka
Pandanus antaresensis
5
Main staple foods
Sweet potato
Lesser yam
Taro
Banana
Cassava
Greater yam
Elephant foot yam
Chinese taro
Banana
Scientific name:
Musa sp. (A&/or B genome)
Bananas
Most areas of Papua New Guinea have bananas. Some people have them as their main
staple food while in other areas they are just a snack food. There is a very large amount of variation
within the banana varieties in Papua New Guinea. It is important to understand something about
these types of bananas.
Within some of these groups, Papua New Guinea has more varieties than any other country
in the world. Within the banana group of plants there are several wild ones. In Bougainville the
rainforest has many wild inedible bananas. But this article is about the main group of edible kinds
of bananas.
The banana story
Although this story of the history of bananas is a little complicated it is important because it
is most likely that all these kinds of bananas probably originally developed in Papua New Guinea.
It is also important for banana growers to recognise some of the important differences between the
groups.
Originally there were small traditional bananas like some of the edible kinds but the fruit
were full of seeds. One of these became a parent of present bananas and by scientists is represented
by AA meaning both its sets of chromosomes came from an original plant (Musa acuminata [Syn.
Musa banksi]). This plant occurs as a wild seeded plant in many areas along the north coast of
mainland Papua New Guinea. This plant when it is without seeds gives an important group of local
edible bananas called diploids. Varieties in the Gazelle with names like kekiau, gulum, pitu, gorop
and katual belong to this group. But another wild seeded parent is also another parent of some of
the present bananas. This plant is called “BB” by scientists, because it has two sets of chromosomes
from an original plant (Musa balbisiana). This plant occurs in the Gazelle Peninsula and is called
Okaoko. A similar banana plant in the Gazelle Peninsula is called Auko and is an edible cultivated
banana without seeds.
The wild seeded AA banana
The wild seeded BB banana
As well as both the wild seeded parents of bananas occurring in Papua New Guinea, they also occur
as non-seeded edible bananas.
7
So the start of the banana story is that these two wild seeded parents have crossed.
AA x
BB
AB
A banana fruit full of seeds
But another thing can occur with bananas and this is where they develop more than two sets
of chromosomes (the threads that contain the messages that control breeds and breeding). So there
can also be plants represented as:
AAA
AAB
ABB
AAAA
AABB
ABBB
Occasionally plants can cross with some of the other wild bananas in Papua New Guinea
(Musa schizocarpa) and give ones such as AS which is called Kalakala variety in Morobe district or
ABBS.
So the picture of the main group of bananas in Papua New Guinea starts to look something
like this: (Using Tolai variety names)
Diploids
Triploids
ABB
eg Mami, kekiau, gulum, gorop etc.
eg Auko.
eg Siaina, (Cavendish), marau,
eg avundumong, maramba, akambia,
(Some very large fruited kinds within this group are
called “Horn Plantains” and “French Plantains” in other
countries. These kinds can be seen in Sepik areas in
PNG.)
eg Jawa, Kalapua, Akambia
AAAB
AABB
ABBB
eg Atan
eg Kalamasol (North Solomons)
Jawa2
AS
eg Kalakala (Morobe district)
AA
BB
AAA
AAB
Tetraploids
Others
Diploid banana
Colouring of AB group stems
Colouring of A group stems
B group bracts
Colouring of B group stems
Bunch and bracts A group
9
This drawing is of a diploid (kekiau) banana. With these the leaves point upwards and they
are a smaller plant with less suckers.
Drawing by Celia Bridle
These traditional diploid bananas usually have only a few suckers and smaller bunches. They grow
quickly but need to relocated and transplanted on a regular basis. They cannot tolerate poor soils
and do not keep growing as bunches near houses nut are put in new gardens.
The next drawing is of a triploid banana. The leaves hang over and the plant is more robust
with more suckers.
Drawing by Celia Bridle
There are a range of triploid bananas. They tend to be large and can have chromosomes from both
A and B parents. Some of these varieties produced large clumps of bananas and suckers. They can
often grow for a long time near houses.
11
A triploid banana
or one with 3 sets
of chromosome
A diploid banana or
one with 2 sets of
chromosomes
A seeded banana
A tetraploid banana
or one with 3 sets of
chromosomes
Seedling bananas grown
from seed
Why is understanding the banana story important?
With bananas it is important to put the right kind of banana in the right place. The different
groups of bananas have some things in common. Often "A" means the banana can't stand shade,
cannot tolerate drought, needs fertile soil, and gets certain diseases. Similarly "B" means these
plants can grow with more shade in drier soils and with lower soil fertility. As well, diploids (2 sets
of chromosomes) are mostly smaller plants with fewer fruit and they produce less suckers. They
need to be replanted after each crop of bananas. Some triploids such as ABB (Java) can often grow
for many years in the one place and with poor soil. Some tetraploids such as (ABBB) are extremely
large plants.
An understanding of these types can be seen in the way some Tolais lay out their gardens.
AA types are used as temporary shade for cacao.
AAA types are put in fertile areas near creeks.
AAB and ABB types are put around houses and along tracks leading to water etc where they
will be left to grow for many years.
Growing bananas
After choosing the type of banana it is important to grow it well.
A healthy sucker needs to be cleaned to be sure that insects or nematodes or fungal diseases
are not carried from one garden to the new garden. Choose a straight sword-like sucker not one that
has leaves hanging out wide as soon as it comes through the ground.
The sucker needs to be put in freshly cleared ground where the soil is fertile, or the soil
needs to be built up by putting compost and plant material in the planting hole. A hole 30 cm x 30
cm is suitable for most varieties.
The spacing of the plant will depend on variety and whether it is being intercropped with
other plants. Diploid plants can be 1.5 m apart and larger kinds need to be 2 m or more apart.
Thought needs to be given to whether it is a kind that will be replanted within a year or left to grow
as a large clump for several years.
13
Soils must be well drained and most bananas require a fairly fertile soil. For larger bunches
of fruit, some suckers need to be removed on the kinds that sucker freely.
Banana insect pests
Apiraculus cornutus (Pascoe)
Cosmopolites sordidus (Germar)
Bactrocera bryoniae (Try)
Bactrocera musae (Try)
Dermolepida nigrum (Nonf)
Diacrisia papuana Roths
Eumossula gracilis
Heliothis armiger Hubner
Lema papuana Jac.
Locusta migratoria (Linnaeus)
Myospila argentata Walker
Nacoleia octasema (Meyrick)
Opagona sp.
Oribius cruciatus Fst.
Oribius inimicus Mshl
Oryctes rhinoceros (L)
Othreis fullonica (Cl)
Papuana huebneri Fairm.
Papuana laevipennis Arrow
Papuana japenensis Arrow
Papuana semistriata
Papuana woodlarkiana (Montr.)
Pentalonia nigronervosa Coq
Scapanes australis australis Boisd.
Scapanes australis grossepunctatus
Scopelodes nitens B.Bak
Segestidea defoliata Uvarov
Segestidea novaeguineae F.Willemse
Taenaris dimona Hew
Taenaris myops kirschi Stgr.
Horned weevil
Banana weevil
Fruit fly
Banana fruit fly
Chafer beetle
Coconut treehopper
Corn earworm
Migratory locust
Banana scab moth
Shot hole weevil
Rhinoceros beetle
Taro beetle
Taro beetle
Taro beetle
Taro beetle
Taro beetle
Banana aphid
Australian Rhinoceros beetle
New Guinea rhinoceros beetle
Banana butterfly
Banana insect pests
Banana aphid (Pentalonia nigronervosa)
This small sap-sucking aphid is potentially
very important because it can spread virus disease
around. These virus diseases have not been confirmed
as present in Papua New Guinea yet.
Banana fruit fly (Bactrocera musae)
Ripe fruit can easily be attacked and spoilt by
this (and other) fruit flies. Fruit need to be harvested
and stored carefully.
Curculionidae
Curculionidae
Tephritidae
Tephritidae
Scarabaeidae
Arctiidae
Tettigoniidae
Noctuidae
Chrysomelidae
Acrididae
Muscidae
Pyralidae
Hieroxestidae
Curculionidae
Curculionidae
Scarabaeidae
Noctuidae
Scarabaeidae
Scarabaeidae
Scarabaeidae
Scarabaeidae
Scarabaeidae
Aphididae
Scarabaeidae
Scarabaeidae
Limocodidae
Tettigoniidae
Tettigoniidae
Amathusiidae
Amathusiidae
(COL)
(COL)
(DIPT)
(DIPT)
(COL)
(LEP)
(ORTH)
(LEP)
(COL)
(ORTH)
(DIPT)
(LEP)
(LEP.)
(COL.)
(COL.)
(COL.)
(LEP.)
(COL.)
(COL.)
(COL.)
(COL.)
(COL.)
(HOM.)
(COL.)
(COL.)
(LEP.)
(ORTH.)
(ORTH.)
(LEP.)
(LEP.)
Banana rust thrips (Chaetanothrips orchidii & C. signipennis)
These small sucking insects cause rusty red
discolouration between the fingers of the fruit. The skin
becomes rough and can crack. It only spoils the
appearance of the fruit. In some countries putting bags
over the fruit is used. Traditional wrapping of fruit
bunches may help.
Banana scab moth (Nacoleia octasema)
This very small moth hides under dead leaves
during the day lays eggs on the flowers and the
caterpillars. It badly damages the fruit in New Britain.
Removing dead banana leaves near the trunk, cutting off
the male flower and using varieties with widely spaced
fingers reduces risk of damage a little.
Banana weevil (Cosmopolites sordidus)
This long nosed weevil only occurs in some coastal
areas but can damage banana plants by burrowing into the
stems and causing them to fall over. "B" group bananas
get less damaged. It is also important to use clean suckers
for planting.
Banana butterfly (Taenaris myops kirschi)
The larvae of this moth can group together and eat
the leaves of bananas causing extensive damage. The
caterpillars are 5 cm long, greyish yellow with three lines
along the side and 2 bunches of hairs on the back of each
segment.
Rhinoceros beetles (Scapanes australis) & (Oryctes rhinoceros)
These beetles can burrow into the false stem of
bananas causing plants to fall over and to put their
bunches out the side of the stem. The beetles breed in
rubbish heaps so removing these from gardens helps
control. Also stripping off old leaves to form smooth
banana stems makes it harder for the beetles to find
somewhere to start digging into the stem.
Taro beetles (Papuana spp.)
These small brown and black beetles can dig very
efficiently and damage the underground parts of banana
plants as well as other root crops. They are hard to
control.
15
Bananas scab moth damage
Banana Black cross
Diamond leaf spot
Black spot
Cucumber mosaic virus
Banana rust
Black Sigatoka
Banana diseases
Armillaria corm rot
Leaf spot
Anthracnose fruit
Diamond leaf spot
Black spot
Leaf spot
Leaf spot
Black leaf streak
Sigatoka leaf spot
Black cross
Freckle
Speckle
Banana rust
Root rot
Stem end rot fruit
Algal leaf spot
Infectious chlorosis
Root knot
Burrowing nematode
Nematode
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungi
and
Fungus
Alga
Virus
Nematode
Nematode
Nematode
Bacterial corm rot
Stalk rot
Bacteria
Bacteria
Armillaria mellea
Cladosporium musae
Colletotrichum musae
Cordana musae
Deightoniella torulosa
Haplobasidium musae
Phyllosticta sp.
Mycosphaerella fijiensis
Mycosphaerella musicola
Phyllachora musicola
Guignardia musae
Ramichloridium musae
Uredo musae
Pythium splendens
Pythium vexans etc
Botryodiplodia theobromae
Cephaleuros virescens
Cucumber mosaic virus
Meloidogyne incognita
Radopholus similis
Helicotylenchus multicinctus
Pratylenchus sp.
Rotylenchus sp.
Erwinia chrysanthemi
Erwinia carotovora carotovora
Banana diseases
Sigatoka leaf spot (Mycosphaerella musicola)
A yellowish green speck on the leaf turns into a
streak and turns brown. The brown centre has a
yellow ring around it. It is caused by a fungus and
gets worse on "A" type bananas and in wet weather.
Leaves can die off early.
Black Sigatoka (Mycosphaerella fijiensis)
This fungus leaf spot similar to Sigatoka has
caused severe problems in banana plants many other
countries.
ABB clones seem to get this disease less.
Black cross (Phyllachora musicola)
A fungus grows on the leaf in the shape of a
black cross. It seems to cause little damage but may let
other fungal diseases get started.
17
Diamond leaf spot (Cordana musae)
The spots are yellow and oval shaped. Often
rings can be seen inside the spots. The edge of the leaf
has an uneven bright zigzag yellow band. The disease
is caused by a fungus. The fungus normally starts its
attack after other fungi have damaged the leaf.
Banana rust (Uromyces musae)
This fungus which causing brown marks which
look like rust only occurs occasionally on some
varieties eg Pitu. It does not appear to be a very serious
problem.
Freckle (Guignardia musae)
Small black speckled stripes develop on the
leaves. They are mostly on the upper side of old leaves
and go from the midrib towards the leaf edge. ABB
bananas seem to get it most.
Speckle (Veronaea musae)
Soft grey covered spots develop on the lower
surfaces of old leaves in humid areas. It tends to be
worse on AAA type bananas.
Anthracnose of bananas
The fungus causes black spots on ripening fruit. The
spots get larger and cover the whole fruit. They get
worse in wet weather.
Armillaria root rot
The leaves turn yellow and die from the base upwards.
The plant can be pushed over or breaks off at ground
level. The corm becomes brown and dead and has
white threads growing through it. It occurs above
1,000m altitude in cooler areas.
Banana pests
Burrowing nematode (Radopholus similis)
This very small worm burrows into the roots of
bananas in lowland areas and causes plants to reduce
in vigour. Because of this it is necessary to move
plants each couple of years. It is also important to
clean the suckers and roots to avoid taking the
nematodes to new gardens.
Bananas as food
The large number of varieties of bananas in Papua New Guinea means there are kinds of
bananas for many different purposes.
Some are sweet and soft and eaten fresh as a snack and baby food eg Cavendish.
Others are dry and starchy and need to be moistened in a soup.
Some eg kekiau are quickly roasted in garden fires and eaten as snacks.
Others are boiled or baked and eaten as a main starchy staple eg Kalapua
19
Cassava
Tok Pisin: Tapiok
Scientific name: Manihot esculenta
The cassava plant
Cassava has been introduced to Papua New Guinea and has become widespread because it is
easily grown and requires little weeding, and will grow on a range of soils and in a range of
climates. It also suffers little from pest and disease damage at present in Papua New Guinea.
Cassava has a long woody stalk with leaves that are divided like the fingers of your hand.
The width and shape of these leaflets varies between the different varieties. The leaf is on a long
leaf stalk that can be coloured red or green. Where the leaf falls off there is a raised leaf scar on the
stem.
Below the ground several long fattened roots form. These continue to increase in size and
store starch as the plant matures.
Drawing by Celia Bridle
Planting cassava
Cassava is planted from sections of the stalk. Sections about 15-20 cm long of the more
mature woody stem are cut and stuck into the ground. They can be completely buried or put at
almost any angle and it affects the growth little. Soon roots form and leaves start to sprout from the
stalk.
It is not necessary to dig a hole to plant cassava and on many soils where the soil is loose it
can be planted without digging the soil first. Cassava does not suit waterlogged soils and preferably
they should not be too shallow or stony.
Cassava grows best in the tropical lowlands but will grow up to about 1800 metres above
sea level. Once the cassava plant is established it can withstand fairly long periods of drought so is
useful to have in seasonally dry areas such as the Markhum Valley and the Central Province.
Cassava can be planted at any time of the year but to get started it needs moisture so is often
planted near the beginning of the wet season. Because cassava can still grow satisfactorily in poorer
soils it is often put last in a rotation after others crops have already been grown on the piece of land.
Cassava takes about 10 to 12 months to produce mature tubers in the lowlands although
some varieties produce a smaller yield earlier. The plants can be left growing and the tubers stored
in the soil for considerable time. Once the tubers have been dug they do not keep for more than a
few days.
21
Cassava as food
Cassava, like a number of other tropical crops contains large amounts of a poisonous
chemical called hydrogen cyanide. It is because of this poison that commonly in coastal areas wild
unused cassava plants can be seen growing along roadsides and riverbanks. These kinds are too
bitter to use. All cassava contains this chemical but some kinds contain larger amounts. It is
because of this chemical that it is important to cook cassava well. The chemical gets destroyed on
strong heating.
Cassava tubers are a starchy energy food but are lower in protein than some other root crops.
The leaves however are very high in protein so the young leaves are good quality food providing
they are well cooked.
Cassava tubers can just be baked in the ashes or boiled in water. Often people grate the
tuber and make cassava cakes mixed with some coconut milk.
These pale yellow young leaves
are a deficiency in cassava that is
growing on coral soils with a
high pH
Thankfully this serious virus disease is
not yet in PNG but occurs in Africa
Insect pests
Acalolepta holotephra
Cerambycidae (COL)
Amblypelta spp.
Apirocalus cornutus
Aulacophora spp.
Brysica exigua
Ectropis bhurmitra
Ferrisia virgata
Hypotactus ruralis
Leptoglossus australis
Oribius cruciatus
Protaetia papuana
Pseudaulacaspis pentagona
Parasaissetia nigra
Tetranychus sp.
Tiracola plagiata
Coreidae (HEM)
Curculionidae (COL)
Chrysomelidae (COL)
Pentatomidae (HEM)
Geometridae (LEP)
Pseudococcidae (HEM)
Curculionidae (COL)
Coreidae (HEM)
Curculionidae (COL)
Scarabaeidae (COL)
Diaspididae (HEM)
Coccidae (HEM)
Tetranychidae (ACAR)
Noctuidae (LEP)
Insects
Tip wilt bugs (Amblypelta spp.)
The adults are about 20 mm long. They are a greenish
brown with smoky wings. The colour varies with species.
They fly short distances in warm times of day. In cassava
they have been reported as killing the growing tips. This
is particularly for Amblypelta lutescens papuensis and it
occurs at low altitudes on the south side of PNG. These
insects live in the bush and can be worse near there. They
can be controlled by Kukuram ants.
Cacao looper (Ectropis bhurmitra)
The larvae of this moth move by forming a loop. They
can build up into large numbers given the right conditions.
They damage young leaves by eating them. Thay also
damage other plants. They have other insects that control
them naturally.
Black leaf-footed bug (Leptoglossus australis)
This bug is about 20 mm long and smoky black in colour.
The body has several orange to red spots. The hind legs
are long and flattened and toothed along the edge. The
antennae have black and pale orange zones along their
length. They damage a number of plants. The insect
occurs in most districts of PNG at most temperatures and
localities, wet and dry, grassland and forest up to 1750 m
altitude. It tends to be common but not serious. Control is
not normally necessary.
Shot hole weevil (Oribius cruciatus)
These are small hard long nosed weevils that are common
on many plants. They chew small irregular holes. They
get worse in weedy gardens. The weevils can be hand
23
Boring into Ficus and cassava
stems
Spotting bugs or tip wilt bugs
Horned weevil
Pumpkin beetles
Cacao looper
Mealybug
Weevil
Passionvine bug
Shot hole weevil
Cassava scale
Nigra scale
Red spider mite
Banana fruit caterpillar
picked into a tin of water with a layer of kerosene on the
surface.
Diseases of cassava
Brown leaf spot
Leaf spot
Leaf spot
Blight leaf spot or (Tip die back)
Pink disease
Associated with root rot
Collar rot
Root rot
Fungus
Fungus
Fungus
Fungus
and
Fungus
Fungus
Fungus
Fungus
and
and
Cercosporidium henningsii
Cercospora vicosae
Phyllosticta sp.
Colletotrichum capsici
Glomerella cingulata
Corticium salmonicolor
Dictyosporium toriloides
Fusarium sp.
Helicobasidium purpureum
Proboscispora manihotis
Rigidoporus lignosus
Storage rots
At present in Papua New Guinea diseases do not cause a major problem with cassava growing.
There are some serious diseases in other countries that make cassava growing difficult so it is
important that people do not bring cassava cuttings into Papua New Guinea without careful control
by Agricultural and quarantine specialists.
Leaf spots
Leaf spots on cassava can be caused by several
different fungi and therefore are given different
names.
Brown leaf spot
This disease is caused by a fungus called
Cercosporidium henningsii, but also called
Mycosphaerella henningsii. This depends on
whether the sexual or the asexual life cycle of the
fungus is being described. Brown spots occur on the
older leaves of cassava. These start as small yellow
spots and become brown and angular. Often the
spots are darker around the edge then form a yellow
ring. The disease gets worse in warm wet weather
and when plants are over 5 months old. When this
disease occurs leaves tend to fall off earlier so less
food is stored in the roots. The amount of disease
can be reduced by using wider plant spacing,
removing old infected plants and using crop
rotations.
Diffuse leaf spot of cassava
This disease is caused by a fungus called
Cercospora vicosae. The spots are large and brown
without definite borders. Each spot can cover one
fifth of the leaflet. Under the leaf, the spots have a
grey centre. It occurs on older leaves and in warm
areas during the wet season. It does not appear to do
a lot of damage and control is probably not
necessary.
Phyllosticta leaf spots
These leaf spots tend to be brown and the centre
of the dead spot falls out leaving a hole in the leaf.
They are due to fungi called Phyllosticta sp. Mostly
they are not a serious problem.
Anthracnose (Also called wither tip and blight
leaf spot)
This disease is caused by a fungus with the
scientific name of Glomerella cingulata. (Also
called Colletotrichum gloeosporoides). This is a
very common fungus and attacks many different
plants. With cassava, the edges of the leaves die and
leaves can develop spots and become twisted.
Normally this disease gets worse where
temperatures are about 25°C and the humidity is
high. It spreads when there are heavy rains. This
disease gets worse where the plants are growing in
soil with low fertility and where plants are crowded
and little air can blow between plants. It gets worse
when plants are growing in shaded places. The
disease gets started more easily where plants are
damaged. Normally the best control of this disease
is to improve the growing conditions.
25
Potatoes
Tok Pisin: Peteta
Scientific name:
Solanum tuberosum
The potato plant
This is a short bushy plant that grows up to about one metre tall. It is branched and has
wings on the stems. The leaves are made up of several leaflets of different size and shape.
Under the ground it produces a cluster of tubers. These tubers have buds or "eyes" around
them and these are grouped more towards one end. New stalks can grow from these buds.
Many kinds of potatoes produce flowers at the top. They are normally white or light blue.
These flowers are replaced by round green berries that contain the seeds. Normally these seeds are
only used for breeding new kinds of potatoes.
Where are potatoes grown?
Potatoes can be grown from about 1200 metres altitude up to at least 2750 metres altitude.
They only start to become important in subsistence above about 2000 metres and over 2400 metres
are becoming the staple food crop. People past Margarima towards Tari, and people in Upper
Mendi towards Tambul grow potatoes as one of their main crops. This also occurs in some areas of
Enga Province. In these areas potatoes and wild karuka can be seen growing together.
Potatoes have a shorter time to maturity than sweet potato especially at the higher altitudes.
Therefore it has advantages as a root crop. Above 2700 metres sweet potato often won't develop
tubers but potatoes grow well. Below 1200 metres potatoes often won't develop tubers. Erave
which is lower than this altitude, is colder than other places at the same altitude so potatoes can still
be grown there.
Potatoes tend to need higher soil fertility than sweet potato. Potatoes will only grow very
poorly in old sweet potato gardens. For good production they need to be planted in newer gardens
cleared in the bush or in places where the soil fertility has been built up.
Growing potatoes
Potatoes are grown by planting a tuber, or a piece of a tuber. This is called a "sett". If you
look at a potato you will see it has several buds or "eyes" around it in a spiral and getting closer
together towards the end. Each of these "eyes" can produce a new shoot and therefore a new plant
but if the whole tuber is planted mostly the buds near the end grow and produce a plant with only a
few shoots. If the potato tuber is cut so that each piece contains an "eye" or bud, each piece can
grow into a new plant.
Some choices about disease need to be made when planting potatoes. If small whole tubers
are planted, it could be that they are small because of virus diseases and these therefore will
produce a poorer crop. But if large tubers are cut, rots can develop more quickly on the cut surface
and as well bacterial rot can be spread between plants on the cutting knife. So choices have to be
made whether to plant small whole tubers or to plant pieces of larger cut tubers. As a grower gets to
know his disease problems he can make this choice wisely.
Potatoes in subsistence should be planted intercropped with other plants and not in rows.
This is because bacterial wilt disease can spread between plants and along rows if potato plants are
close together or touching each other. When plants are widely spaced amongst other plants they do
not get this disease because it cannot blow in the wind but must spread by washing in water or
touching.
Bacterial wilt spreads in sap when tubers are cut
before planting or when plants rub together
27
How do potatoes grow?
Potatoes grow a top first of all, then later they start to develop tubers under the ground. The
tubers normally keep increasing in size as the top matures and also as the top then dries off. So
normally potatoes are left growing until the tops have almost died off, then the potatoes are
harvested.
As potato tubers grow and enlarge, the tubers can come up out of the ground. It is important
to keep the soil mounded up around the potato plant to prevent them being exposed to the sunlight.
This is important, because potato tubers turn green with sunlight, and are then poisonous and so are
no use (except for replanting).
Potatoes suffer seriously from a few diseases.
Potato diseases
Target spot
Collar rot & wilt
Dry rot & wilt
Storage rot
Leaf spot
Leaf spot
Late blight
Powdery scab
Common scab
Black scurf
Black leg
Soft rot
Bacterial wilt
Bacterial wilt
Leaf roll
Interveinal mottling
Mosaic & dying leaves
Root knot
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Bacteria
Bacteria
Bacteria
Bacteria
Virus
Virus
Virus
Nematode
Alternaria solani
Athelia rolfsii
Fusarium oxysporium
Fusarium solani
Leptosphaerulina trifolii
Phyllosticta sp.
Phytophthora infestans
Spongospora subterranea
Streptomyces scabies
Thanatephorus cucumeris
Erwinia carotovora sub sp.atroseptica
Erwinia carotovora sub sp. carotovora
Erwinia chrysanthemi
Pseudomonas solanacearum
Leaf roll virus
Potato virus x
Potato virus y
Meloidogyne javanica
PESTS AND DISEASES
Bacterial wilt
One of the most serious disease damaging
potatoes in Papua New Guinea is a disease called
bacterial wilt. With this disease the leaves and top of
the plant start to wilt and collapse. The whole plant
finally collapses and the tubers rot. So no food is
harvested. If plants that are starting to wilt are quickly
harvested the tubers can be eaten. But they should not
be replanted because the disease bacteria will spread in
the potato. If one of these tubers is cut in half and
then squeezed drops of milky liquid that contain
bacteria can be seen in a ring around the tuber.
Target spot
This disease is easy to see. It is produced by a
fungus. This causes black dead spots to develop on
the leaves. These spots often have a pattern of rings in
them and this is why it is called Target Spot.
Sometimes it is also called Early Blight because the
leaves can die around the edge. When plants get this
disease, the leaves die off early. Tubers are therefore
smaller. It gets worse in wet cool places.
Common scab
On the skin of the tuber small brown spots can
develop near the "breathing pores". These can then
turn into a corky scab. This is due to a fungus. It gets
worse in low fertility soil. It only spoils the
appearance of the tuber.
Potato blight
Spots start to develop on the stems and leaves.
They are not distinct round spots (like target
spot) but irregular dark soft spots. The disease
spreads fastest when temperatures are 18° to
22°C and the humidity is high. It needs
moisture on the leaves for several hours.
Potato insect pests
Aphids these suck sap and spread viruses
Potato aphid
Aphididae (HEM)
Foxglove aphid
Aphididae (HEM)
Green peach aphid
Aphididae (HEM)
Melon aphid
Aphididae (HEM)
Aphididae (HEM)
Aphididae (HEM)
Leaf sucking
Nysius villicus Van
Duzee
Sugarcane bug
Macrosiphum euphorbiae (Thomson)
Aulacorthum solani Kaltenbach
Myzus persicae Sulzer
Aphis gossypii Glover
Acyrthosiphon solani Kaltenbach
Myzus ornatus Laing Common in highlands on
potato
Lygaeidae (HEM)
Reported sucking on potato and sweet
potato. They are inconspicuous greyish
brown bugs 3-4mm long. The damage is
normally unimportant. They normally live
on weeds.
Colobathristidae/Pyrrocoridae Phaenacantha spp. Probably P. australiae.
(HEM)
Sucks sap.
Leaf eating
Leaf eating ladybird
and
Monolepta semiviolacea Fauvel
Henosepilachna signatipennis Boisd.
Henosepilachna haemorrhoea (Biel)
Chrysomelidae (COL.)
29
Small tortoise beetles
Cicadella sp.
Conoderus mucronatus Candeze
Dasychira mendosa Hubn.
Homeoxipha fuscipennis
Idopsis coerulea Faust.
Tuber damaging
Potato tuber moth
Black cutworm
Taro beetles
Apachynus beccarii Dubrony
Foxglove aphid
Henosepilachna haemorrhoea
Dasychira mendosa
Taro beetles
Cassida diomma Boisduval
Cassida papuana Spaeth
Cassida sexguttata Boisduval
Cicadellidae (HEM)
Elateridae (COL)
Lymantriidae (LEP) Leaf eating caterpillar Also known to
damage potato. Larvae small and brightly coloured. The head
and legs are red. A tuft of white hairs occurs on the fourth
segment, and a black one on the fifth. There is a white band
around the body surrounded by a red spot. They are 30-40
mm long. They eat many shrubs and trees. Some now
renamed Psalis.
Gryllidae (ORTH.)
Curculionidae (COL) Causing minor shot hole damage
Phthorimaea operculella (Zell.)
Agrotis ipsilon (Hufnagel)
Papuana aninodalis Prell
Apachyidae (DERM)
Green peach aphid
Henosepilachna signatipennis
Idopsis coerulea
Melon aphid
Phaenacantha sp.
Cassida diomma
Potato tuber moth
Cassida sexguttata
Black cutworm
Sago
Tok Pisin: Saksak
Scientific name: Metroxylon sagu Rottb.
Sago palms
There are 2 species in Papua New Guinea. The other one occurs in North Solomons Province and
in the Solomon Islands. Its scientific name is Metroxylon salomonense.
The sago palm plant
The sago palm grows up to 10 or 25 m tall and is nearly a metre across the trunk. It produces
suckers around the base. After about 15 years the main trunk produces a very large flower at the top
and then the trunk dies.
The centre of the trunk is filled with starch. The plant also produces useful building materials.
The fronds are very good house roofing material.
Drawing by Celia Bridle
31
Where does it grow?
The sago palm common in Papua New Guinea also grows in Indonesia and Malaysia.
Sago palms grow in the lower areas, up to about 1200 m.
It is very important in the Sepik and Fly River areas, in the transFly and many coastal areas
such as along the Papuan coast and Gulf region.
In the Southern Highlands in the Kutubu area (Foi and Fasu) sago is the staple food. In
other lowland areas it forms an important supplementary staple but not the main food.
But sago isn't planted just anywhere in these places, it is planted in special sago sites.
Often these are along the banks of creeks, like in the Kaluli area, or in the bottoms of valleys such
as the Kerabi Valley near Erave. At Kutubu, the sago groves fill up large swamps. People establish
and care for sago groves and these are often at some distance from the villages, as people prefer to
live in drier places.
Sago doesn't like to be in a very wet swamp and doesn't like to be in a dry place. Often
sago sites are just slightly too wet for gardening.
Varieties of sago
People in Hegiso village near Kutubu recognise and have names for at least 34 varieties
of sago. These vary from having no thorns, up to ones with very long thorns on the bases of the
fronds. The height, shape, toughness of the bark, and length of the fronds varies. Some palms
mature quickly, some have many suckers and the taste and colour of the starch varies.
Sago thorns
In other areas the people only recognise a few kinds of sago.
Sago grows from suckers to a
flowering plant over about
15 years.
Sago grubs are an important
supplement to the diet and also
important for management of palms
including thinning out of suckers.
33
Planting sago
In the Southern Highlands practically all sago is planted. One or two varieties will grow
fairly easily from seed, but most kinds are planted from suckers.
To plant sago, the planting site near a creek or in a damp place, is first cleared of trees
and rubbish. Then a sucker of a suitable variety is chosen from an old sago clump. Often the
fronds of the sucker are up to 3 m high. It is first checked to see if the sucker is old enough.
Suckers ready for planting have a tough woody connection to the base of the old palm. This is
chopped through with an axe. The sucker is then simply taken to a new site and planted in a
shallow hole. If several palms are being planted, they should be about 7 m apart. The only other
attention the new palm needs is an occasional weeding to cut back rubbish when it gets too thick.
Growth of sago palms
It takes 12 to 15 years for a sago palm to grow big enough to cut down. Palms in poor
soil grow more slowly.
Normally, one main trunk grows up, but several small suckers may shoot up around the
base. Sometimes these suckers spread out and the space between the palms becomes crowded. Too
much competition between clumps slows down the growth of the main palm, so the grove needs to
be thinned out. This is very easily done. A small hole (10 cm x 10 cm) is cut with an axe into the
top of the trunk of a sucker that is not wanted. This hole lets the sago beetle in and the sago grubs
that develop quickly kill out the sucker. They don't get into the main palm or other suckers unless a
hole is made. After a few months when the sucker is seen to be dead it can be split open to provide
a feed of sago grubs.
There is no simple way of telling when a palm is ready to harvest. By experience people
learn to recognise how big each variety should be before it is ready to harvest. If the palm were left
too long it would produce a very large flower at the top and then die. This flower would use up all
the starch in the trunk so that there would be nothing to harvest. As long as the flower has only
started to grow and the seeds haven't yet formed on it, the palm is still suitable for harvesting.
Sometimes when people are in a hurry to use a palm that isn't quite ready, they cut a hole to check
how much starch is stored inside. But sago grubs must not be allowed to get in.
After the palm has been cut and harvested another sucker grows more quickly than the
others and becomes the new main trunk. It still takes about the same time to get mature.
Harvesting sago starch
First the sago palm is cut down. Mostly this is men's work. Then the bark is split off the
trunk for about one metre along its length. Normally this bark is carefully laid out at the sides
propped up by logs so that it both makes a seat for the person to sit on and a mat for the shredded
pith of the trunk to fall onto.
Sago harvesting process
Sago in the trunk of the palm is all mixed up with the fibres of the plant. So this pith has
to be shredded up into small pieces and the starch is then washed out. Special tools are made for
pounding up the trunk. They need to be light, strong and with a hard stone (or metal) head.
In areas where sago is the main food, sago is women's work. The woman sing special
songs while they work. In areas where sago is not the main food, both men and women pound
sago.
The normal method of pounding sago is to sit at the side of the trunk, hold the sago
pounder in both hands and lift it above your head, then chop it down so that it just scrapes a thin
layer off the edge of the trunk. When a pile of shredded-up trunk has been made, this is carried
away to be washed. If a lump of the pith breaks off it is often chopped up with a bush knife or axe.
sago pounders
35
Sago washing
A framework is set up for washing sago. It needs to be near water. If no convenient
creek is nearby, a hole can be dug in the ground as this quickly fills with water in most sago places.
The water needs to be clean or the starch gets a bad colour and taste.
Sago washing apparatus
The washing framework is mostly built using the bottom section of the midrib of the sago
fronds.
The shredded pith of the palm is put into the bowl made by the fronds and the starch is
washed out by banging it with a stick, and pouring water over it. The filtered starch is allowed to
settle out in a bowl. It is then dried and taken home.
Sago storage
Some people store sago for long periods. The sago to be stored is wrapped up in a tight
bundle using leaves and bark. It is then buried in the mud. It will keep for one or two years. Sago
that has been stored has a slightly different taste, but it is still quite good to eat. The unprocessed
sago logs can be stored in water for considerable time. This is common along the Sepik river.
Sago cooking
In some areas people simply fill up a bamboo tube with sago starch and bake it near the
fire. Sometimes sago is cooked wrapped in leaves. The bamboo tube is then split open and the
sago eaten, along with greens and other foods. Occasionally people add leaves such as "tu-lip"
leaves, or okari nuts. Sago pancakes are made by spreading sago out in a hot curved frying pan
then placing another hot pan over it. Sago is often made into a porridge by dropping sago into hot
water. There are lots of other interesting ways sago can be cooked and used, but people in some
areas don't seem to use these.
Sago
processing
37
Extra food from sago
At the top of the trunk of a sago palm there is a bundle of young tender undeveloped
leaves. This is often called the palm "cabbage". It can be cut out and cooked and eaten. It is good
food.
Sago grubs, and sago starch go together. Sago grubs are grown in several different ways
in sago areas. Normally the top and bottom sections of the trunk are left for sago grubs to grow in as
these sections have less starch and more fibre and are therefore harder to work. As already
described, sago grubs are grown in suckers that are being killed. If too many palms are ready at one
time, the extra ones are cut down for grubs to grow in. Sometimes a poor tasting or very fibrous
palm is left for grubs to grow in. Particularly near Bosavi, sago grubs are also cultivated in another
palm called the fishtail palm (waiyo). It takes about 2 months for a harvest of grubs from the time
the beetles are first let into the palm.
Sago grubs are the larvae of a beetle. (Rhyncophorus spp.) They are good food being
both enjoyable and good food value.
Sago grubs – pupae, adult, larvae
Sago as food
Sago is a very good energy food. But it has very little of the growth food (protein) or
health food (vitamins and minerals). Therefore in sago areas it is particularly important to pay
special attention to the other foods that make up the diet.
The food value of 100 g of the food eaten is:-
starch
grubs
cabbage
Moisture
%
20-45
70.5
Energy
cals
285
181
Protein
g
0.2
6.1
Calcium
mg
30
461
Iron
mg
0.7
4.3
proVitA
!g
provitC
mg
Yield and work required
One sago palm may last an average family (6 people) for 4 weeks. It is worked in
sections of 60 cm to 100 cm of the trunk and 6 to 8 of these sections can be taken from one palm. A
typical routine would be for a woman to spend 3-4 hours pounding and washing one section and
this would produce about 20-25 kg of starch that would last the family for about 3 days.
Pest and Disease
Sago diseases
Sooty mould
Black mould on leaves
Fungus
Fungi
and
and
Parallel sided leaf spot
Fungus
Leaf spot
Fungus
(Also several fungi isolated from processed sago)
Borinquenia sp.
Melanographium sp
Tripospermum sp
Zygosporium gibbum
Sphaerulina sp.
Sago insect pests
Asiatic rhinoceros beetle
Cane weevil borer
Coconut leaf miner
Palm weevils
and
Taro beetles
Agapophyta bipunctata Boisd.
Trochorhopalus strangulatus Gyllenhal
Leptococcus metroxyli Reyne
Oryctes rhinoceros (L.)
Rhabdoscelus obscurus Boisduval
Promecotheca papuana Csiki
Rhynchophorus bilineatus (Montr.)
Rhynchophorus ferrugineous (Oliv.)
Rhynchophorus papuanus Kirsch
Papuana spp.
Pentatomidae (HEM) - a bug reported on coconut and
sago.
Curculionidae (COL) - a weevil reported from dead
sago palm. Adults and larvae boring into lower 40 cm
of false stem of bananas causing heavy damage over
limited area in central province.
Pseudococcidae (HEM) On sago, pineapple, coconut
Leaf spot on sago
39
Solomon's sago
Scientific name: Metroxylon salomonense
How is this sago different?
The sago palm that occurs in the North Solomons province and in the Solomon Islands is
quite different from the sago that grows in other areas of Papua New Guinea. It has a different
scientific name. The scientific name is Metroxylon salomonense. Originally, the sago in North
Solomons Province was called Metroxylon bougainvillense but now that name has been shown to
be not correct as the plant is the same as the one in the Solomon Islands.
How is it different? The leaves or fronds of this sago palm are much larger than those of the
other Papua New Guinea sago palm. As well the seeds are much larger and this sago does not
produce suckers. The stem of the Solomon's sago is also larger and the flower at the top of the
palm is very large.
Growing Solomon island sago.
This sago is grown from seeds and it does not produce suckers. The seeds are large - up to 6
cm or more across.
Solomon's sago seed - 6 cm across
This sago normally grows in drier sites than for the normal sago in Papua New Guinea. The
seeds are often planted on a bank or along a ridge away from a creek or swamp. It still grows quite
well in these sites.
How is it used?
This sago is harvested, pounded, washed and the starch collected in much the same way as
for other sago. In Bougainville, people normally only use it during times of food shortage or when
they wish to hold a feast and need large amounts of food.
41
Sweet potato
Tok Pisin: kaukau
Scientific name: Ipomoea batatas
The sweet potato plant
In Papua New Guinea the sweet potato plant is a very variable plant. It has leaves borne
singly along the vine and produces thickened tubers under the ground. But leaf shape, vine length,
tuber size shape colour and taste are some of the many things that vary to give the large number of
varieties seen throughout Papua New Guinea.
The fact that sweet potato easily flowers and sets seeds in Papua New Guinea and these
seeds grow and produce new seedling plants is probably the reason that Papua New Guinea has
developed so many different varieties of sweet potato. One of the obvious differences is in leaf
shape but many other things vary between varieties as well.
Different leaf shapes
People are continually selecting kinds that suit their purposes. Some varieties mature very
quickly. Kinds called "wan mun" have a small amount of food after 6 - 8 weeks in coastal areas.
People are also picking out kinds that give some yield under lower fertility conditions as their
garden sites get older.
For preference people tend to like a sweet dry variety that gives plenty of energy. Often the
larger softer kinds are fed to pigs.
Growing Sweet Potato
Sweet potato is grown from the tips of vines. In some areas people put three runners in
together. People often argue a lot about how many tops should be planted together. It does not
greatly affect the amount of sweet potato produced whether plants are put closely together or more
widely apart but the size of the tubers varies.
Sweet potato cannot stand water-logging. For tubers to form, there must be lots of air in the
soil. If the soil becomes too wet the sweet potato will grow lots of vines and leaves and produce
very few tubers under the ground. So probably the individual practices that different sweet potato
growers have developed in different areas of the country are methods they have learned by
experience to suit their soil and rainfall patterns. Where the soil is heavy with lots of clay it is
more important to build mounds or ridges. In some places in Papua New Guinea where people
have sandy soils they simply plant sweet potato on flat ground or sometimes with very small
mounds. This works well enough for those soils as long as there is not a lot of rain causing the soil
to be waterlogged. Once sweet potatoes have passed the particular time in their growth when the
tubers are formed, they will not later produce tubers so only tops grow and the few tubers that have
formed grow large.
Sweet potato also has another problem. Sometimes they grow too much top and produce
little food under the ground. This occurs where the soil is very rich in nitrogen as this favours top
growth but not storage of starch in tubers. Often when people see this occurring, especially in
coastal areas they go through the garden and remove some of the top growth either by breaking it
off or banging it with sticks. If a second crop of sweet potatoes is produced in the same garden it
normally doesn't happen a second time as nitrogen quickly gets used up by plants or washed away
in the rain. This problem is most common in new bush gardens.
43
In most areas of Papua New Guinea people go through their gardens several times
harvesting the tubers. They take the large ones, then allow the smaller ones to continue growing
before they are harvested later. In many areas after the third harvest pigs are allowed to forage in
the gardens and eat the vines and tubers. This is one efficient way to clean up gardens but it is
possibly for pigs to spread some diseases from one sweet potato crop to other areas if not careful.
eg Sweet potato black rot.
DISEASES
Leaf spot
Collar rot
Leaf spot
Black rot
Leaf spot
Scab
Scurf
Leaf spot
Stems with internal browning
Leaf spot
Leaf spot
Soft rot
Tuber rot
Fusarium wilt & tuber rot
Storage rot
Blue mould rot
Charcoal rot
Little leaf & vein clearing
Potyvirus leaf curling
Root knot
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Bacteria
Bacteria
Fungus
Fungus
Fungus
and
and
Fungus
Fungus
Mycoplasma like organism
Virus
Nematode
Leaf spot (Pseudocercospora timorensis)
Small angular brown spots develop on the
leaves of sweet potato. They are due to a fungus.
The spots are mostly on the older leaves and
they become more common in old garden sites where
soil fertility is getting low. They are also worse in the
wet season.
Leaves fall off slightly early but the disease
appears to do little damage.
Ascochyta convolvuli
Athelia rolfsii
Cercospora bataticola
Ceratocystis fimbriata
Didymella sp.
Elsinoe batatas
Moniliochaetes infuscans
Phoma sorghina
Phomopsis ipomoea-batatas
Phyllosticta sp.
Pseudocercospora timorensis
Rhizopus stolonifer
Botrydiplodia theobromae
Erwinia sp.
Erwinia chrysanthemi
Fusarium sp.
Fusarium oxysporium
Aspergillus sp.
Choanephora sp.
Mucor sp.
Penicillium sp.
Macrophomina phaseolina
Meloidogyne sp.
Scab (Elsinoe batatas)
Brown scabby spots can often be seen on the
veins of the leaf and along the vine of the sweet potato
plants. The leaves become twisted and often the tips
of the branches stick upright.
Some varieties of sweet potato get the disease
less than others. Most varieties of sweet potato in
Papua New Guinea seem to have a sufficiently high
level of resistance to this disease for it to not get too
bad. The yields are reduced.
Fusarium wilt
In the Upper Mendi and Upper Karint areas
sweet potato tubers are rotting and plants are growing
leaves only. The stalk which joins the tuber to the
plant has rotted off. If the tuber is cut in half or if the
stem is cut open a dark brown ring can be seen. This
ring is because a fungus has got into the plant and
blocked the conducting cells where food and water
pass up and down the plant. Normally it is root knot
nematode which first damages the skin and lets the
fungus get inside. The very small worm like
nematodes normally twist roots into knots but when
this fungus gets inside the roots do not form these
galls.
Insect damage
Some of the leaf-chewing insects on sweet potato do not do serious damage as sweet potato
often grows an excess of leaves especially in fertile gardens and in coastal areas.
Insects
Sweet potato hawkmoth
Sweet potato leaf miner
Sweet potato weevil
Cacao armyworm
Cacao false looper
Cacao looper
Cacao mirid
Grass bug
Horned weevil
Grasshopper
Pumpkin beetles
Sugarcane aphid
Taro hawkmoth
Tobacco whitefly
Leaf eating beetle
Sweet potato stem borer
Sphingidae (LEP)
Lyonetiidae (LEP)
Curculionidae (COL)
Acrididae (ORTH)
Noctuidae (LEP)
Noctuidae (LEP)
Geometridae (LEP)
Coreidae (HEM)
Miridae (HEM)
Curculionidae (COL)
Tettigoniidae (ORTH)
Chrysomelidae (COL)
Aphididae (HEM)
Sphingidae (LEP)
Aleyrodidae (HEM)
Arctiidae (LEP)
Coccinellidae (COL)
Pyralidae (COL)
45
Agrius convolvuli (L.)
Bedellia somnulentella (Zeller)
Cylas formicarius elegantulus (Summers)
Atractomorpha crenaticeps Blanch
Tiracola plagiata Walk.
Achaea janata (Linnaeus)
Ectropis bhurmitra Walker
Helopeltis clavifer (Walker)
Halticus tibialis Reut
Apirocalus cornutus (Pascoe)
Phaneroptera brevis Serv
Aulacophora spp.
Aphis sacchari Zehntner
Hippotion celerio (L.)
Bemisia tabaci (Guen.)
Argina cribraria (Clerck)
Epilachna signatipennis Boisd.
Omphisa spp.
Cacao armyworm Tiracola plagiata Walk is a Noctuid moth or an
armyworm that attacks many different plants. It is a semi looper that means
it has less than the usual 5 pairs of legs on the abdomen of the caterpillar.
The moth is a light grey moth with a "V" mark on the front wings.
Caterpillars feed on leaves at night. They gather together in groups and are
therefore called armyworms. The larvae eat young soft growing parts of the
plants and can also eat weeds and other bush trees. The insect tends to build
up on trees like leucaena shade or other large areas of one crop then spread in
plague numbers into surrounding gardens. Mixed cropping helps keep a
balance of insects and their predators. Outbreaks can be predicted by
trapping moths in light traps. Some predators and parasites operate but they
do not exert enough control to stop a strong outbreak. Carbaryl insecticide
will control them.
Cacao false looper Achaea janata (Linnaeus) is the larva of a moth. The
mature larvae are grey with a spotted head and a coloured stripe along the
side. It is 60 mm long. A life cycle egg to egg takes 32-38 days. The larvae
eat a range of young soft leaves especially castor but also damage sweet
potato, peanuts, citrus, cacao, rubber, pumpkins etc. They occur up to 1900
m altitude.
Cacao looper Ectropis sabulosa Warr. The larvae of this moth move by
forming a loop. They can build up into large numbers given the right
conditions. That is where the two common names come from. It eats the
young leaves during the flush of growth of cacao. It also damages sweet
potato, cassava, taro, peanuts and coffee by eating the leaves. Large
outbreaks of these insects normally die out naturally due to predators.
Cluster caterpillar Spodoptera litura (Fab). The adult moth is 18 mm long
with a brown body. The wingspan is about 40 mm. The front wings have
silvery marks and the hind wings are silvery white and you can almost see
through them. This moth is attracted to lights at night. The larvae are dark
brown above and green beneath with a light band along the side. Larvae are
45 mm long and cluster together. They damage a range of crops. Quite often
the damage is only slight but in some seasons they can do extensive damage.
They move between crops and the numbers depend on the climatic
conditions. Sometimes, control can be achieved by removing and destroying
leaves that have large numbers of caterpillars on them. On taro, the young
caterpillars can be collected in a paper bag and burned. Control can be
achieved with contact insecticides such as carbaryl.
Corn earworm Heliothis armigera (Huebner). The moths vary in colour but
are generally brown to grey with dark irregular markings across the front
wings. They are darker towards the tip with a pale band near the edge and
with a dark spot almost near the centre. Adult moths have a wingspan of 35
mm. They fly at night. Moths lay up to 1550 eggs. The larvae feed on leaves
and fruit. They damage a range of plants. They can cause serious damage to
corncobs and tomato fruit. Rain helps the pupae develop and warm moist
weather makes the pest worse. In the highlands the occurrence is probably
seasonal with a lull early in the year then in Aug/Sept. The insects have a
number of parasites and predators therefore for these to build up and be able
to control the insect, it is important to restrict spraying as much as possible.
A fungus disease grows on the insects in the highlands and is favoured by
wet conditions. The larvae become dark and move slowly. White fungal
threads turn green and become powdery. The larvae can also be shaken off
the plants and then killed.
Sweet potato hawkmoth Agrius convolvuli L. The adult is a large
hawkmoth with grey wings and pink and black banded body. The wingspan
is 75-120 mm and the body 45 mm long. The wings have irregular light and
dark patterns. The adults fly near sunset. They are strongly attracted to
lights. Adults can fly long distances. (Thousands of kilometres.) The adults
can suck nectar from flowers by hovering near sunset. They larvae eat the
leaves of sweet potato and also damage taro. The larvae feed on the underside
of the leaves. It is more serious in coastal areas and is mainly below 1500 m.
It is also worse in dry weather. There are natural parasites and predators that
help control. Digging the ground to expose pupae reduces the number. The
larvae can be picked off leaves by hand. Plants can be sprayed with carbaryl
insecticide. (But this should rarely be used as people eat both taro and sweet
potato leaves. The young larvae that need to be sprayed are on young leaves
that people eat.)
Sweet potato leaf miner Bedellia somnulentella (Zeller). The larvae of this
very small moth burrow into sweet potato leaves. The larvae are small green
caterpillars. Adult moths are 3 mm long and brown to grey in colour. A life
cycle takes 3-4 weeks, so pest numbers can build up quickly. The larvae or
caterpillars can be up to 7 mm long and at first make straight mines in the
leaves but later they mine out blotches of tissue. Only occasionally do large
outbreaks of these caterpillars occur. Mostly they are controlled by parasites
and predators. Care with chemicals is important as it can upset the balance of
predators and parasites. If it is necessary to spray, a range of chemicals will
kill the larvae but not the pupae. Therefore it is necessary to spray twice
about a week apart.
Sweet potato vine borer Omphisa anastomosalis Guenee. Larvae are
yellowish with brown hard plates. Up to 3 cm long. Adult lays about 300
eggs on underside of leaves and pupae form in the tuber. Larvae burrow into
leaf stalks then burrow downwards. A life cycle takes about 55 days. When
larvae bore into vines it is claimed that the tubers are reduced in size.
Infested sweet potato start to wilt in dry weather. For control crop rotation is
important.
Taro hawkmoth Hippotion celerio (L.). The adult moths have small silvery
markings on light brown torpedo-shaped bodies. They fly at night with a
whirring sound. The front wings are brown with a silvery stripe and the rear
wings are brown with a black central patch and bright pink near the body.
The larvae are up to 60 mm long. They are green or brown with a large
eyespot on the fourth body segment and a small yellow eyespot on the fifth
segment. The horn on the rear end is straight and black. The larvae eat the
leaves and can do serious damage. They are normally under the leaf and eat
the edges of the leaf. They eat taro and sweet potato leaves and grapevine
leaves. The loss of some of the leaves does not necessarily reduce the yield. It
is possible to pick the caterpillars off by hand. Carbaryl insecticide can be
used. It has some parasites and predators that help control.
Vine hawkmoth Theretra oldenlandiae Fabricius. These moths are similar
to sweet potato hawkmoth but have no pink areas on the hind wings. The
moth has a wingspan of 60 to 75 mm. The larvae feed on grapevines, sweet
potato, taro etc.
47
Black flea beetle Arsipoda tenimberensis Jacoby. This insect damages sweet
potato leaves, corn, common bean and soybean and probably some other
plants. The insect causes characteristic damage. It is widespread but the
damage is normally not important.
Horned weevil Apirocalus cornutus (Pascoe). They occur up to about 1600
m altitude and damage a range of plants. The insect mainly attacks growing
points and soft shoots. It chews the leaves eating holes and this is often
called shot hole damage. Other insects do similar damage. The damage is
often not serious. The weevils can be picked off plants and drowned in a tin
of water that has a little kerosene on the surface. Chemical control is not
easy.
Monolepta beetles Monolepta spp. are similar to pumpkin beetles. They
damage leaves and flowers of cassava, corn, mungbeans, pumpkins,
cucumber, and sweet potato. They feed on young shoots.
Pumpkin beetles Aulacophora spp. The adults feed on flowers and leaves.
They eat the leaves. The larvae tunnel in stems and attack roots. They can
be stopped with a dust such as Derris dust. An insecticide such as Malathion
can be used.
Small tortoise beetles Cassida spp. Feed on sweet potato leaves as well as
lettuce and potato. Damage is normally minor.
Sweet potato weevil Cylas formicarius elegantulus (Summers). This is a
small shiny blue/black ant-like insect. The adult rarely flies but they can fly
up to 1.5 km and they are very poor at burrowing in the soil. It is about 5-6
mm long. Adults feed on leaves and stems. They can live for several
months. Eggs are laid in holes in vines or tubers and hatch in 1 week. Pupae
are in the tuber or stem and last for one week. Larvae are white and legless
7-8 mm long and burrow into vines and tubers. 14 days. A life cycle takes
about one month. There can be 8 generations per year. They can cause
serious damage in cracking soils and in old gardens. When they burrow into
sweet potato stems and tubers, tubers get a bitter taste and bad smell.
Damage is worse in dry weather. The insect thrives under warm moist
conditions. Insects can also live on other sweet potato family plants. Crop
rotations prevent large numbers building up. A one-year break between
crops and one kilometre between gardens is needed. Mounding soil around
sweet potatoes especially in places with cracking soils. Be careful not to take
weevils to new gardens in planting material. Deep rooting kinds and fast
maturing kinds of sweet potato get less damage. Get rid of old sweet potato
vines after the crop is harvested. Pigs or other animals can be used to clean
the gardens. Insects can also breed in sweet potato family weeds eg morning
glory. Harvest the crop as soon as it matures. Damage can occur after
harvest. Plant kinds of sweet potato that get less damage. Planting material
can be dipped in Malathion insecticide.
Taro beetles Papuana spp. The adult beetles are brown to black and with
strong legs for digging. The insects are 15-25 mm long and the wing covers
do not quite reach the end of the abdomen. There are one or more small
horns on top of the abdomen. They fly at night. Adults can live for 150
days. Eggs are laid in the soil near grasses etc 50-150 mm deep. Larvae are
white curl grubs and feed on plant roots. Pupa can be 200 mm to 1 m in the
soil. Control is very difficult. Garden location influences the amount of
damage. Barrier crops around the edges of gardens possibly helps control.
Some varieties get less damage.
Tortoise beetles Aspidomorpha spp. The adults are round insects often with
bright colours. A life cycle may take 4-6 weeks. The adults and larvae eat
holes in sweet potato leaves and eventually all the leaf between the veins can
be eaten away. They also eat aibika. They are normally not a major pest.
Old sweet potato plants and other plants in the same family can act as places
for the insects to breed so these should be removed. Spraying with carbaryl
insecticide works (0.2% solution). Often control is not necessary.
Amblypelta bugs Amblypelta spp. They suck sap and secrete a toxic saliva.
A few insects can cause extensive damage. They attack a range of other
plants. They can cause plants to wilt and fruit to drop off.
Black leaf-footed bug Leptoglossus australis (Fab.) This bug damages at
least 26 different species of plants. The insect occurs in most districts of
PNG at most temperatures and localities, wet and dry, grassland and forest up
to 1750 m altitude. The young stages and adults suck the sap, causing plants
to wilt. It is common but not very serious. Control measures are not normally
required.
Cacao mirid Helopeltis clavifer (Walker). They have piercing mouthparts
that secrete a toxic substance that produces a dead spot on the plant. They
can cause the death of the terminal bud and growing shoot of plants. One
insect can make 50 feeding punctures a day. Young fruits can die and older
fruits can be deformed. They have been recorded damaging 25 species of
plants in PNG. The insects occur from sea level up to 1670 m altitude.
Infestation is often only to a section of the crop or tree.
Grass bug is also called sweet potato mirid. Alticus tibialis Reut. This bug is
about 20 mm long and black. It jumps. It is widespread on sweet potato and
reputed to be vector of "little leaf".
Tobacco whitefly Bemisia tabaci (Guen.). These are very small white
whiteflies. Adults are about 1 mm long. Larvae do not move much. The
whitefly is mostly found on the lower leaf surface. If the leaves are shaken a
cloud of small moth-like insects flutter out but resettle. The young insects
suck sap, causing leaves to turn yellow, wilt and die if there are large
numbers of insects. They spread viruses. They also secrete honeydew
causing sooty mould fungi to grow. Damage is more common during the dry
season and they disappear when rain starts. Control is not normally needed.
Atractormorpha crenaticeps Blanch. This grasshopper is uniformly green or
light brown with pale pink hind wings. This grasshopper damages the leaves
and tends to do damage in moist places.
Mole crickets Gryllotalpa africana Pal. The adult is a brown cricket about
25 mm long with a velvety appearance. The front legs are specially adapted
for digging. Males are heard chirping in the evening. The eggs are oval
brown and 1.5 mm long. It attacks many crops at the seedling stage. Roots
are damaged and plants wilt. It is worse at lower altitudes and in moist soil.
It can burrow deeply into the soil. Most of the damage is to seedlings as the
insects burrow just below the surface. They can feed on sweet potato below
the ground.
Phaneroptera brevis Aud.-Serv, is a long horned grasshopper common in the
highlands. It is fairly narrow. Antennae are 3-4 times the length of the body.
Females lay up to 60 eggs over 3 months. It attacks sweet potato by eating
the leaves. It is often found in shady places. Control is usually not
necessary.
49
Other minor pests
Adoxophyes sp
Reported damaging sweet potato.
Tortricidae (LEP.) -leaf roller
Aedia sericea Butler
Noctuidae (LEP.)
Frequent in small numbers in sweet potato in highlands.
Antestiopsis chambereti Le Guillon
on sweet potato
Pentatomidae (HEM.)
Aphthona bicolorata Jacoby
Chrysomelidae (COL.)
Doing minor damage feeding on the leaf epidermis of sweet potato.
Argina cribraria (Clerck)
Arctiidae (LEP.)
On sweet potato and Crotalaria. An orange spotted moth. There are white edged spots
on the front wings and darker spots on the rear wings. Larvae feed within the seedpods
of crotalaria. Caterpillar is black with yellow rings across the body and with long black
and white hairs. There is a row of orange spots along the side. They are up to 25 mm
long.
Asura crocota Hampson
Arctiidae (LEP.)
Larvae reported boring superficial channels in stored sweet potato tubers in the
highlands.
Atysa sp.
Chrysomelidae (COL.)
Reported on leaves of sweet potato and also pollinating plant.
Cassida spp. small tortoise beetles reported feeding on sweet potato leaves in small
numbers and doing minor damage.
Cicadella wallacei Distant
sweet potato in highlands.
Cicadellidae [Jassidae](HEM.) On
Clysterius angustus Arrow
potato
Scarabaeidae (COL.) In sweet
Colasposoma regulare Jacoby
Chrysomelidae (COL.)
On leaves and stems of sweet potato. Makes small round holes in sweet potato.
Dendrothripoides ipomoeae Bagn.
Thripidae (THYS.)
Feeding on sweet potato leaves causing yellow freckling.
Epilachna signatipennis Boisd.
beetle reported damaging sweet potato.
Coccinellidae (COL.) leaf eating
Idopsis excellens Faust.
Reported damaging sweet potato leaves.
Curculionidae (COL.)
Kolla sp.
Cicadellidae (HEM.)
Reported damaging sweet potato leaves causing brown spotting.
Nysius villicus Van Duzee
Lygaeidae (HEM.)
Reported sucking on sweet potato. They are inconspicuous greyish brown bugs 3-4mm
long. The damage is normally unimportant. They normally live on weeds.
Onchyrotica concursa Walker
Pterophoridae
Larvae on sweet potato. Larvae fold and web leaves.
Solephyma papuana
Galerucidae (COL.)
damaging sweet potato
Reported
Tabidia insuralis Snell
Pyralidae (LEP.)
Reported causing extensive windowing of sweet potato leaves in lowlands. They tie
leaves together and chew the leaves.
Teleogryllus commodus Wlk.
potato.
Gryllidae-field cricket. In sweet
Zygina medioborealis Ghauri
sweet potato in highlands.
Cicadellidae (HEM) Common on
Sweet potato weevil damage
Armyworm damage
51
Taro family plants
Taro tru
Colocasia esculenta
Chinese taro
Xanthosoma sagittifolium
Taro
plants
Giant taro
Alocasia macrorrhiza
Elephant foot yam
Amorphophallus paeoniifolius
Swamp taro
Cyrtosperma merkusii
Chinese taro Xanthosoma sagittifolium
Taro tru Colocasia esculenta
Swamp taro Cytrosperma merkusii
Giant taro Alocasia macrorhiza
Elephant foot yam Amorphophallus paenifolius
53
Chinese taro
Tok Pisin: Singapo; taro kongkong
Scientific name: Xanthosoma sagittifolium
The Chinese taro plant
This plant looks a bit like taro tru but the leaves are bigger. The leaf is also divided near
where the leaf stalk and blade join and there is a distinct vein around the edge of the leaf.
Under the ground the plant produces a ring of small corms around a large central stem or
corm. It is these that are eaten.
These taro plants can grow up to 2 metres tall although an average plant is probably only a
metre tall.
Where does Chinese taro grow?
Chinese taro will grow well from sea level up to about 1600 metres above sea level.
Sometimes it is seen growing at higher places than that, but it doesn't produce very well.
Chinese taro is one of the newer taros to Papua New Guinea and it is still being introduced
to some areas of the country. In the Southern Highlands it was brought in by the first people that
landed by plane at Lake Kutubu.
People in mid altitude areas use Chinese taro very commonly. At Kutubu, and similar
lowland areas it is one of the most commonly used root crops. In the Gazelle peninsula where
people are very short of land they grow Chinese taro under cacao and coconuts.
Chinese taro is suited to high rainfall areas.
How is Chinese taro planted?
Chinese taro is normally planted by using the top piece of the main central corm or stem. It
can also be grown by using the small side corms; or pieces of the corm can be used as long as they
have some buds on them.
They can be planted at any time of the year but in dry areas the middle of the dry season
should be avoided. Plants are spaced at varying distances but there is often about 0.9 m x 1.5 m
between plants.
What conditions does Chinese taro like?
Chinese taro grows better in good soils especially ones with plenty of nitrogen. But is can
be grown in relatively poor soils and still give a satisfactory amount of food. Where the soil is hard
and compact, much less food is produced.
55
This taro like most other taro family plants can also be grown in light shade. It is often
grown near bananas and other taller plants.
The places where it has become a major crop mostly have a deep soil that has been washed
there by water (alluvial) and a well-distributed rainfall. In these places it is a very easy crop to
grow and requires very little maintenance or re-planting. It does not do well in waterlogged soils.
The soil water level must be at least 45 cm below the soil surface for Chinese taro to produce
properly.
When is the food ready and how is it harvested?
Sometimes a crop of corms can be harvested after 7 or 8 months but often plants take up to
one year to grow a good crop. Where plants are on hillsides the corms are often harvested without
actually digging out the whole plant. The soil is carefully dug away from the plant and the small
corms are broken off the parent plant. The main stem is then covered to produce a new crop.
Chinese taro gardens often stay in the same place for many years and corms are just
harvested with only occasional or irregular re-planting.
The corms will store reasonably well under dry, cool, well-ventilated conditions. The corms
will also remain in good condition if they are left growing in the ground and just harvested when
needed.
Chinese taro as food
Mostly only the young corms are eaten. The main stem or corm can be eaten but often it
contains oxalate crystals so that it burns the throat.
The young leaves can be boiled and eaten as an edible green or kumu.
Some idea of the amount of different nutrients that are contained in a 100 gram portion of
the part that is eaten are given in this table.
Moisture Energy Protein
%
cals
g
Corms
70-77
1.3-3.7
Leaves
2.4-4.1
Calcium
mg
Iron
mg
proVitA
!g
provitC
mg
The corms are mostly peeled then boiled or roasted. Many people do not like Chinese taro
as much as some of the other root crops but they grow and use it because it is easy.
Pest and Disease
Chinese taro suffers little from serious pest or disease problems. Sometimes the corms are
damaged by taro beetles or rats. Sometimes the leaves are attacked by small sucking insects, like
coconut scale and cotton aphid.
Corm rots, especially during storage, can be a problem if corms are damaged or poorly
stored.
Chinese taro does not get the taro blight disease that is causing so much trouble with taro tru.
But it can get some fungal leaf spots.
But because at present Chinese taro does not suffer serious pest and disease problems it
should not be assumed that problems cannot occur. Root rot problems have occurred both in Ghana
and East New Britain. These problems arose where soil fertility was low, plants were continuously
replanted in the same area and a fungus such as Corticium rolfsii attacked the roots and virus like
symptoms showed up on the leaves. Plants died.
Chinese taro leaf spot
Chinese taro root rot
57
Chinese taro diseases
Root rot
Fungus
Fungus
Fungus
Fungus
Phytophthora citricola
Phytophthora nicotianae
Pythium arrhenomanes
Pythium vexans
Leaf spot
Chinese taro insect pests
Taro beetles
Coconut scale
Armoured scale
Armoured scale
Soft scales
Yam mealy bug
Mealy bug
Longtailed mealybug
Scarabaeidae (COL)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Margarodidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Papuana spp.
Aspidiotus destructor Signoret
Chrysomphalus dictyospermi (Morgan)
Hemiberlesia palmae (Cockerell)
Icerya seychellarum (Westwood)
Planococcus dioscoreae Williams. On Chinese taro in storage
Planococcus pacificus Cox
Pseudococcus longispinus (Targioni)
Nutrient deficiencies
What signs does a plant show when it is short of soil nutrients?
When nitrogen is in short supply plants are small with pale green leaves and short leaf
stalks. Growth is slow.
Phosphorus shortage also makes plants small and growth slow but the leaves remain dark
green.
Magnesium shortage results in a bright orange colour developing between the veins. The
leaf dies.
Calcium shortage causes old leaves to be thick and leathery but young leaves are small and
twisted with dead and pale patches.
Elephant foot yam
Scientific name: Amorphophallus paeoniifolius
What is the plant like?
The plant has one straight leaf stalk and then a very divided and irregular leaf at the top.
People in villages know a wild form of this plant. The stalk or leaf petiole is very rough.
This kind is never eaten because it contains large amounts of a poison called oxalate that burns the
throat and irritates the skin. The kind that is grown and eaten has a smooth leaf stalk.
The large round underground corm produces small corms around the side. These are usually
used for planting.
After the leaf dies back, a very large lily type flower is produced. This flower has a strong
smell, like rotting meat, which attracts flies to pollinate the plant.
59
Names
This plant produces a large round underground corm. That is how it got its name "elephant
foot". But it is not a yam, as the flower and the taste of the plant show it really belongs to the taro
family.
Scientists have recently changed the names of these plants. The old name was
Amorphophallus campanulatus but now the correct name is Amorphophallus paeoniifolius. There
are two varieties: var. hortensis which is the cultivated kind with smooth leaf stalks, and var.
sylvestris which is the wild kind with rough green leaf stalks.
How does the plant grow?
Small corms from around the side are the normal part planted. If a very small corm is
planted, the plant may need to grow for several seasons to produce a large yield. After harvest, the
corm needs to be kept for a few months before it is ready to produce a new shoot and re-grow.
When it is planted a single leaf stalk is produced and the irregular shaped leaf is produced at the top
of the stalk. Eventually the corm under the ground increases in size then the leaf dies back. The
corm could be harvested and stored, or eaten at this stage. If it is just left, a very large flower is
produced. After a while this flower produces a strong smell like rotting meat.
This type of growth pattern where the plant grows leaves and produces a corm or tuber that
then can be stored and needs to be kept before it re-grows, is the type of growth that suits areas with
a distinct wet and dry season. It has the advantage that the corm will store well after harvest and
can be eaten in the dry season when food is short.
Where does this plant grow?
In Papua New Guinea this plant is grown occasionally in several coastal areas. It can be seen
in Sepik gardens and in Milne Bay. It is also grown in several other tropical countries. It is
common in some areas of India and is grown and used in Fiji, the Philippines and Indonesia.
Giant taro
Tok ples: Paragum (Kuanua)
Scientific name: Alocasia macrorrhiza
What is the giant taro plant like?
This is a taro family plant. It grows as a large upright plant that can be up to 3 metres tall.
The tuber or rhizome grows above the ground and is the part eaten. It is only eaten in some
varieties and is not commonly used except in a few places in Papua New Guinea.
The leaves are large and upright. The leaf blade continues straight on at the same angle as
the stalk and is not bent back at right angles. The leaf is shiny and often the edge of the leaf is
wavy. The bottom lobes of the leaf are rounded.
The stem or rhizome is thick (10-15 cm) and often extends along the ground or curves
upwards at an angle. Brown trailing fibres of the leaf bases often hang from the stem. Small round
side shoots grow from this stem.
Giant taro
61
Where do giant taros grow?
In Papua New Guinea Giant Taro or Paragum can be seen growing wild near creeks and in
the bush in many parts of the country. They grow from sea level up to about 2700 metres altitude.
But in most places these plants are wild and not eaten for food. They are very bitter.
In a few areas this taro is grown in food gardens as a food. At Namatanai in New Ireland
Province, and amongst some of the Tolais near Rabaul it is commonly grown and used.
The same plant has been recorded as an occasional food plant in a number of Pacific
countries, the Philippines and in Indonesia and Malaysia, Taiwan and India.
How are Giant Taros grown?
Small shoots or corms develop along the sides of the stem of the main plant. These can be
removed and planted. But growth from them is very slow.
It is better to use the top piece of an old stem once the plant has been harvested. Pieces of
the stem can be used. Plants need to be 1 to 1.5 m apart.
Because the giant taro takes more than a year to be ready to harvest, it often ends up left
growing in an old garden site after the other plants have been replanted in a new garden. The giant
taro is simply left to grow without much care or weeding, until the owner wants to harvest it.
Preparing and cooking giant taro
Giant taro contains small needle-like crystals in the tissues. These are due to a chemical
called calcium oxalate. It is necessary to remove these during the preparation and cooking. The
method of peeling is important. Normally some ladies who are especially experienced at peeling do
this job. Also the taro corm is often left to wilt for a week after it is harvested and before it is used.
Also to help remove some of the crystals, the stem is baked for a long time, or boiled in
several changes of water.
It is also important to use the right variety of giant taro because the kinds grown in gardens
have less of the chemical than wild ones.
What conditions does giant taro require?
Giant taro is a tropical plant and will not grow well below 10°C. It requires a welldistributed rainfall and does not tolerate drought. Even though it grows along creek banks it cannot
tolerate waterlogged soil.
Swamp taro
Scientific name:
Cyrtosperma merkusii
The plant
This taro family plant can be picked out from other commonly grown taro plants by the
pointed ends to the leaf lobes. The leaves are arrow shaped and point upwards. But other aspects
of the plant can vary. Some kinds are more spiny on the leaf stalks than others.
The plants can grow up to 4 metres tall. Under the ground there is a large fattened rhizome
or corm. This is shaped liked a cylinder and can be up to 70 kg in size.
The plant produces a lily type flower that then produces a group of seeds that are orange in
colour.
The plant produces suckers. The number of suckers varies with varieties. Some countries
have up to 15 varieties of this taro.
Drawing Celia Bridle
Naming of the plant
In the past scientists have often called this plant Cyrtosperma chamissonis and sometimes
Cyrtosperma edule but these names have now been changed to Cyrtosperma merkusii. This type of
confusion sometimes occurs when a plant varies as much as this one and scientists think the one in
another country is a different plant. A scientist who worked in Papua New Guinea took 3 years to
sort out the correct naming of this group of plants.
63
Where does the plant occur?
As a food plant in Papua New Guinea this swamp taro is mainly grown and eaten on Manus
Island, The Trobriands, the Mortlock Islands and in some areas of Bougainville and Buka Island.
In Kiribati, a Pacific Island nation, this plant has been one of their main traditional foods. It
was grown in pits dug into the coral atolls. It is also grown and used in Malaysia, Indonesia and the
Philippines as well as some other Pacific Island countries.
Taro
Tok Pisin: taro tru
Scientific name: Colocasia esculenta
The taro plant
The taro tru plant is an upright plant with large leaves carried on a long, often striped,
petiole.
The petiole joins this large leaf blade away from the edge towards the centre of the leaf.
At the ground level it has a large fattened base to the stem that is called a corm. Around this
corm small buds produce a circle of suckers or small side plants.
As plants get older, particularly if a dry period occurs, the taro plant will produce a lily type
flower in the centre. When this is pollinated it produces a green fruit that turns orange. Inside this
there are some thousands of small seeds.
Drawing Celia Bridle
65
Kinds of taro
Scientists recognise two different kinds of taro tru.
They give them slightly different scientific names.
And
Colocasia esculenta var. esculenta
Colocasia esculenta var. antiquorum
The first one is for the taro that is grown in most areas of Papua New Guinea that has a ring
of small leafy suckers and new plants are grown from the tops of main plants or young leafy
suckers. The other plant actually has all the leaves dry off and it has a period when the plant can be
stored. The suckers are larger. This plant mainly occurs in very dry areas such as the Western
District.
A plant looks like this after the leaves have dried off. The leaves and plant when growing
look much the same as the ordinary taro.
Dasheen type of taro
The main type of taro tru comes in many different varieties. These can be picked out by the
colour of the leaf stalk and by looking at many other details of the plant. The differences between
all these kinds are important to taro growers.
Where does taro grow?
Taro will grow from sea level up to about 2300 metres altitude. It needs an average daily
temperature above 21°C. This means that most gardeners in Papua New Guinea have the chance to
grow taro if they want to. In fact most families grow at least some taro. It is a crop that particularly
suits hot humid places like coastal areas of Papua New Guinea. In the past it has been very
important but some diseases such as taro blight and virus diseases means that it is now less grown
in areas like Bougainville, the Gazelle peninsula and Manus. It also needs a fertile soil and other
crops such as sweet potato and cassava will grow on poorer soils.
Taro needs some special conditions to grow well. It needs to have a fertile soil, and it needs
plenty of water. So in most places taro is put first in a rotation after land is cleared from bush.
Otherwise it is put on fertile soils near rivers.
Because taro can also stand a reasonable amount of shade, it is particularly suitable for
growing in newly cleared rainforest in places with high rainfall. Near Mt Bosavi, the Kaluli people
have these conditions and they have also developed a special gardening technique. They clear the
undergrowth, plant their taros and bananas, then cut the trees down over the top of the crop. The
taros and bananas grow up through the fallen leaves and branches. Just because taro will grow
reasonably well in shade it normally still grows better in full sunlight. Taro tru needs more sunlight
than Chinese taro.
The Huli people near Tari often grow taro along the edges of the drains that they are so
specialised at digging. Here the taro can get moisture and good fertile soil. In other areas people
find the right conditions for taro either at the bottom of a deep limestone sink-hole such as on the
Nembi plateau or at Erave; or beside a creek or river or at the bottom of a small valley. Often taros
are put near houses where the soil fertility can be built up with household scraps and rubbish.
In some areas of Papua New Guinea people grow taro as a flooded crop where they make a
shallow pond and then grow the taro in the water. Normally water is provided for the pond by as
system of irrigation so that the water doesn't become stagnant and cause the taros to rot. This
method is also used in some other Pacific countries. (Some other taros such as swamp taro are also
grown in water.)
How can you grow taro?
Taro is grown from the top piece of a corm, or from side suckers. When tops are used, leaf
stalks about 20 cm long are left attached to a piece of the corm about 1 cm thick. As a general rule,
larger tops grow faster and give larger corms. Often when side suckers are used they are stored in a
nursery beside a creek until needed. It is possible to get taro buds on taro roots to grow and produce
several new plants if the growing tip is removed. This is a way to increase the amount of planting
material.
The top or sucker is planted in a hole. The hole should be 10-20 cm deep. Normally it is
made with a digging stick or a spade. Putting taro in pits or holes gives better taros than by planting
on flat ground or raised beds. A normal spacing for taro is to put one plant on each square metre of
ground.
A taro top in
a planting hole
67
Taro can be planted at any time of the year but it is often fitted into a seasonal pattern to suit
the rainfall and other gardening conditions. It does not grow well in dry periods so planting is often
arranged to avoid these in coastal areas.
Dr Sutherland in his book, Introduction to Tropical Agriculture shows the growth of a taro
crop and the taro plant looking like this.
Initially there are lots of leaves and these increase in size, then the corm forms and the
leaves get smaller and fewer. Although weeds growing in a taro crop affect the size of taro the
effect is worst when weeds are left growing at an early stage of the crop when the taro leaves are
small and it cannot compete as well. During the growth of a normal taro crop between 7 and 9
weedings may be needed. Allowing weeds to keep growing reduces the size of the taros and as well
the number of suckers produced. As with most crops, weed control is less of a problem in the
highlands.
Putting mulch around taro plants normally gives a higher yield. This is probably because it
helps weed control and well as keeping moisture in the soil.
On the coast taro is often ready for harvest after about 5 or 6 months but in the highlands it
is often 10 or 12 months before corms are large enough for harvest.
Often people in taro growing areas insist that taro should either be grown on its own or with
only certain other plants intercropped with it. This is probably a practice that has developed with
experience as it has been shown that taro can restrict the growth of some other crops such as beans.
Taro as food
Taro corms can vary in how much water they contain. This can vary between 58% and
75%. Papua New Guinea farmers normally prefer drier types as these give more energy for work.
Large softer kinds are given to pigs in some areas.
Some taro varieties burn the throat due to chemicals called oxalates and possibly some other
chemicals. This means that in all kinds of taros there are also wild kinds that grow along creeks etc
and these are often not used. In gardens the amount of these oxalates is influenced by the amounts
of fertiliser used. Adding extra potassium and nitrogen can increase the amounts of oxalates.
Taro starch grains are very small and this makes it a very easily digested food.
Taro leaves are very good quality food. Young taro leaves are commonly cooked and eaten
and one taro leaf per day is enough to meet the vitamin A needs of three small children.
The leaf stalks of taro can be cooked and eaten.
Protein is an important part of food for health and growth. Taro corms contain between
1.7% and 4 % on a dry weight basis. This varies with variety and also the fertility of the soil. The
protein content also gets less as corms get older.
/ 100 g edible portion
Moisture
Energy
%
KJ
Corm
66.8
1231
Leaves
85.0
210
Leaf stalks
93.0
101
Protein
g
1.96
5.0
0.5
proVit A
µg
3
424
180
proVitC
mg
5
90
13
Diseases
Taro
Leaf spot
Blossom blight
Brown leaf spot
Leaf spot
Mitimiti disease
Leaf spot
Leaf spot
Shot hole
Blight
Leaf blight
Root rot
Mosaic
Dwarfed plants
Root rot
Root knot
With corm rot
Corm and stem rot
Bacterial leaf blight
Fungus
Fungus
Fungus
Fungus
Unknown
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Virus
Viruses
Fungus
and
Nematode
Fungus
and
and
and
Bacteria
Bacteria
Cercospora sp.
Choanephora cucurbitarum
Cladosporium colocasiae
Colletotrichum sp.
Hirschmanniella miticausa
Leptosphaerulina trifolii
Neojohnstonia colocasiae
Phyllosticta sp.
Phytophthora colocasiae
Thanatephorus cucumeris
Pythium spp.
Dasheen mosaic virus
Alomae & Bobone viruses
Fusarium solani
Periconia sp.
Meloidogyne sp.
Botrydiplodia theobromae
Chaetophoma sp
Rhizoctonia sp.
Athelia rolfsii
Erwinia carotovora sub sp.carotovora
Xanthomonas campestris pv. aracearum
69
Iron
mg
0.7
0.6
0.9
Zinc
mg
3.2
0.7
Taro blight (Phytophthora colocasiae)
This is a fungus disease that produces dead
spots on the leaves. Often the spots run down the leaf
in a line, and there is a yellow border around the spots.
The edge of the leaf away from the spot often dies.
Early in the morning a white fuzz can be seen on the
surface of the spots.
It is this disease that has caused so much
trouble in coastal taro growing areas like Manus and
Bougainville.
In most of the Highlands this disease does not
cause much trouble because the altitude and cool
temperature stop the disease spreading. Diseased
plants can be seen in lower villages (below 800 m).
Taro shothole (Phyllosticta colocasiae)
This is another fungus disease that looks quite
a lot like taro blight. It has round dead spots that have
a yellow ring around them. Often there is a hole in the
centre of the spot where the dead leaf tissue has fallen
out. There is no white fuzz like with taro blight.
This disease is commonly seen on taro plants
in the Southern Highlands. It never gets bad enough to
kill the leaves or the plant, but it does some damage.
Brown leaf spot (Cladosporium colocasiae)
Irregular but almost round reddish brown
blotches can often be seen on older taro leaves. They
are due to another fungus.
The spots don't seem to do a lot of damage to
the leaf and the growth of the plant does not seem to
be seriously affected. It gets worse in humid damp
conditions.
Leaf spot (Neojohnstonia colocasiae)
Yellow or brown spots round or irregular and
1.5 cm across occur on the leaves.
Leaf blight (Thanatephorus cucumeris)
Bacterial leaf spot
(Xanthomonas campestris)
Root rot
(Pythium sp. & Phytophthora sp.)
These rots of the corm and roots can cause
problems while taro is growing in moist areas. The
disease is reduced if healthy planting material is used,
diseased plants are removed, water does not become
stagnant around taro, and proper crop rotation is used.
Some varieties get less damage. Where soils are wet
or flooded, kinds of taro suited to these situations
should be used.
Dasheen mosaic virus
This disease often shows itself on taro leaves as
a fine feathery yellow and green streaking pattern
around the veins of the leaf. The leaves can also
become slightly wrinkled.
It is caused by a very small particle called a
virus. These viruses are spread between plants in the
mouthparts of small sap sucking insects such as
whitefly. They also are spread in the taro planting
material.
It does not get as serious as other virus diseases
of taro in coastal areas, but it can be seen in Highland
gardens.
Alomae & bobone viruses
These are serious virus diseases that make the
leaves of taro go small and wrinkled then the whole
plant can die.
In some areas on the coast it is causing serious
damage. The very small disease particles are spread
by insects but can also be in the planting material.
Some varieties of taro get these diseases badly and
others don't seem to get the disease too badly.
71
Storage of taro
Most taro tru will only store for one or two weeks after harvesting. This is because storage
rots due to fungi and bacteria cause the taro to rot. The main organisms causing rots in storage have
been identified as:
Botryodiplodia theobromae is a very common fungus that causes silvering of yam leaves,
root rots of peanuts and many other rots. With taro in storage it causes a spongy black rot.
Fusarium solani is another very common fungus that often causes plants to wilt. With taro
in storage it causes a dry rot sometimes called powdery grey rot.
and
Erwinia caratovora is a bacteria that rots the strengthening substance in plant cell walls
causing things like soft rot in marita and other plants.
INSECT PESTS
Taro insect pests
Taro beetles
Taro hornworm/hawkmoth
Taro leafhopper
Aibika leaf miner
Banana aphid
Cacao armyworm
Cacao looper
Cluster caterpillar
Corn earworm
Dermolepida beetles (Chafer beetles)
Melon aphid
Shot hole weevils
Sweet potato hawkmoth
Tobacco whitefly
Scarabaeidae (COL)
Scarabaeidae (COL)
Scarabaeidae (COL)
Scarabaeidae (COL)
Scarabaeidae (COL)
Scarabaeidae (COL)
Scarabaeidae (COL)
Sphingidae (LEP)
Delphacidae (HEM)
Delphacidae (HEM)
Delphacidae (HEM)
Gracillariidae (LEP)
Aphididae (HEM)
Noctuidae (LEP)
Geometridae (LEP)
Noctuidae (LEP)
Noctuidae (LEP)
Scarabaeidae (COL)
Scarabaeidae (COL)
Aphididae (HEM)
Curculionidae (COL)
Curculionidae (COL)
Curculionidae (COL)
Curculionidae (COL)
Sphingidae (LEP)
Aleyrodidae (HEM)
Lygaeidae (HEM)
Lygaeidae (HEM)
Acridiidae (ORTH)
Taro beetles
These black or brown beetles are 2-3 cm long and
seem to occur wherever taro is grown in Papua New
Guinea. Their front legs are specially adapted for digging
and they burrow under the plant eating the corm. The
larvae or grubs also live in the soil and eat taro. There are
several different kinds of taro beetle.
The only place where damage seems less is in very
damp sites. Taro beetles can also damage a number of
other plants.
Papuana biroi End.
Papuana huebneri Fairm.
Papuana japenensis Arrow
Papuana laevipennis
Papuana semistriata
Papuana trinodosa Prell.
Papuana woodlarkiana (Montr.)
Hippotion celerio (L.)
Tarophagus colocasiae
Tarophagus persephone
Tarophagus proserpina (Kirk)
Acrocercops sp.
Pentalonia nigronervosa Coq
Tiracola plagiata Walk
Ectropis bhurmitra Walker
Spodoptera litura (Fab)
Heliothis armiger Huebner
Dermolepida nigrum (Non f.)
Dermolepida noxium Britton
Aphis gossypii Glover
Oribius cinereus Mshl.
Oribius cruciatus Fst.
Oribius destructor Mshl.
Oribius inimicus Mshl
Agrius convolvuli L.
Bemisia tabaci (Guen.)
Astacops flavicollis Walk.
Astacops villicollis (Stal.)
Gesonula mundata sanguinolenta Kraus
Taro hawkmoth
This large green caterpillar can often be found
under the edge of a taro leaf eating the leaf. It has a pale
stripe along the side, 2 large "eye" spots and a long
pointed brown horn at the end.
Although it can be found in most taro gardens in
the Highlands it never seems to develop large numbers
except in dry areas. It can occur badly in some lowland
gardens in the dry season.
A similar hawkmoth caterpillar with a distinctive
striped pattern along its body can also be seen in some taro
gardens. This is the sweet potato hawkmoth.
These caterpillars are large and can easily be
caught and killed by hand.
Taro leafhoppers
(Tarophagus spp.)
Cluster caterpillar
(Spodoptera litura)
The caterpillars of this moth develop in large
numbers clustered together on the leaf surface. The most
practical method of control at village level is to collect the
caterpillars in a paper bag when they are newly hatched
and then to burn them.
Tobacco whitefly
(Bemisia tabaci)
This small sap sucking whitefly can spread
Dasheen mosaic virus.
73
Winged bean or asbin
Scientific name: Psophocarpus tetragonolobus
The plant
The winged bean is a climbing bean that produces pods with four wings along the side. This
is why it is called winged bean in English. Under the ground it produces a thickened root or tuber
that is eaten. This is where the Tok Pisin name asbin comes from. The seeds are round.
The two main types of winged bean are short-podded ones that are used for tubers and long
podded ones that have poor tubers. But a very large number of winged bean varieties occur in
Papua New Guinea.
What's so special about winged beans?
Winged beans have recently been “discovered” by scientists and other people around the
world. They have called it a plant with “exceptional merits”; a “miracle plant”; a “supermarket on a
stalk” and many other excited comments. The reasons for these comments are because winged
beans:
1. Grow well in the hot humid tropics.
2. Almost all parts of the plant can be eaten.
3. All parts of the plant have high food value, especially protein.
4. Winged beans generally suffer less from damage of bean insects, pests and diseases than
other beans.
5. They are very good at fixing nitrogen for their own growth as well as for other plants.
Where do winged beans grow?
In Papua New Guinea, winged beans are grown in many areas of the country. They can be
seen from sea level up to about 2300 m altitude although they are less common above 1850 metres
and normally only produce tubers between 1200 and 1850 m altitude. They are common in Sepik
areas in the lowlands and in the mid altitude highland regions especially the Eastern Highlands and
Western Highlands.
For maximum seed production winged beans need temperatures between 23° and 27°C and
for tubers the temperatures should be between 18° and 22°C.
Winged beans can only be grown in the tropics because flowers and seeds are not formed in
countries out of the tropics. But they are grown in a number of other tropical countries particularly
in the Asian region.
Winged beans can grow on a wide variety of soils. The acidity of soils is measured on a
scale from 0 to 14 and it is called the pH scale. Better soils are near neutral or 7. Winged beans
have been grown on soils with pH from 3.6 to 8.0. This is a wide range. When soils become very
acid, the aluminium that is common in clays in soil can get into solution and into plants.
Aluminium is not a plant nutrient and is not needed by plants. Winged beans are sensitive to
aluminium in soil solution.
Soils should not be waterlogged.
75
Growing winged beans
Seeds are planted 2-3 cm deep and about 25-35 cm apart. If seeds have been dried and
stored then they can suffer from hard seed coats and this delays the germination of seeds. But
normally seeds start to grow in about 15 or 16 days. Plants grow slowly to start with so weeding is
important but then they grow rapidly. After 46 to 92 days they are producing flowers. If fattened
roots are important some of the leaves and flowers and tips are pruned off at this stage. These can
be eaten. Pods develop 10 to 13 weeks after planting and tubers occur 4-5 months after planting.
For tubers, plants are planted at special times to allow them to develop during the dry
season.
Winged beans need to be staked for high yields. Stalks from pitpit are sufficient.
Winged
beans being
grown for
tubers
All beans have special bacteria (Rhizobia) that attach to the roots and enable beans to take
nitrogen out of the air and change it into nutrient nitrogen that plants can use. With winged beans
the lumps or nodules that contain these bacteria are very large, they form very easily even in soils
where beans haven't been grown before and they work very efficiently as well. They enable winged
beans to grow well, help them have a high protein content and can also help provide nitrogen in the
soil for other plants.
Root knot and nodules
How much food is produced?
Winged beans are mostly grown for their tubers, pods and leaves. Dry beans are not used a
lot in Papua New Guinea although firm mature beans are eaten fresh from cooked pods.
A single plant can produce up to 75 pods.
Dry bean yields of 45 to 330 g per plant can be produced depending on variety.
Tuber yields of 5500 to 12000 kg per hectare have been produced.
77
Winged beans as food
Seeds can contain a chemical (trypsin inhibitor) that stops the protein being properly
digested by our bodies. This chemical is destroyed if seeds are soaked then boiled well. Tubers can
also contain this chemical and need to be well cooked.
On of the main things about winged beans is that they are good at providing protein. The
protein content of the different parts varies between varieties but some of the amounts are indicated
below.
Plant part
Seeds
Fresh tubers
Fresh leaves
Fresh pods
Flowers
Protein (g per 100 g)
29.8 - 42.5
2.27 - 8.05
4.55 - 11.81
1.31 - 2.73
1.25 - 2.65
This means all parts of the winged bean plant are very good for providing protein. They are
also good sources of vitamins, minerals and energy.
Winged bean tubers are tied in bundles and sold in markets. They won't keep for very long
so need to be treated carefully and eaten quickly. In villages the most popular way to cook them is
in a mumu in an earth oven. They are dry and firm and very nice tasting.
The leaves and flowers are mostly boiled.
Although pods are often roasted then the beans just eaten from the pod as it is split open, the
beans have more food value if they are soaked then boiled.
Food value per 100 g edible portion
Edible portion
Moisture
%
Energy
KJ
Protein
%
Seed dry
Seeds - young
Pods fresh
Roots
Leaves
8.5
87.0
92.0
57.4
95.0
1764
205
105
619
197
41.9
7.0
2.1
11.6
5.0
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
13.0
Tr
18.3
15.0
1.5
0.4
0
809
0
30
2.0
6.2
1.4
1.3
What insects damage winged beans?
Bean fly (Ophiomya phaseoli)
The bean fly can burrow into the young stems of
seedling winged beans. This weakens the plants slowing
down growth and causing plants to fall over. They suffer
less of this damage than common bean.
Bean pod borer (Maruca testulalis)
The caterpillar of this moth is yellow with
brown or black spots along the body. They are thin
and up to 25 mm long. The moth lays eggs singly on
the flowers then the larvae bore into the young pods
leaving chewed up plant material over the hole
where they bored in.
Winged bean blotch miner (Leucoptera psophocarpella)
This small leaf miner can cause serious
damage in drier areas.
A number of other insects also damage winged beans.
Winged bean insect pests
Winged bean blotch miner
Amblypelta bugs
Bean leaf rollers
Bean pod borer
Cacao armyworm
Common grass blue butterfly
Cowpea aphid
Green Vegetable bug
Leaf eating ladybird
Melon aphid
Pea Blue butterfly
Grasshopper
Rice armyworms
Adults and nymphs feeding under
leaves
Larvae eating leaves
Grasshopper chewing leaves
Larvae damaging leaves
Beetles on pods
Beetles damaging dry pods
Cicada on leaves
Scale insect
Lyonetiidae (LEP)
Coreidae (HEM)
Pyralidae (LEP)
Pyralidae (LEP)
Pyralidae (LEP)
Noctuidae (LEP)
Lycaenidae (LEP)
Aphididae (HEM)
Pentatomidae (HEM)
Coccinellidae (COL)
Coccinellidae (COL)
Aphididae (HEM)
Lycaenidae (LEP)
Tettigoniidae (ORTH)
Noctuidae (LEP)
Noctuidae (LEP)
Anthribidae (COL)
Anthribidae (COL)
Cicadellidae (HEM)
Leucoptera psophocarpella Brad. & Cart.
Amblypelta spp.
Lamprosema indica F.
Lamprosema diemenalis (Guenee)
Maruca testulalis (Geyer)
Tiracola plagiata Walk
Zizina otis (F.)
Aphis craccivora Koch
Nezara viridula (Linnaeus)
Henosepilachna signatipennis Boisd.
Henosepilachna haemorrhoea (Biel)
Aphis gossypii Glover
Lampides boeticus L.
Phaneroptera brevis Aud.-Serv
Mythimna loreyi (Dup.)
Mythimna separata (Walk.)
Araecerus fasciculatus Degeer
Araeocorynus cumingi Jekel
Erythroneura sp.
Lymantriidae (LEP)
Gryllidae (ORTH)
Arctiidae (LEP)
Cerambycidae (COL)
Cerambycidae (COL)
Cicadellidae (HEM)
Pseudococcidae (HEM)
Euproctis sp.
Homeoxipha fuscipennis
Nyctemera baulus Boisduval
Prosoplus oblique plagiatus Breuning
Ropica honesta Pascoe
Zygina sp.
Planococcus pacificus Cox
79
What diseases does winged bean get?
Winged bean diseases
Flower blight
Anthracnose
Leaf spot
Collar rot
Sooty mould
Powdery mildew
Leaf spot
False rust
Leaf curl
Little leaf
Root knot
Fungus
Fungus
Fungus
Fungus
and
and
Fungus
Fungus
Fungus
Fungus
Possible virus
Possible mycoplasma like organism
Nematode
and
False rust (Synchytrium psophocarpi)
This light brown coloured fungus is well
known to most village winged bean growers. The
fungus can commonly be seen on pods and also grows
on the leaves, stems, and flower buds. It makes the
pods less attractive to eat. (Because fungi are often too
small to see, this fungus disease is often a good one to
use to teach people in villages about disease and what
fungi are.) The disease spreads with temperatures
between 10° and 25°C and when there is moisture on
the plant surface.
Leaf spot (Pseudocercospora psophocarpi)
This fungal leaf spot grows on the leaves. It
starts as small yellow spots on the top of the leaves
and it is grey to black underneath. The whole leaf can
become infected and die particularly ruing the rainy
season. All varieties of winged bean get the disease.
Powdery mildew (Erisyphe cichoracearum)
This fungus causes a disease that looks like a
white powder on the upper surface of the leaves. It
grows on older leaves and the leaves become pale then
die and fall off. It is most likely that this fungus is the
same one that grows on cucumbers.
Choanephora cucurbitarum
Colletotrichum lindemuthianum
Didymella sp.
Macrophomina phaseolina
Fusarium spp.
Thanatephorus cucumeris
Meliola erythrinae var psophocarpi
Oidium sp.
Pseudocercospora psophocarpi
Synchytrium psophocarpi
Meloidogyne incognita
Meloidogyne javanica
Collar rot (Macrophomina phaseolina, Rhizoctonia solani &
Fusarium spp.)
These fungi cause the roots to die or the stem
to die near the ground level. So the young plant (3 to 4
weeks old) is seen to wilt. If you look carefully the
stem is more narrow near the ground and black dead
spots occur on it. This disease can probably be
avoided by planting seeds more shallowly and in welldrained soils.
What other pests damage winged bean?
Root knot nematodes (Meloidogyne spp.)
These very small worms (too small to see
without special equipment) live in the soil and damage
the roots of many different plants. They burrow into
the roots and the damaged root becomes thick and
twisted and no longer works properly to provide
nutrients or water for the plant.
Root knot
With winged beans (and other beans) it is important to be able to tell the difference between this
root damage, and the good root tuber and the helpful bacteria that attach to the roots and help the
plant fix nitrogen. If you pull up a plant and look at the roots, the bacteria nodules are just on the
side of the roots (should be red inside if they are working properly) and can be pulled off the roots
without damaging the roots. Root knot nematode is a twisted damaged root and cannot be pulled
off. The asbin tuber is the developing fattened central root.
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Yams
Yam tru
Mami
Scientific names:
Dioscorea alata - Greater yam
Dioscorea bulbifera - Potato yam
Dioscorea pentaphylla - 5 leaflet yam
Dioscorea esculenta - Lesser yam
Dioscorea nummularia - Greater yam
Dioscorea rotundataFour species of yams are commonly grown and used for food in Papua New Guinea but often
naming in villages and naming by scientists does not agree. Many village people regard potato yam
and 5-leaflet yam as varieties of greater yam.
Tok Pisin:
Five leaflet yam
Bitter yam
What is a yam plant like?
All yams have long creeping vines that wind around sticks.
Greater yam
The greater yam has a stem with wings on the sides making it square in shape. The heart
shaped leaves are in pairs along the vine. Under the ground it normally produces one fairly large
tuber. These tubers can be many different shapes.
Some of the tuber shapes of Greater yam
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Greater yam has long angular vine. The stems are square and twine to the right around
support sticks. The stem does not have spines. It is often coloured green or purple. The leaves are
heart shaped and borne in pairs along the vine. The leaves vary is shape, size and colour with
different varieties. Leaves can be 10-30 cm long by 5-20 cm wide. The leaf stalk is 6-12 cm long.
The flowers occur in the axils of the upper leaves. The male flowers are in small heads along
branched stalks. These can be 25 cm long and green. The female flowers are in shorter spikes.
Many cultivated varieties do not produce fertile seed. The fruit are 3-winged and 2.5 cm long by
3.5 cm wide. The seeds when they occur have wings right around them. One large but often
irregular shaped tuber occurs under the ground. A very large number of different varieties occur.
The tubers can vary in shape, size, colour, texture and other ways. Some varieties produce bulbils
along the vine.
It grows from sea level up to about 1800 m in the tropics. Yams are most important in
seasonally dry areas. They need a well-drained soil and it has to have reasonable fertility. The
temperature maximum is >30°C while the minimum is 20°C. The optimum temperature range is
25-30°C. Rainfall is often seasonal in yam areas and the maximum to be needs 14-20 weeks rain
with an optimum of 1,150 mm during the growing season. Yams can tolerate drought but give
maximum yields with high rainfall. The critical rain period is during the first 5 months. Light
influences tuber growth. A continuous exposure of tubers to light significantly reduces tuber yields.
Day length - Yams are influenced by photoperiod. Short days (less than 10-11 hours) favours tuber
development. It suits hardiness zones 10-12.
In most places the yam growth and maturity fits in with seasonal rainfall patterns. They are mostly
planted just before the first rains where a 8-10 month rainy season exists and give better yields in 68 month rainy season areas when planted 3 months before the rains. Earlier planting requires larger
sett size to withstand drying out.
Pre germination of tubers that are cut and stored in shady places gives improved yields over tubers
left whole then cut into setts at planting. Because yam tubers have a period of dormancy, tubers do
not normally commence regrowth for up to 5-6 months. This means they store better but there is a
delay before they can be replanted. Dormancy can be broken using Calcium carbide treatment for 5
hours or by covering tubers with leaves of Croton aromaticus or Averrhoea bilimbi.
Yams are demanding in their nutrient requirements and are therefore often planted first in rotations.
They need a fertile free draining soil. They cannot tolerate water logging.
In drier grassland areas mulching the mounds at planting has been found to improve
establishment and yield.
In most places in Papua New Guinea the Greater yam is called yam tru in Tok Pisin. At
Madang and along the Sepik coast it is called mami.
It is not easy to know all the different varieties of yams but there are some rules that are
fairly often true. These rules can help a little bit to understand the types of yam tru.
Some guidelines about varieties of Greater yam
Yams that are red inside are normally red at the top of the stalk that holds the leaf.
Plants with a number of stems near the ground often have tubers that are branched. They
sprout more easily.
The more the young stem branches, the less deep the tubers are in the ground.
Leaves that are fatter and shorter indicate fatter yams, often angular in shape and with
surface roots.
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Lesser yam
The Lesser yam is called mami in Tok Pisin in most areas of Papua New Guinea except
Madang and the Sepik coast. It has a round thorny vine and a smaller more rounded leaf. The
leaves are borne singly along the vine. Under the ground there are a clump of tubers. But there are
also some very sharp thorns just under the ground, so be careful! The tubers again vary in shape,
size and colour. One of the most noticeable differences between kinds is the amount of roots or
hairs over the surface of the tubers.
Some of the tuber shapes of Lesser yam
These are some
of the kinds from
Dreikiker at
East Sepik.
They were
described by
Dr.B.Allen at
the 1981 Food
Crops
Conference.
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Potato yam
This yam has a very long smooth vine that often climbs up trees especially near where the
grassland and forest meet. Along the stem it produces round or lumpy potato like aerial tubers.
(bulbils) They are in a branch where a leaf stalk joins the stem. There is also a tuber under the
ground. Some people eat the aerial tuber and plant the tuber that is under the ground. Other people
eat the underground tuber and plant the aerial tubers. This may depend on varieties.
Five leaflet yam
This yam has a leaf that is divided like the fingers on your hand. The number of leaflets can
vary between 3 and 7 but there are mostly five. The leaves look a bit like cassava but they grow on
a long vine that winds up a stick. There are also wild types that grow in the bush. This yam often
has small aerial tubers (bulbils) along the vine.
Where do yams grow?
Most yams are truly tropical plants so they grow better in coastal areas. Also yams are well
suited to growing in areas where there is a distinct wet and dry season. The pattern of growth of
yams suits these climates. They can grow lots of leaves at the beginning of the wet season, store up
food in the tubers as the leaves dry off with the approach of the dry season then the yams can be
stored during the dry period.
Yam
Greater yam
Lesser yam
Potato yam
Five leaflet yam
Altitude above sea level
0-1650 metres
0-800 metres
0-1700 metres
0-1800 metres
Some of the places in Papua New Guinea where yams are important include Maprik in East
Sepik; the Eastern Highlands; near Port Moresby; the Trobriands in Milne Bay; and Morehead in
Western Province.
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Around the world there are about 10 million tons of Greater yam grown each year in hot
tropical countries. Practically all of these are grown in subsistence gardens similar to those in
Papua New Guinea.
A man who collected Lesser yams from many different countries of the world found that the
kinds of Lesser yams in Papua New Guinea were the best in the world.
How do you grow yams?
Yams are normally grown from tubers. With Lesser yam, one of the smaller tubers is often
planted whole. With greater yam, any reasonable sized part of the tuber can be planted. Mostly the
top piece is used because it produces new shoots the quickest and will grow the biggest tuber by
harvest. But if a middle piece or a bottom piece of the tuber is cut off and stored carefully it too
will produce new shoots and can be planted. Greater yam, potato yam and five-leaflet yam all
sometimes produce aerial bulbils along the vine. These can be used for planting but do not always
produce a big underground tuber in the first year.
A sprouting lesser yam
A top piece of greater yam
Although many yams often produce long flowers and both male and female flowers can be
found on separate plants, these hardly ever produce true seeds that will grow. This is because of the
different number of chromosomes that yams have and it makes yam breeding almost impossible.
A male flower of Greater yam
Planting practices
It is common practice in many areas to plant the yam piece upside down. The probable
reason for this is to give the shoot and roots time to develop and get established away from the sun
and wind, so that the plant does not dry out. People in yam areas have their varieties classified as to
whether they are planted at the top or the bottom of the hole, and whether the shoot is pointed up or
downwards. The reasons for this are not fully understood but village people have probably learnt
by experience.
Yams must have a well-drained soil with plenty of air in the soil. So yams will not normally
grow on heavy clay soils or in areas with a lot of soil moisture. The soil can be improved for yam
growing by putting leaves and other plant material in the planting hole, by making a mound above
the hole, or by planting on a hillside. In some very loose sandy soils such as near Port Moresby
yams can just be planted in flat unmounded soils without digging a special yam hole but these
situations are not common.
Yams should also have sticks to climb up. It is best to have a stick that is twisted or
branched because the vine can slip down a very straight stick. Normally a stick 2 metres tall is
sufficient. It needs to be a strong stick, firmly fixed in the ground. Yam varieties vary on the type
of vine growth they have. This affects where the stick needs to be placed.
A broad irregular shaped
yam tuber often has several
branches and grows leaves
early
A long straight yam tuber often
has a long unbranched vine
with few leaves on the bottom
section
The fat irregular yams can have the sticks near the mound as a thick clump of vines and
leaves soon develops. But if the stick is put beside the mound of one of the long ceremonial yams
the vine will often reach the top of the stick before it has produced more than a couple of leaves,
and will then fall back down to produce its leaves on the ground. The stick often needs to be put at
some distance from the yam hole. The tip can be picked off the vine if branching is wanted earlier.
It may be that the long vine yams are more common in forest areas and the shorter branched
vines in grassland areas.
In some areas yam vines are allowed to creep over the ground and do not have sticks to
climb. This method only works satisfactorily in dry places like the Markhum Valley and Central
District because diseases of the leaves and vine can cause serious damage in wetter places. Where
yams do not have sticks to climb plants need to be more widely spaced. Under most circumstances
the amount of food produced can be doubled by allowing yam vines to climb up sticks.
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Potato yam vines are very long and heavy and it is often most easy to allow them to climb
over logs or up trees.
A long ceremonial yam tied to a stick
People in the Sepik area grow some of the largest yams in the world. They do this by
putting together all the important principles of yam growing.
The method used by
Sepik people to grow
large ceremonial yams
Ceremonial yams have very specialised production techniques. For general food production, use
top pieces of the tuber after they have sprouted, use a branched stick for support of the vine, space
plants about 1 m apart and choose a smooth round cultivar. Given the large diversity of cultivars of
greater yam, for efficient production varieties need to be chosen which have regular rounded tuber
shapes for easier harvesting and preparation; also selection needs to be made for varieties with less
leaf spot and virus susceptibility and stable yield. Colour, cooking quality, storage ability, texture
and other qualities need to be considered to suit the growers demands.
Pest and disease problems
The diseases of yams have not been well studied and are not well understood. Diseases on
the leaves can be seen in almost all yam gardens and on all kinds of yams. Village people don't
understand about disease so say the leaves died off early because of "fire" or lightning, or because
garden taboos were broken.
The diseases that have been listed so far include:
Five leaflet yam
Leaf spot
Rust
Fungus
Uredo dioscoreae-sativae
Fungus
Fungus
Fungi
and
and
Glomerella cingulata
Phyllosticta dioscoreae
Goplana dioscoreae
Goplana australis
Uredo dioscoreae-sativae
Mosaic
Root knot
Nematode
Meloidogyne sp
Lesser yam
Leaf spot
Leaf spot
Dark brown leaf blotch
Mosaic
Root knot
Fungus
Fungus
Bacteria
Perhaps virus
Nematode
Cylindrosporium dioscoreae
Guignardia dioscoreae
Xanthomonas sp.
Potato yam
Brown mould under leaf
Rust
Fungus
Fungus
Pseudocercospora ubi
Uredo dioscorae-sativae
Greater yam
Anthracnose
Leaf spot
Rust
Also general or non specific on "yams"
Leaf spot
Fungus
Dry rot
Fungus
Collar rot
Fungus
and
and
With tuber rot
Fungus
Leaf spot
Fungus
Necrosis of tubers
Nematode
Meloidogyne incognita
Curvularia sp.
Fusarium sp.
Fusarium oxysporium
Penicillium funiculosum
Penicillium javanicum
Scutelina badio-berbis
Mycosphaerella contraria
Pratylenchus sp
Anthracnose is caused by a common fungus and starts as spots but leaves and vines soon
blacken and fall off. Phyllosticta leaf spot has a dark brown ring around a light brown spot and
often there is a hole in the centre. Cercospora leaf spots tend to have a yellow ring around a brown
dead spot.
These leaf spot diseases get worse in wet weather and under poor growing conditions. They
often start on older leaves but can then spread to younger leaves and vines. There is a lot of
obvious difference in the level of resistance to these diseases between the yam species and varieties.
In some areas of Papua New Guinea yam leaves develop mottled yellow patterns on the
leaves and the vines stop growing. This disease is due to a virus.
93
Silvering of yam leaves. This can be due to a fungus called Botryodiplodia theobromae
that is a very common fungus in Papua New Guinea and gets on many different plants. With
greater yam the leaves start to develop a silvery colour and start dying off early. This fungus gets
bad in coastal areas where temperatures are about 30°C and when yams are not growing well.
Root rots of yams have also not been well studied in Papua New Guinea. Rotting of yam
tubers either in the ground or in storage can occur due to a fungus that is common in Papua New
Guinea (Botryodiplodia theobromae). It can cause wet rot, soft rot and brown dry rot. Handling
tubers very carefully is important in stopping this disease.
Phyllosticta leafspot Lesser yam
Anthracnose Greater yam
Rust of Potato yam
Insects on yams
Sawfly
Yam sawfly
Tenthredinidae (HYM)
Sap sucking bugs
Cotton aphid
Black leaf-footed bug
Yam mirid sapsucker
Senoclida purpurata (F.Sm.)
Aphididae (HEM)
Miridae (HEM)
Aphis gossypii Glover
Harpedona plana Poppius
Coreidae (HEM)
Miridae (HEM)
Leptoglossus australis (Fab.)
Platypeltocoris similis Popp
Curculionidae (COL)
Alcidodes australis Boisduval
Curculionidae (COL)
Curculionidae (COL)
Eupholus nickerli Hll.
Gymnopholus weiskei Hllr.
Curculionidae (COL)
Crioceridae (COL)
Crioceridae (COL)
Hypolixus mastersi Pascoe
Liliocerus sp nr. bakewelli Baly
Liliocerus papuana (Jac.)
Curculionidae (COL)
Papuana spp.
Nymphs and adults reported
damaging greater yam leaves and
some varieties suffered severe
damage. The leaves go spotted
with light patches.
Weevils or beetles
Taro beetles
Reported causing minor damage to
yam leaves.
Reported damaging yam. See PNG
Ag J 18(3)
Reported damaging yam
Reported adults and larvae
chewing leaves of greater yam.
Larvae of moths or butterflies
Yam hawkmoth
Geometridae (LEP)
Hesperiidae (LEP)
Chrysodeixis chalcites Esp.
Hyposidra talaca
Tagiades obscurus tindali Rbb
Hesperiidae (LEP)
Hesperiidae (LEP)
Sphingidae (LEP)
Tagiades tregellius Hopf.
Tagiades tregellius canonicus
Theretra nessus Dry.
Eating lesser yam leaves
Eating leaves of yam.
Larvae feed on yam leaves
throughout the year. PNG Ag J
21(7). Only slight damage
Larvae rolling leaves
Eating leaves of yam
Armoured scales
Abgrallaspis cyanophylli (Signoret)
Aspidiella hartii (Cockerell)
On greater yam.
On yams in storage. It can be
on greater or lesser yam.
Aspidiotus destructor Signoret
Soft scales
Icerya seychellarum (Westwood)
Coccus hesperidium Linnaeus
Mealybug
Yam mealy bug
Planococcus pacificus Cox
Planococcus dioscoreae Williams
Yam hawkmoth
The larvae of a hawkmoth can be seen eating
leaves in some yam gardens. It is a caterpillar with a long
point on the end and it looks a bit like similar ones that are
more commonly seen eating taro and sweet potato leaves.
This one forms a pupae case in amongst the yam leaves
and eventually hatches out to a moth.
Rats
Rats can be a big problem with stored yams unless the yams are well looked after.
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Polynesian arrowroot
Scientific name: Tacca leontopetaloides
What is the plant like?
Under the ground there is a round swollen root or tuber. It can be 30 cm across and weigh 1
kg. Some varieties produce several smaller tubers.
The stem is hollow, and ribbed. This is one way to tell this plant from the somewhat similar
looking leaf of Elephant foot yam. The leaf petiole is about 2 cm across and over one metre long.
The leaves have an irregular shape and are divided. The main part of the leaf is divided like
the fingers on your hand and then these are again divided. They have light and dark green stripes.
There are fine grooves along the leaf stalk.
A single flower stem grows up beside the leaf stem. On the top the flowers are green and a
dull dark purple. There can be 30-40 small flowers and several long spreading and drooping
coloured bracts. Flowers and fruits are produced throughout the year.
The fruits are yellowish green, long shaped and with 6 raised lines along the side. They can
be 4 cm long and 2 cm wide and have several seeds inside.
Where is Polynesian arrowroot grown?
It is a crop mainly grown in tropical Asia and Polynesia. It is also grow in East Africa.
It is a coastal crop and is mostly grown on sandy beaches under coconuts and in grassland.
It is grow on coral atolls. It is grown up to about 200 m altitude.
How does arrowroot grow?
Polynesian arrowroot is a plant that grows during the wet season and dries during the dry
season.
When the leaves turn yellow and the plant dies back, the tubers are harvested. Small tubers
are kept for replanting. Dying off mostly occurs from December to March. Plants take about 8 to
10 months to reach maturity.
Names
The common English name for this plant is Polynesian arrowroot but also Tahitian
arrowroot and East Indian arrowroot. There are other arrowroot plants that must not be mixed up
with this one.
The scientific name is Tacca leontopetaloides. A Dutch scientist called Rumphius worked
in the Moluccas in Indonesia just West of New Guinea and he described Tacca plants in the year
1747. He used the word tacca from the local Malay language. In 1930 world scientists agreed that
the other part of the name, leontopetaloides, was to replace the older name Tacca pinnatifida.
How is Polynesian arrowroot used?
The starchy tuber is eaten. Normally the tuber is scraped into small shreds and then washed
in water. The starch is filtered out and allowed to settle. The starch is washed several times to get
rid of bitterness that is common with this plant.
To get clean white starch, the tubers need to be carefully peeled.
The starch can be hung in a cloth to allow the water to drain and then it can be sun-dried.
Once dry, the fine powdered arrowroot starch will store well in a sealed jar. The starch is tasteless.
The leaves have been recorded as eaten in Africa.
The yellow fruit is also eaten by children in some places.
Diseases
A leaf spot due to a fungus occurs on leaves of Polynesian arrowroot. The fungus is called
Cercospora taccae. Mostly these fungal spots have a yellow ring around a brown dead spot.
Insect pests
Soft scale
Margarodidae (HEM)
Icerya seychellarum (Westwood)
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Queensland arrowroot
Names:
Scientific name: Canna edulis
What is the plant like?
This is a broad-leafed plant with purple leaf sheaths where the leaf clasps the stem and the
large leaves have a brownish purple edge. It can grow up to 2 metres high.
Under the ground it has a large lumpy root like stem that is fleshy and purple. There is a
clump of these corms and they are surrounded by leaf scars. New suckers and roots grow out from
near these scars. A clump of shoots can occur for one plant.
The flowers develop on a stalk above the leaves and are small and dark red.
Where is it grown?
This arrowroot is mainly grown along the Papuan side and in Central and Milne Bay
Provinces and around Port Moresby. It is commonly seen in the Koki and other markets around Port
Moresby. It can be grown up to 1600 metres altitude. It can stand some shade but needs a heavy
fertile soil to produce well.
How is it used?
The rhizomes are eaten after baking. The tubers can be grated then the starch removed by
washing and straining. The leaves can be fed to animals.
Planting
Pieces of the rhizome are used for planting. A spacing of about 1 metre apart is suitable. It
can be harvested after about 6-8 months.
Fongaar
Scientific name: Ipomoea macrantha
Synonum: Ipomoea tuba
Where did the name come from?
This root crop is grown in the Morehead area south of the River Fly. People in that area
treat it as if it is another variety of yam. It is not a yam but a plant in the sweet potato family. It has
a number of different names in Tok Ples. These include:
Name
Hangaar
Fongaar
Tok Ples
Arufe
Kondobl
Scientists have given this plant the name Ipomoea macrantha
What is the plant like?
The plant has a long angular vine 5 to 6 metres long and it climbs up stakes. The leaves are
almost round and are produced singly along the vine. Flowers are somewhat like sweet potato
flowers and are produced at the top of the vine. Under the ground it produces a group of large
fleshy roots shaped like cassava roots. These are harvested after the vine and leaves die back. The
flesh inside the root is white. There is slight variation in the plant with both long and more rounded
tubers. There is also some variation in leaf shape.
In some places the plant grows wild and is not eaten.
99
How is it grown?
People plant a section of the top of the fattened root which first grows vines and leaves, then
the thickened storage organ is produced. The planting time depends on rains. In the Morehead area
they can be planted in November if the rains come but are otherwise planted in December. They
can be ready for harvest by July at the earliest and more commonly in September. So they take 7 9 months to grow to maturity.
Other parts of the fattened root can be used for planting.
The root can be stored for some time after harvest and this is normally done along with
yams in the yam houses. They can be stored for 4 to 5 months.
Flowers
How is it used?
The roots are simply roasted and eaten in the same way as yams.
The thickened roots can be up to 65 cm long and 12 cm wide. They can weigh up to 2.5 kg.
Pests and diseases
These have not been studied. An obvious leaf spot occurs on the leaves. This is most likely
due to a fungus.
Edible leafy greens
Aibika
Amaranth
Blackberried nightshade
Ferns
Climbing swamp fern
Tree ferns
Diplazium
Kumugras
Waterfern
Fig leaves
Ficus pungens
Ficus copiosa
Kangkong
Kalava (Ormocarpum)
Rungia
Dicliptera papuana
Tu-lip
Valanguar
Watercress
Rorippa
Water dropwort (Oenanthe)
Waterleaf
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Edible leaves
Many plants have leaves that are edible and are of high nutritional value. This includes many plants
that are grown for other reasons. Here is a list:
Sweet potato
Swamp taro
Cassava
Peanut
Snake bean
Lima bean
Jack bean
Rice bean
Highlands kapiak
Desmodium microphyllum
Cucumber
Snake gourd
Bitter cucumber
Swede
Kohl rabi
Radish
Capsicum leaves
Beetroot leaves
Rukam leaves
Mulberry leaves
Taro tru
Giant taro
Breadfruit leaves
Winged bean
Cowpea
Common bean
Mung bean
Velvet bean
Chilli
Nettles
Pumpkin
Bottle gourd
Smooth loofah
Brussels sprouts
Broccoli
Japanese radish
Hibiscus leaves
Golden apple leaves
Durian leaves
Indian mulberry leaves
Chinese taro
Elephant foot yam
Jackfruit leaves
Lablab bean
Pigeon pea
Pea
Green gram bean
Broad bean
Wandering Jew
Choko
Marrow
Wax gourd
Angled loofah
Cauliflower
Turnip
Celery leaves
Carrot leaves
Coffee plum leaves
Rosella leaves
Some guidelines for edible green leaves
It is my impression that people in Papua New Guinea experiment with different leaves to see
if they are edible and nice tasting. For example, in some areas people have tried eating European
potato leaves and still at times eat the young leaves. These are poisonous due to a chemical called
solanin and should not be eaten. So leaves can contain poisons and this needs to be thought about
before leaves are eaten. Three types of poisons often occur in leaves. These are cyanide, oxalates
and alkaloids. Cyanide is common in many plants especially on the tropics because it is made up of
three simple things hydrogen, carbon and nitrogen, that occur in all plants. Cyanide is bitter, so if
leaves or other plants have an unusual bitter taste it is good to be careful. But cyanide very easily
gets destroyed on heating and cooking, so as long as most foods are well cooked, this poison does
not cause much trouble. Many wild cassava plants, for example have high levels of cyanide and
people know these are bitter and poisonous. Oxalates burn your throat. This effect is commonly
known from taro family plants. Some kinds are worse than others. Leaves that burn the throat
should be avoided. Alkaloids are less easy to detect without a chemical test. Plants and leaves
known to have high levels of alkaloids should be avoided. Some wild yams have high levels of
these chemicals.
103
Aibika
Okra
Amaranth
Basella
Chilli
Waterleaf
Rungia
Kangkong
Aibika
Tok Pisin: Aibika
Scientific name: Hibiscus manihot L.
The aibika plant
The aibika plant is a shrubby plant that can grow up to 1.5 or 2 metres tall. The leaves are
large and can vary in shape. The bush produces a number of branches and when it is old it
sometimes produces yellow hibiscus type flowers and seedpods. The stalks can be green or have
red colours on them. Normally the leaves are very dark green, but occasionally pale green types
occur.
105
Where is aibika grown?
Aibika is very common and popular in Papua New Guinea. It is also grown in a number of
the island countries of the Pacific, and in Indonesia. It is a plant well suited to hot tropical
countries. In Papua New Guinea it grows quickly and easily in coastal areas, but grows more slowly
in the highlands. Above 1800 metres altitude above sea level, it only grows poorly and is often
eaten by insects as fast as it grows.
Different kinds of aibika
Aibika plants vary in the shape of the leaves and in the amount of red colouring on the stalks
and leaves.
Some of the leaf shapes look like this:
The narrow leafed types tend to compete less well with weeds. In some areas people tend to
put the narrow leafed types in the middle of the garden, intercropped with kaukau, and the broad
leafed kinds near stumps or logs and around the edges of gardens. The pale green leafed kinds that
occur only grow very slowly.
How do you grow aibika?
Aibika is normally grown from cuttings. Lengths of about 25 cm (2 or 3 leaf joints or
"nodes") of fresh green stem cuttings are used. These are simply stuck in the ground.
A fertile soil is needed. Therefore aibika can be planted in good soil in a newly cleared
garden site, or it can be planted near houses where the soil fertility can be built up by adding scraps
and compost and ashes.
The growth and colour of aibika leaves can be improved greatly by spraying the leaves each
2 or 3 weeks with a very small amount of the nitrogen fertiliser called urea, dissolved in water. (A
0.5% solution). This uses less fertiliser than putting it on the ground where it can wash away in the
rain.
Picking out the tips of branches of aibika plants encourages the plant to produce more
branches and therefore more leaves. But when you are harvesting leaves, you should not pick too
many off the one bush at the one time. This is because it slows down the growth of more leaves.
If the soil is very fertile, older bushes, which are only growing a few leaves, can be chopped
off. The stump left in the ground can then re-grow into a new bush.
What insects damage aibika?
As aibika is such a nice food, it is not surprising that quite a few insects also enjoy it!
Many are pests of cotton as well.
Aibika insect pests
The insects damaging aibika can be sorted into 3 groups
1. Leaf chewing insects
Cluster caterpillar
Noctuidae (LEP)
Cotton leaf roller
Pyralidae (LEP)
Cotton semi-looper
Noctuidae (LEP)
Horned weevil
Curculionidae (COL)
Leaf beetles
Galerucidae (COL)
Shot hole weevil
Curculionidae (COL)
Small black flea beetle
Chrysomelidae (COL)
Giant grasshopper
Acrididae (ORTH)
Short horn grasshopper
Tettigoniidae (ORTH)
Tortoise beetle
Cassididae (COL)
A ladybird beetle
Coccinellidae (COL)
2. Stem & leaf boring insects
Aibika shoot boring grub
Noctuidae (LEP)
Aibika leaf miner
Gracillariidae (LEP)
A stem boring beetle
Languridae (COL)
A stem boring beetle
Cerambycidae (COL)
3. Sap suckers
Tip wilt bugs
Coreidae (HEM)
Nigra scale
Coccidae (HEM)
Cotton aphid
Aphididae (HEM)
A small flatid
Flatidae (HOM)
Indian cotton jassid
Cicadellidae (HEM)
Red cotton bug
Pyrrhocoridae (HEM)
A small leaf hopper
Riconiidae
Hibiscus mealy bug
Pseudococcidae (HEM)
Armoured scale
Diaspididae (HEM)
White scale
Coccidae (HEM)
Aphids
Spodoptera litura
Sylepta derogata
Anomis flava
Apirocalus ebrius
Cassena spp.
Oribius spp.
Nisotra spp.
Valanga irregularis
Phaneroptera brevis
Aspidomorpha australasiae
Epilachna signatipennis
Earias vitella
Acrocercops sp.
Anadastus albertisi
Glenea aluensis
Amblypelta spp.
Parasaissetia nigra
Aphis gossypii
Colgar tricolor
Amrasca devastans
Dysdercus cingulatus
Euricania discigutta
Maconellicoccus hirsutus
Unaspis citri
Pseudaulacaspis pentagona
Nisotra
Caterpillar
Scale
107
The most common insect, which can almost always
be found on aibika in the highlands, is the small shiny
black flea beetle. (Arsipoda tenimberensis). It jumps
when it is disturbed and chews small round holes in the
leaves.
In the Highlands, small grey long nosed weevils
(Oribius spp.) also commonly chew irregular shaped holes
in the leaves.
Because aibika is related to cotton, three similar
moths have grubs which damage both cotton and aibika.
These are the cotton looper, cluster caterpillar and the
cotton leaf roller. The grubs of the first one move by
forming loops, the grubs of the second one group together
in clusters, and the grubs of the third one roll the leaf by
turning it downwards. They all chew leaves.
The aibika shoot boring grub (Earias sp.) is the
grub of another similar moth. The moth lays eggs on the
young parts of the plants and then when the grubs hatch
they burrow into the stem.
The nigra scale is a small black scale like insect
that gets on the top stems of the plant. It sucks sap
weakening the plant. The hibiscus mealy bug has a white
floury type growth over the insect. It gets on the stems,
sucks the sap and can weaken plants.
How do you control the insect damage?
One simple sensible way to make the damage due to insects less serious, is to grow the
plants as well as possible so that the plant grows faster than the insects damage it. Remember
aibika likes warm places and fertile soil. On the coast it is easily possible to get aibika to grow
quickly but in the highlands insects can eat aibika as fast as it grows.
Oribius weevils are hard to kill with chemicals, but they can be caught and drowned in a tin
of water which has a little kerosene on the top. As these insects breed slowly taking about one year
for their life cycle, they can't breed up very quickly.
There are over 20 different kinds of aibika in Papua New Guinea and they all don't suffer
the same amount of insect damage. So it is possible to pick out kinds that will be less damaged.
Chemicals to kill insects can be used but as they will also kill people, they are dangerous.
The chemical called carbaryl will kill larvae of cotton aphid, aibika shoot boring grub, cluster
caterpillar and probably cotton looper and cotton leaf roller. But before you use chemicals you must
know a lot about them and how to use them. Also you mustn't eat any leaves for 7 days after
spraying. It may be as simple, and safer, to pick the grubs off the plants.
What diseases does aibika get?
Aibika doesn't suffer from a lot of diseases. It can get a leaf spot due to a fungus, and it can
get a white powdery mildew, also due to a fungus. But these don't seem to cause too much trouble
and are not often seen. Sometimes the leaves get an irregular pattern of pale yellow patches
amongst the green colour of the leaf. This is due to a virus but it does not seem to stop the growth
very much. Cuttings rot off near ground level particularly if they are in wet ground. This is
probably due to bacteria and fungi in the soil. In villages people plant a few extra plants to allow
for this type of problem.
Leafspot
Collar rot
Other pests
On coastal areas near the main towns the giant African snail badly eats aibika. It is not
known in the Highlands Provinces and would only survive in lowland areas. The Giant African
snail causes very serious damage when it newly arrives in an area, but gradually over a year or two
it causes less damage as things which control its numbers gradually start to breed up and restrict it.
It can be controlled by poison bates and can also be restricted by methods like digging straight sided
ditches around garden beds to keep it out.
Harvesting and using aibika
The young leaves and shoots are picked. They can be boiled, steamed or fried. Cooked
aibika leaves can be very slimy. If it is preferred to have them less slimy, they need to be steamed,
such as in bamboo, or fried.
The food value of aibika
Aibika is a very good quality edible green. Not only does it have high amounts of protein,
minerals and vitamins, the protein and energy proportions are in a good ratio. This means that it is
balanced in a way that makes it easy for the body to use it efficiently.
109
In a 100 gram portion of the leaves that are eaten, there are the following amounts of the
different types of food nutrients.
Moisture Energy
%
cals
Leaves
47-103
/ 100 g edible portion
Protein Calcium proVitA
g
mg
!g
2.6-5.7
580
90
provitC
mg
118
Iron
mg
3
Zinc
mg
How much food is produced?
At the University of Papua New Guinea at Port Moresby, Dr Kesavan has measured yields
of leaves of about 7 tons over an area of one hectare for one crop. This would be equal to
harvesting 7 kg of leaves from a plot 10 square metres in size.
Amaranth
Tok Pisin: kumu, sometimes aupa
Scientific names:
Amaranthus caudatus L.
Amaranthus cruentus L.
Amaranthus dubius Thell
Amaranthus tricolor L.
Amaranthus lividus L.
Amaranthus viridus L.
The amaranthus plant
These plants are very quick growing leafy plants that grow in many countries of the world
but are particularly suited to tropical countries.
They are mostly grown from seeds and the leaves either cut or the whole plant pulled up,
then cooked and eaten.
Different species are used and these are often suited to particular places and climates. Weed
species also occur which are not normally used for food.
The colouring of the leaves varies and they can be green, or have red and sometimes yellow
colours.
In some countries the seeds of some kinds are eaten as a grain.
111
These two species seem to be the most important in the Highlands.
Amaranthus cruentus
This one is often green and
is more common in the
higher areas.
It can be other colours on
the leaves. Completely blue
coloured kinds occur.
Amaranthus tricolor
This one often has a red
coloured mark in the centre
of the leaf.
It tends to be more common
in lower areas but is being
introduced into higher
places.
Where are amaranths grown?
Most people in most villages of Papua New Guinea grow and use amaranths. This is
equally true in the Highlands Provinces. Amaranths are also grown and used in most countries of
the tropical world. The map below shows some of the places where amaranths are important food.
Map from Grubben Amaranths
Kinds of Amaranth
Village people can recognise the variety of amaranth that is commonest in their particular
area. But different kinds of amaranths are being taken to different areas of Papua New Guinea. In
the Southern Highlands people seem to have swapped their kinds of amaranth. At Erave, the people
say that their traditional kind of amaranth is the one scientists call Amaranthus tricolor, and that the
other one (Amaranthus cruentus) is introduced. In the Mendi area people say exactly the opposite
about the same two plants.
There are some differences in appearance between the kinds of amaranth. Often the colour
or shape of the leaves gives some idea, but it is not always accurate. If you want to be sure about
the different species you need to look carefully with a hand lens. These female flowers towards the
bottom of the flower head are different.
A cruentus
A tricolor
A dubius
113
A caudatus
The kinds of amaranths don't seem to cross-breed much with each other so that each kind
remains fairly true to its original type. (They may have crossbred in the past to produce the different
types.) So each kind in each area seems to remain much the same. Different ones have probably
been brought in from other places. Also differences may be due to how they are grown.
How do you grow amaranths?
Amaranths are mostly grown from seeds. Sometimes people in the Highlands grow them
from cuttings. The seeds are collected from a mature dry seed head of an old plant. In the
Highlands, people often just store these dry flower stalks in their houses and then rub the flowers
between their hands over the place where they want the plants to grow. This method is very simple
and works alright. If you want to collect the seeds it is fairly easy. The flower heads can be banged
on a mat or piece of cloth. Then the rubbish can be blown out of this mixture by dropping it and
blowing gently as it falls.
Amaranthus seeds are very small. A thousand seeds weigh about 0.3 g. It is very difficult
to sow such small seeds evenly over the ground. So there are a few different methods you can use
to try and get the plants well spaced. One way is to mix the seeds with some sand and then when
you sprinkle this along a row it will only contain a few seeds among the sand. The other way is to
throw the seeds over a small plot of ground that will be a nursery. After 2 or 3 weeks the seedlings
can be transplanted into the garden bed where they are to grow. If the seeds are just scattered over
the garden, the small seedlings can be thinned out and either eaten of transplanted to a different
spot.
It is important to be able to recognise an amaranth seedling when it is small. This is
necessary so that it is not pulled out during weeding.
Seedlings look like this:
Seedlings are transplanted when about 5-7 cm tall.
What conditions do amaranth need to grow well?
Amaranths are tropical plants and like hot weather. Normally the hotter it is the better they
grow.
They also like plenty of sunlight. Do not plant them in places where they will be shaded.
The more sunlight the better they grow.
They need to have water most of the time they are growing. In areas with a high rainfall this
is mostly not a big problem.
The soil must be fertile. If they are put in an old garden they will only grow very poorly. So
you can either put them in a new garden site when it is cleared from bush, or you can build up the
old ground by adding compost. The small gardens close to a house can often be built up to a good
fertility by using the scraps and ashes and things that are left over near houses. Amaranths need
high amounts of two special nutrients. These are nitrogen and potash. The ashes from fires are high
in potash and that is probably why people in the Highlands have learnt by experience to scatter
seeds of amaranth over areas where they have burnt.
For amaranth seeds to germinate they need a temperature above 15°-17°C. In the higher
areas of the Highlands above 1800 m., temperatures on the average are probably below this during
the months of June, July, August and September. It may be more difficult to get amaranthus started
during these months although this has not been studied.
Plant spacing
In other countries a spacing of about 8 cm x 8 cm is used if the plants are to be harvested by
pulling up the whole plant. If the harvesting is to be done by picking off the top leaves, a wider
spacing is normally used. When the tops are picked out 3 or 4 times over the life of the one plant, a
spacing about 30 cm x 30 cm is used.
As far as producing a large amount of food is concerned, the spacing is not very important.
Having between 200 and 1,000 plants on each square metre gives about the same total amount of
food. The main thing that varies is the size of the leaves. Mostly people like larger leaves so a
wider spacing of 8 cm to 10 cm for plants to be pulled out is suitable.
For plants to be harvested by picking out the tops, they can be picked down to about 15 cm
high. Picking lower makes the plant flower later, but it also recovers more slowly from picking.
What is the growth of amaranth like?
Amaranths grow quickly. Seedlings come up above the ground in 3 to 5 days. They are 5 to
7 cm high and big enough for transplanting after about 20 days. The plants can be pulled out and
used after 6 weeks. If they are harvested by picking out the tops, this can be started at 5 to 7 weeks
and continued 3 or 4 times over the next 2 months.
Amaranths eventually stop producing leaves and grow flowers. Flowering occurs after about
3 months and seed can be recollected about a month later. Amaranths are called daylength neutral
plants because they still produce flowers at about the same stage, irrespective of whether there are
many or few hours of daylight. Because flowering stops harvesting of leaves, it is a problem, but
there does not seem to be any easy way of slowing down flowering. Flowering can be delayed a
little by picking out the tops down to a lower level. Also it is made a little later if plants are grown
in the shade. But lower picking and growing in the shade mean the plants produce less food, so
there is no point.
115
Plants need to be harvested and used when they are ready. If plants are left growing the
amount of harvestable leaf gets less and the quality gets poorer.
Pests and Diseases
Amaranths have some pest and disease problems.
Amaranthus insect pests
Beet webworm
Cacao armyworm
Shot hole weevils
Paddy bugs
Sucking seed
Nigra scale
Pineapple mealybug
Mealybug
Hymenia recurvalis
Tiracola plagiata
Oribius spp.
Leptocorisa spp.
Cletus sp.
Nisotra basselae
Parasaissetia nigra
Dysmiccocus brevipes
Planococcus pacificus
Pyralidae (LEP)
Noctuidae (LEP)
Curculionidae (COL)
Alydidae (HEM)
Colobathristidae (COL)
Chrysomelidae (COL)
Coccidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Beet webworm
An insect called the beet webworm damages the
leaves. The adult of this insect is a moth about 2 cm across
the wings. The wings are brown with white stripes. The
female moth lays eggs under the leaves and these hatch
out after about 5 days to grow into smooth green
caterpillars about 2 cm long. These caterpillars eat the
leaves and roll them up in a web. If needed, they could be
killed by a chemical called carbaryl, but it is poisonous so
needs to be handled carefully and people must not eat any
of the plants for 7 days.
Cluster caterpillar
Another insect called the cluster caterpillar can
also develop large numbers of caterpillars in some seasons
and badly damage amaranth. This insect can breed up on
other plants such as taro. The caterpillars stay together in
groups that gives them the name "cluster" caterpillar.
Caterpillar
Other insects have not been studied. At Wapasali, people complained of mole crickets
cutting off young plants and the young plants are probably chewed off, by the black cutworm.
Amaranth diseases
Fungus
Alternaria sp.
Fungus
Colletotrichum sp.
Fungus
Fusarium sp.
Nematode
Meloidogyne incognita
and
Meloidogyne hapla
Leaf spot
Leaf blight
Wilt
Root knot
Some diseases also damage amaranths. Young seedlings can be killed off by damping off
fungi such as Pythium and Rhizoctonia. These fungi attack the stem just near the ground level and
cause the young plants to fall over and die.
Also a fungus called Choanephora cucurbitarum (Burk et Rav) Thaxt. grows on the flowers
of pawpaws, pumpkins, taro and rice in Papua New Guinea and is known to be a problem with
amaranths in other countries. On amaranths it produces a wet rot of the leaves. This fungus is
blown by the wind from rotting plant material, where it is common, and then grows on the leaves of
amaranth. The wet rotting leaves become covered with grey fungal threads which have black heads
covered with a mass of small spores.
For both these diseases, the most practical village level control is to make sure plants are
growing as well as possible because healthy plants get less damage. This means good soil, good
sunlight and careful gardening. A few extra plants can be planted to make up for the ones which
die.
Amaranth as food
Amaranth leaves are very good quality food.
They are also popular. In the year 1670 a man called Rumphius said that in Asia amaranth
was "a captain among potherbs". Amaranths are now starting to receive a lot of attention by world
scientists. They have started holding worldwide conferences just to talk about amaranths. Many
people are starting to discover a plant that Papua New Guineans have had and enjoyed for a long
time.
Amaranths should be cooked because they can contain high levels of oxalates and cyanides
which could be harmful if eaten raw.
The amount of different nutrients in 100 grams of the leaves are:
Scientific name
Amaranthus lividus
Amaranthus spinosus
Amaranthus tricolor
Amaranthus viridus
Moisture
%
84.6
91.7
91.7
87.3
Energy
KJ
84
84
96
Protein
%
3.4
3.6
2.5
4.5
ProVit A
µg
292
ProVit C
mg
63
46
43.3
169
Iron
mg
Zinc
mg
2.3
6.0
0.9
How much will a small plot produce?
Yields of up to one kilogram of edible leaves have been harvested by pulling out plants from
an area of one square metre.
If plants are picked 3 or 4 times over 6-8 weeks then two kilograms of edible leaves can be
harvested.
117
From a plant that grows so quickly and is such good quality food this is a very high
production.
What signs does a plant on poor soil have?
The two most important nutrients that amaranth needs for good growth are nitrogen and
potassium. Plants need 16 different kinds of nutrients to grow properly and if any one runs out then
the plant normally shows this shortage in some particular way. If these two run out for amaranth
then the signs that the plant show are:Nitrogen - the oldest leaves near the bottom of the plant start going yellow. This is because
the plant needs more nitrogen to grow more new leaves at the top and there is not enough nitrogen
in the soil for it to get it from there. So it re-uses the nitrogen it used in the oldest leaves. These
leaves therefore go yellow.
Potassium - When this is short the edges of the oldest leaves go yellow.
These shortages of nutrients could be corrected by adding some nitrogen or potash fertiliser
but it is most likely too late for this crop. So you could learn a lesson and build up the soil better
for next time. Green plant material well composted provides nitrogen. Legumes also build up
nitrogen in the soil. Ashes provide potash.
Leafspot Amaranth
Grain amaranth
Blackberried nightshade
Scientific name: Solanum nigrum
The plant
This is a small leafy plant in the tomato and potato family. It is grown throughout the
tropical world as a nutritious leafy vegetable.
Growing blackberried nightshade
This plant is sown by seed in some areas of the country, especially in the lowlands. But in
the highlands it often just comes up naturally especially after grassland is burned with fire. In the
high altitude areas at about 2400 m it is the first edible green to be ready when a new garden is
established.
So this plant is common as both a sown and self sown vegetable in coastal areas and is
common as a self sown vegetable in the high altitude areas but is much less commonly seen in the
mid altitude zones between 800 to 1000 m.
Blackberried nightshade grows very quickly and produces lots of seed which also grow very
easily. This means it can beat weeds and is one of the first edible greens in a new garden.
Seed germination
1 week
Plant establishment 8-10 weeks.
Harvested 5-8 times over a 6-8 week period.
Seeds are normally sown simply by broadcasting them over newly prepared garden land.
Names
This plant can occur in similar types but they contain different numbers of the genetic parts
that control plant growth. These different types have been given different scientific names. It
appears they can all interbreed. Plants like this are called a polyploid series and those with 2 sets of
chromosomes are called diploid, those with 4 sets are tetraploid and those with 6 sets are called
hexaploid. So the different name used are:
Diploid (n=12)
Solanum nodiflorum
Tetraploid (n=24)
Solanum luteum
Hexaploid (n=36)
Solanum nigrum.
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Scientists are still discussing these variations because of their concern that some of these
plants may be poisonous. Many people in Papua New Guinea and in other tropical countries have
eaten large amounts of these leaves all their lives and have not suffered any ill effects.
As a food
This plant occurs in many countries of the world and in many areas outside the tropics it is
often regarded as poisonous. It has been tested in some tropical countries and no poison has been
found.
In trials this plant has been found to produce large amounts of highly nutritious leaves under
moderate fertility conditions.
The food value in 100 g edible portion
Edible portion
Leaves
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
87.0
160
4.3
3660
20
1.0
Zinc
mg
Pests and diseases
In Papua New Guinea not a lot of insects have been recorded on this food plant but also they
have probably also not been studied. The ones that are known to damage it include:
Potato tuber moth
Phthorimaea operculella
Soft scales
Icerya seychellarum
Pulvinaria ubicola
Saissetia coffeae
The only disease recorded on it is:
Bacterial wilt
Pseudomonas solanacearum
Probably some of the other diseases that affect tomato, potato and capsicum also affect it.
Ferns
Some times ferns are eaten in large quantities. At highland pig kills, ferns are one of the
most common edible greens. Some ferns are only eaten with meat. Some other ferns are eaten
more regularly. Some ferns are very much liked.
Ferns used as edible greens in Papua New Guinea
Asplenium affine
Blechnum sp.
* Callipteris prolifera
Ceratopteris thalictroides
Cyathea angiensis
* Cyathea contaminans
Cyathea rubiginosa
Cyclosorus truncatus
Dennstaedtia
Diplazium asperum
Diplazium cordifolium
* Diplazium esculentum
Dryopteris arbuscula
Dryopteris sparsa
Gleichenia
Helminthostachys zeylanica
Lomagramma sinuata
Microlepia speluncae
Microsorium commutatum
Microsorium irioides
Microsorium linguaeforme
Nephrolepsis biserrata
Orthiopteris sp.
Pneumatopteris sogerensis
Pteris moluccana
Selaginella opaca
Sphaerostephanos sp.
* Stenochlaena palustris
kumugras
tree fern
tree fern
tree fern
giant tree fern
Climbing swamp fern
The ferns marked with an asterix * are probably the ones most commonly used. Other ferns
as well are used.
Most of these ferns are not planted but are left when clearing land and are maintained and
sometimes transplanted. Normally they are eaten with meat. In some areas they are eaten in large
quantities when people kill large numbers of pigs.
With ferns it is mostly just the very young tender leaves that are cooked and eaten. So they
are harvested just after the fronds have started to uncurl but before they have begun to harden.
121
Climbing swamp fern
Tok Pisin:
Scientific name: Stenochlaena palustris
Tok Ples names:
Foi - tunane sai
Kaluli - sa
Podopa - orare
The climbing swamp fern
It is a climbing fern with a thin smooth rhizome which climbs up sago palms and tree
trunks. The fronds have several leaflets and they are often red in colour. The fertile fronds are
thinner than the other fronds and they are produced at the top of the plant.
Where does it grow?
This fern grows in the lower areas of the Highland Provinces and in other coastal areas of
Papua New Guinea. It probably grows up to 900 metres altitude above sea level. It also grows in
other warm countries. It likes to grow in a warm, waterlogged, partly cleared forest site. Therefore
it is suitable and common in sago type places. It cannot stand frost.
If you want to it is easy to grow from spores.
How is it used?
The young shiny leaflets are picked and cooked and eaten.
Tree ferns
Scientific name: Cyathea spp
Three different tree ferns have been recorded as being used for edible green fronds in the
highland regions. These are
Cyathea angiensis
* Cyathea contaminans
Cyathea rubiginosa
tree fern
tree fern
tree fern
* This is probably the most commonly used one.
(With Cyathea angiensis the fronds occur in a ring of 4 or 5 fronds around the stem and the
old fronds fall off immediately;)
These tree ferns can have a trunk up to 2 or 3 metres tall. The fronds are over a metre long
and they have scales on all surfaces.
The different species grow at different altitudes.
Cyathea angiensis
600 to 2200 metres altitude
Cyathea contaminans
200 to 1600 metres altitude
Cyathea rubiginosa
110 to 2840 metres altitude
They can very commonly
be seen being eaten at highland pig
kills. Normally they are only eaten
with meat and as meat is not a
common item in the diet people do
not eat these fern fronds every day.
Only the very young fronds are
used.
The ferns grow in high rainfall forest areas but commonly to grow in cleared grassland areas
if the roots are into moist soil. They are common in the higher altitude zones. When people are
making gardens they carefully leave these ferns to grow. Occasionally people transplant one to a
more suitable site or nearer their home.
They can easily be grown from spores on the back of the fronds. They can also be
transplanted if some of the roots are left on the trunk and the fronds are trimmed. They require
abundant moisture and often grow near streams. They also do best in light shade.
These plants are frost tender.
123
Diplazium ferns
Diplazium asperum
Diplazium cordifolium
* Diplazium esculentum
The naming of some of these ferns by scientists has been confused. Sometimes these ferns
are called Athyrium asperum, Athyrium cordifolium, and Athyrium esculentum.
Diplazium asperum
Diplazium cordifolium
Diplazium esculentum
250 to 1500 metres altitude
Diplazium asperum is a fern that has fronds up to 3 metres high. The stem of the fern is mostly
underground and densely covered with roots. The leaf stalk is rough. They grow best in humid
moist and lightly shaded places near creeks and on the edge of forests. They normally grow wild.
The young, not quite unfolded fronds are eaten cooked.
Diplazium cordifolium is a fern with a tufted rhizome and covered with brown or black scales. The
fronds are up to 50 cm long and 12 cm wide. They stick straight up. The fronds are not divided.
To grow it must have a minimum temperature over 10°C. It likes a moist protected situation.
Diplazium esculentum is the one of these three ferns that is most commonly recorded eaten. It is a
large fern with an upright stem. The leaf stalks are black near the bottom. The end sections of the
leaf are divided into many leaflets that are about 8 cm long and 1 cm wide. It is most common in
coastal areas and especially in wet areas. It occurs in Malaysia, Indonesia, Philippines and Fiji and
is used as a food in these countries.
Diplazium esculentum
Diplazium asperum
Kumugras
Tok pisin: Kumugras
Scientific name: Callipteris prolifera
Tok ples Kuanua: Tubua
This is a fern with a tough woody black rhizome and covered with black scales. They have a
narrow, black toothed edge. The fronds are erect and up to 2 metres long. They can be 55 cm wide.
They are fleshy and pale green. It likes hot humid conditions.
Water fern
Scientific name Ceratopteris thalictroides
This is a fern that grows in water and can float on
water. It can also grow on dry land in humid regions. It
grows as tufted clumps. The rhizome is short, upright and
fleshy with a few scattered scales. The fronds are up to 20
cm long. They are fragile and spongy and light green. The
leaves are like carrot tops. The fertile fronds are taller and
narrow with the edges curved back under.
It is common near the coast and up to 1200 metres
altitude. It is common in flooded coastal streams and near
mangroves in fresh water swamps. In other countries it
has often been grown along with rice, in paddies and also
in areas with flooded taro.
Small pieces of the plant will root in mud. The
spores can also grow into new plants.
The plant is edible. It can be eaten raw or cooked.
It is used for food in many tropical countries.
125
Fig leaves
Ficus ampelas
Ficus botryocarpa var. subalbidoramea
Ficus carica
Ficus copiosa
Ficus dammaropsis
Highlands kapiak
Ficus iodotricha
Ficus itoana
Ficus nodosa
Ficus pachyrachus
Ficus pungens
Ficus tinctoria
Dye fig
Ficus wassa
Papua New Guinea has a very large number of trees in the fig family. There are probably
more than 600 different ones. Many of them have not yet been properly described and named
scientifically. Figs have milky sap when the branches are broken. This family also includes trees
like breadfruit and mulberry.
For many of these figs the fruit or leaves are eaten.
Ficus copiosa and Ficus wassa are probably the two most widely used in the country. Ficus
dammaropsis or highlands "kapiak" is common in the highlands and the young leaves are eaten, the
fruit are eaten and the leaves are often used for wrapping food while it is being cooked. Ficus
tinctoria or the dye fig is common on some of the islands.
Ficus pungens
Ficus dammaropsis
Highlands kapiak
Ficus nota
127
Ficus pungens
(Scientific name)
No common Tok Pisin or English name
This is a fig family tree and therefore has white milky sap inside. The other part of the
scientific name "pungens" refers to the very sharp thorns that are on the small branches near the
leaves.
Young leaves
and thorns
It is a medium sized tree with large leaves about 25 cm across. The young leaves are light
green.
It grows small fruit on long stalks that hang down from the trunk of the tree. These small
fruit are about 0.5 cm across and are not eaten.
Small fruit hanging
on stalks from the
trunk.
Where does the tree grow?
It only grows in the lower areas below about 1600 metres above sea level. It is common and
used in areas like Tari, Poroma, Kagua and most of the lower areas. It mostly grows along the edge
of rivers and beside drains and creeks. It mostly just grows naturally from seeds.
How is it used?
The young leaves are cooked and eaten. They are normally only eaten with pig at pig kills.
Ficus copiosa
(Scientific name)
In some areas of the country this tree is planted, pruned and carefully looked after. At Tari
in the Southern Highlands, for example people grow this tree from cuttings and use it as a dividing
hedge between garden plots. It is pruned to keep its shape and the leaves are regularly harvested
and eaten.
But as well this fig tree grows widely naturally in many areas of the country and is
commonly used for food.
A leaf tip
A fruiting stalk
129
Kangkong
Scientific name: Ipomoea aquatica
What is the kangkong plant like?
Kangkong is a creeping sweet potato like plant. It has hollow stems and can float on water.
The leaves are green and are normally not divided like some sweet potato leaves, but the
shape and size varies a little between different kinds.
The trumpet shaped flower looks like a sweet potato flower and is normally white.
The runners develop roots at the nodes and also branch. This branching increases when tips
are picked off.
Names
Sometimes this plant is called water spinach in English. But more commonly the name
kangkong is used. Kangkong is the name used in Tok Pisin and is also the same in Malaysian and
Indonesian.
It was given the scientific name Ipomoea aquatica by a man called Forskal in the year 1775.
Sometimes other scientific names like Ipomoea reptans and Ipomoea repens are also used for the
same plant. The first name is the correct one. Two different varieties of kangkong occur. One
floats on water and is grown from cuttings and the other grows on dry land and is grown from
seeds.
Where is kangkong grown?
In Papua New Guinea kangkong is a coastal plant and probably only grows satisfactorily up
to about 1000 metres. It suits damp places and grows well in swamps. It can grow as a partly
floating plant in swamps and lagoons behind the beach along the coast.
Kangkong is grown in a number of other tropical countries including Malaysia, Indonesia,
Egypt, Fiji and especially Hong Kong and Taiwan. In some of these countries they grow the dry
land form in gardens.
Some of the leaf shapes in kangkong
Dryland kangkong
In recent years dryland kangkong has been introduced into Papua New Guinea. It is grown
in garden beds as a clumpy plant and the leaves are eaten.
131
Kalava
Scientific name: Ormocarpum orientale
The plant
This is a traditional green leafy vegetable in Papua New Guinea. Some of the Tok Ples
names for it are:
Rabaul
Kalava
Gulf Province
Ula
Kawito
Gaga lave
The scientific name was given it by a scientist named Merrill, who was studying the
collections of a Botanist called Rumphius, who had worked in the Mollucas West of Papua New
Guinea in the 18 century.
This plant has name been taken to some other places in Papua New Guinea as a food by
people have they have moved to live or work. It can be seen in places like Manus and Kimbe.
As well as being planted it also grows wild in the scrub just behind the beach. The wild
type is also eaten. Amongst the Tolai people at Rabaul this is one of the shrubs planted as a
boundary marker. It mostly occurs below 30 m altitude.
It is a leguminous shrub. It grows to about 7.5 m tall and
has a light brown bark which strips off showing greener bark
underneath. The leafy shoots are hairy. When the plant flowers
it has a flower like a bean and a pale yellowish green in colour
with reddish veins. It produces a pod that is up to 9 cm long and
jointed in a chain of 2 to 8 seeds. The seeds are small 5 mm and
bean shaped. The kind that is planted in gardens tends to have
thinner twigs that hang over and the leaves are finer.
It can be planted by cuttings. It also grows from seed.
Rungia
Scientific name: Rungia klossii
The Rungia plant
It is a clumpy much branched bush about 40 cm high. Often the leaves are dark green but
varieties occur with yellow patterns on the leaves. It has a pale blue flower. At least 20 different
varieties occur.
A market bundle of Rungia
and Setaria pitpit
Names
This plant has the scientific name Rungia klossii. It was given this name in 1916 after the
plant was first collected on a botany expedition into West Papua in 1912. This expedition was
organised by a Mr. Baden Kloss from the Museum at Kuala Lumpur in Malaysia, so the second part
of the name was called after him.
In English it has no common name but could easily just be called Rungia. It has Tok Ples
names in highland areas of Papua New Guinea. eg.
Place
Mendi
Tari
Eastern Highlands
Tok ples name
taine
kereba
moku
133
Where does Rungia grow?
Rungia is only known from Papua New Guinea and Irian Jaya. It occurs in the highlands and
grows up to about 1900 metres altitude. In recent times it has been taken down to the coast but as it
doesn't grow fast enough to be able to compete with weeds in coastal areas, it is less important.
In some areas such as Telefomin the plant is only poorly known as a wild plant and people
pick leaves from selfsown plants in the bush. But in most other highland areas it is one of the most
popular and most widely cultivated green leafy vegetables.
The most important areas for Rungia are between 1000 and 2000 metres altitude.
How do you grow Rungia?
Rungia is grown from cuttings. Often cuttings about 25 cm long are used. These stems
often already have roots developing from the nodes or quickly develop roots. A number of these
cuttings are often planted together giving a clump of plants. These grow slowly at first. It requires
a fairly fertile soil and a damp area. Plants are put about 50 cm apart.
Rungia is planted at any time of the year. It takes about 3 to 4 months for a plant to be
maturely established. Once established the young tips (2 or 3 leaves) are picked regularly. Regular
picking keeps branches short and productive of leaves. The leaves are picked at 1 or 2 monthly
intervals for a couple of years.
Rungia is commonly grown in new sweet potato gardens with either sweet potato or
highland pitpit in highland gardens.
How much is produced?
The tips that are picked weigh about 0.8 g. One plant produces about 2 kg of leaf tips over a
one-year period. If the plants were spaced at 50 cm spacing this would give a yield of 4 kg per
square metre of garden.
Rungia as food
The young leaf tips are eaten raw or cooked. After harvesting they will not keep very long.
(2-3 days).
Food value (per 100 g of edible portion)
Moisture Energy Protein Calcium proVitA
%
cals
g
mg
!g
Leaves
87.9
33
2.5
272
provitC
mg
Iron
mg
Zinc
mg
Dicliptera papuana
(Scientific name)
No common English or Tok Pisin name
The plant
This is a clumpy, much branched bush. Most people in villages recognise it as related to
Rungia. It grows naturally along damp creek banks. It forms a leafy bush up to 1 metre high.
It produces flowers in clumps in the place where the leaves join the stem. The flower petals
are blue.
There are small hairs on the leaves and stems. The stems have small grooves running along
them.
A leaf tip of Dicliptera
drawn almost true to size
A flowering stalk and
flower with blue petals
How is the plant grown and used?
This plant is planted in gardens in some areas such as the Mendi valley above Mendi and in
the Baiyer area. In other areas such as near Lake Kutubu in the Foi area it is harvested from the
wild but not planted. At Pangia the Wiru people never eat it.
It grows easily from cuttings of the stem. Normally a group of stalks are planted together to
produce a clumpy bush.
The leaf tips are picked and cooked.
135
Valanguar
Names
Tok Ples Kuanua: Valanguar
Scientific name: Polyscias spp.
Because this plant varies a lot and produces many different leaf shapes the scientific naming
has become very confused. Many different names have been used. The names Nothopanax, Aralia
and Panax have been used as well as a number of other names. It seems the correct name is
Polyscias but all the different species or varieties have not yet been sorted out. Most likely the
ones used for food are:
Polyscias cumingiana
Polyscias fruticosa
Polyscias macgillivrayi
Polyscias scutellaria
Polyscias verticillata
Polyscias fruticosa
Polyscias verticillata
Polyscias guilfoylei
Polyscias multijuga
Polyscias scutellaria
Polyscias samoensis
Some of these are used in the Solomon Islands and in other Pacific islands.
Because of the amount of confusion over the naming of this plant and the amount of
material written about it, a summary of the different names often used is given in this table.
Polyscias cumingiana (Presl.) F Vill.
Syn.
Panax pinnatum Lamk.
Panax secundum Schilt.
Paratropia cumingiana Presl.
Aralia filicifolia C.Moore
Panax rumphiana Harms. etc.
Polyscias fruticosa (L.) Harms.
Syn.
Panax fruticosum L.
Aralia tripinnata Blanco
Nothopanax fruticosum (L.) Miq. etc.
Polyscias macgillivrayi (Seem)Harms
Syn.
Nothopanax macgillivrayi Seem
Panax macgillivrayi (Seem) Benth.
Polyscias grandifolia Volkens etc.
Polyscias scutellaria (Burm.f.) Fosb.
Syn.
Scutellaria prima Rumph.
Crassula scutellaria Burm.f
Aralia cochleata Lamk.
Panax scutellarioides Reinw. ex Bl.
Nothopanax cochleatum (Lamk.) Miq
Nothopanax scutellarium (Burm.f.) Merr. etc.
Panax verticillata Stone
This plant is probably most commonly known as a food amongst the Tolai people of Rabaul
and they have taken it to other places in the country. It is often used to form a hedge around their
houses and gardens. Constantly picking the leaves helps maintain it as a small pruned shrub. As a
shrub they grow from 2 to 5 m tall. The species is probably Polyscias verticillata.
The leaves are yellow or pale green. They are used for food from Indonesia to the Pacific
Islands but are also grown in many areas simply as an ornamental.
The plants are easily grown from stem cuttings.
The young leaves have a nice smell and are used as a vegetable as well as to flavour stews.
137
Tu lip
Tok Pisin: Tu lip
Scientific name: Gnetum gnemon
What does a tu lip tree look like?
It is a small tree often only 8-10 metres high. It is a fairly straight tree with one trunk that
has branches spread out along its length. The branches are not very long so that the tree does not
spread out very wide.
Drawing by Celia Bridle
The tu lip tree
In Tok Pisin this small tree is called tu lip. As people in Holland and other countries grow a
flower called tulip, we need to point out that the two plants, or their names have nothing in
common. The "tu-lip" tree has no common English name although in some countries it is called
jointfir. Scientists use the Latin name of Gnetum gnemon. This name was given to it by a famous
botanist called Linnaeus more than 200 years ago.
People in Papua New Guinea call it "tu lip" because of the way the leaves are arranged. It
has two leaves (tu lip) opposite each other along the branches. Often the branches also come out in
pairs opposite each other.
The fresh young leaves have a slightly brownish green colour and are in pairs. The older
leaves are dark green and shiny.
When the tree has fruit it can be covered with green nut-like fruit that turn red when ripe.
139
The male and female flowers are separate and are on different trees. So only female trees
bear fruit. The flowers are grouped on spikes that develop near the base of the leaves. The flowers
are yellow.
This tree in common with some other closely related plants that are called Gnetum has rings
or hoops at the places where the leaves occur. These can be seen in this picture.
Gnetum latifolium
Gnetum gnemon
A tu lip tree has ridges running across the trunk that can help you recognise the tree
Why is the tu lip tree so useful?
The young leaves of the tree are eaten and are a very popular green vegetable. They are
very good quality food. They have been described as one of God's good gifts to Papua New
Guinea.
The nut like fruit and seeds can be eaten. They are also very good food value.
The bark of the tree is good for making ropes and nets.
The timber can be burnt green, as firewood.
The timber will last for a long time when used for posts in wharves in fresh water.
Where does the tu lip tree occur?
It grows wild in lowland and lower mountain regions of Papua New Guinea. People in these
areas look after it and leave it growing when they are clearing new gardens in the rainforest. They
often transplant seedling trees into their gardens and they also grow their own trees from seed.
But the tu lip tree is common in a number of other Asian and Pacific Island countries.
Another famous botanist called Rumphius spent many years in Asia. In the year 1670 he
commented on the tu lip tree in his notebook. The picture and his comments are reproduced here.
What is the food value of tu lip?
In 100 grams of the part you eat the following amounts of different kinds of food occur.
Moisture Energy Protein Calcium
Iron
proVitA provitC Zinc
%
cals
g
mg
mg
!g
mg
mg
Leaves
75.4
43-90 3.9-6.4 266-330 2.7-7.7 5900-7100 113-200
Fruit
80
66
5
163
2.8
600
100
Dry seeds
345
12
0
This means that the leaves are very good quality food. The fruit and seeds are also very
good quality food. If you eat a nice big bowl of these leaves they will provide a lot of your bodybuilding and your health food needs.
How do you prepare the food?
The young tender leaves are picked and boiled or
fried.
The red fruits that are about 2.5 cm long can be
eaten raw but they are tough.
The seeds of the ripe fruits are eaten roasted,
boiled or fried. Before cooking the seeds it is necessary to
either remove the tip or crush the seed, or seeds can
explode on heating.
The young flowers including the young fruits are
sometimes cooked and eaten.
141
Snack foods
from tu-lip
Because the parts eaten can contain irritating substances the various parts are normally
cooked before being eaten.
How do you grow tu lip trees?
Tu lip trees often grow wild. You can find a small wild plant in the bush and transplant it to
where you want it.
You can also grow trees from seed. Collect a very ripe red fruit from a tree. It has one seed
inside. If you simply plant it the seed sometimes takes a long time to start growing. You may have
to wait 6 months. This is because the seeds have a hard outside layer and it is difficult for moisture
to get in to start the seed growing. To get the seed to start growing more quickly you can carefully
file a small hole through the outside layer of the seed.
If you are going to plant several trees they should be planted about 6 m apart.
Because this tree grows naturally under larger trees in the rainforest it is suited to growing
in places where there is some shade. Therefore you can plant the tree in a partly shaded place if you
want to.
If you want to, you can grow trees from cuttings. This means you take a small branch off a
tree and plant it in warm moist soil where it will develop roots and grow.
How much food?
The leaves of very small seedling tu-lip trees in the rainforest are harvested of their young
leaves as people walk past. So an early harvest can be gained. Like many tropical trees, tu-lip trees
grow by producing flushes of new leaves throughout the year. So leaves are not always equally
available. In fact many tulip trees have fresh young leaves for picking at one main season of the
year.
It is not equally important in all these areas. At Erave people harvest it out of the bush
where trees grow naturally. But they don't use it a lot. At Podopa villages, like Woposali and Boro,
and Foi villages such as Hegiso, trees are grown in and around the villages. People in these areas
recognise and have names for 3 or 4 different varieties. Near Bosavi, the Kaluli people mainly
harvest leaves and seeds from wild trees. Although trees are rarely planted the self-sown trees are
protected when clearing bush for gardens and they are look after in gardens.
Pests and diseases
Tu-lip insect pests
Eucalymnatus tessellatus (Signoret)
Coccidae (HEM) soft scale
Milviscutulus mangiferae (Green)
Coccidae (HEM) soft scale
Probably the insect pests of tu-lip have not been properly studied.
Watercress
Names:
English: Watercress
Tok Pisin: Wara kebis
Scientific name: Nasturtium officinale
The plant:
This plant has been introduced but has become an important and popular edible green in the
highlands regions.
This small plant keeps living for many years once established. The stems are hollow,
angular and with many branches. The plant has roots along the stem at the node and cuttings
quickly form roots in water. The leaves consist of 3 to 7 pairs of small leaflets then a larger leaflet
at the end. The flowers are small and white and a small narrow curved seedpod is produced.
Flowers are not always produced and need days with more than 12 hours of sunlight to form.
It is grown from rooted sections of the plant. These are established in the mud beside a
stream or in a shallow flowing creek. Once it is established it often keeps growing with very little
care or maintenance. It does best in creeks that flow off limestone country. Plants can float on the
water. It will not tolerate drying out. It can also be grown from seeds.
The young leaves and stems are eaten. They can be eaten raw and has a spicy flavour. It
can also be served cooked. Cooking should be used if the water in the stream is not pure and clean.
This plant keeps growing well in mountain streams up to at least 2900 metres altitude.
143
Rorippa
Names:
There are several plants in Papua New Guinea that are probably all Rorippa spp. but several
of them have been called Nasturtium sp. They are grown or used as food plants. These include:
Rorippa schlechteri
Rorippa islandica (Oed) or yellow marsh grass. This one is self sown and used in the high
altitude regions.
Rorippa schlechteri is grown as a vegetable in gardens in the highlands. It is sown by
broadcasting the seeds. Because it has a well-developed taproot, the plant does not transplant
easily. Normally the whole plant is eaten cooked.
Plants grow quickly and are harvested after 4 to 6
weeks.
It is common in the highlands from 1000 to 2200
metres altitude but will grow down to the coast.
It appears to get damaged by similar insects to cabbage.
Insect pests
It is badly damaged by caterpillars of the insects that commonly damage cabbage in the
highlands especially the cabbage cluster caterpillar.
Cabbage cluster caterpillar Crocidolomia binotalis Pyralidae (LEP)
The caterpillars of this moth have an orange head and are green with
3 white lines on top. They are up to 2 cm long and live for 14 days. The
moth is 12 mm long and with a wingspan of 22 mm. The moth is greyish
brown with irregular markings. There are two small white spots of the front
wings. These caterpillars eat holes in the leaves of a number of plants in the
cabbage family. They leave dark chewed-up lumps on the leaves. They can
regularly cause 90% damage to the more leafy types. Plants damaged include
Nasturtium schlechteri. The insect avoids light so eats on the underside of
leaves. They are difficult to control but can be controlled with chemicals.
Diamond back moth Plutella xylostella (L.) Plutellidae (LEP)
This moth is brown with a diamond shape on its back. It is about 7
to 12 mm long. The green caterpillars eat irregular shaped holes on the
leaves of cabbage family plants. They are very common. The larvae drop
from the plant on silken threads when they are disturbed. They damage
Nasturtium schlechteri, and other plants in the cabbage family. The moth
tolerates a wide range of climates but gets worse in hot dry areas. They are
difficult to control but can be controlled with chemicals.
Black cutworm Agrotis ipsilon (Hufnagel) Noctuidae (LEP)
The caterpillars of this moth are brown on top with green sides and
up to 30 mm long. They have a shiny skin. They cut off seedlings at ground
level. They hide in the soil coiled up in a ball. The moth has a wingspan of
40 to 50 mm and the front wings are brown while the rear wings are
yellow/brown. They do this damage at night. Damage occurs in a range of
plants grown from seed including Rorippa sp., and cabbage. They tend to get
worse in areas that have been low-lying damp areas especially where there
have been many weeds present.
145
Water dropwort
Scientific name: Oenanthe javanica
The plant
This plant is a hollow stemmed creeping green leafy vegetable. The stem is often up to 100
cm long and normally lies along the ground and turns up near the tip.
The leaves are finely divided like carrot tops but the size, shape and colour of the leaves can
vary quite a bit, even on the one plant. The leaves often have leaf sheaths that wrap around the
stem.
The flowers occur at the ends of the branches and are a group of small white flowers.
Where does the plant grow?
In Papua New Guinea this is one of the commonest green leafy vegetables of the Highland
areas. In recent times it has been introduced into coastal areas and still grows quite well. Floating
masses of it can be seen in some coastal streams such as West New Britain.
In the highland areas it is common in gardens up to 2600 metres altitude and has been seen
growing up to 3400 m altitude.
It normally grows near creeks or in wet or damp patches in gardens. The hollow stemmed
branches can actually float on water and the plants seem to thrive along drains and ditches.
This plant is also grown as food in several other countries. It is common in Indonesia and
Malaysia and is also grown in India, Vietnam, China, Taiwan and a number of other South East
Asian and Pacific countries. It is a traditional vegetable with ceremonial importance in Japan.
Names
Because the leaf shape and appearance of this plant can vary considerably, it has had some
different scientific names. The correct name is Oenanthe javanica and it was given this name by a
scientist called De Candolle in 1830. The other most commonly used scientific name has been
Oenanthe stolonifera but as the two plants are the same this name has now been replaced.
It has no commonly accepted English or Tok Pisin name. Names such as water celery and
water dropwort have been used in English. Because several other Oenanthe spp. plants are very
poisonous, it is probably not a good idea to just use "oenanthe" as the name and run the risk of
confusing a good vegetable with other poisonous plants. It has many different Tok Ples names.
Growing water dropwort
This plant often grows wild. These selfsown plants are not as tasty as the cultivated types
but they are eaten.
The plant is also grown in gardens. It is planted by using cuttings. Often 5 or 6 cuttings are
planted in a hole made with a digging stick. In moist soil the plants establish quickly and easily.
It is also possible to grow the plants by seeds, but these are rarely used in PNG.
Water dropwort as food
The leaves and young tips of the plant are often eaten raw or cooked.
The amount of different nutrients in a 100 g sample of this food is shown in this table.
Leaves
Moisture
%
90.6
Energy
cals
28
Protein
g
1.8
Calcium proVitA provitC
mg
!g
mg
113
2190
14
Iron
mg
3
Zinc
mg
A chemical called myristicin has been shown to occur in water dropwort. Because of this, it
may not be good to eat large amounts of this vegetable.
Leaf shapes
Market bundle
147
Waterleaf
Tok Pisin:
Scientific name: Talinum triangulare
The waterleaf plant
This plant is a small shiny leafed plant that grows up to about 60 cm tall. The leaves have
very short stalks and are fairly soft and light green in colour.
The plant produces a flower stalk at the top. This stalk is triangular shape. A clump of
pale pink flowers, with 5 petals, grows at the top.
The plant grows upright and has a number of branches.
Where is waterleaf grown?
Waterleaf or Talinum is grown in a number of tropical countries. Tolai people say the
Japanese brought it to the Gazelle. How long it has been in Papua New Guinea is not known, but it
has only recently been brought from the Gazelle Peninsula to the Kutubu area in the Southern
Highlands. It is seen in some coastal areas but not always used.
It is grown in Africa, South America, Indonesia and the Philippines. It suits the lowlands
probably below about 1000 metres altitude as it does best in hot places.
How do you grow waterleaf?
Waterleaf can be grown from seeds or cuttings.
The seeds are very small and black. It takes 4000 seeds to weigh one gram. It is not easy
to collect seeds because the seed capsules split open very easily and the seeds drop out. Also plants
don't always produce seeds readily. But you can collect seeds and grow plants from seeds. This is
easiest by sowing seeds in a small nursery then transplanting the small plants when they are about
5-8 cm high. With very small seeds like these, it is best to mix the seeds with dry sand before
sowing. Then a small amount of the seed/sand mixture can be sown and the seeds will not be too
close together. Seeds will grow in about 6 days.
Another way to grow waterleaf is to use cuttings. Cuttings of 15-20 cm long can be taken
from the older, but not the woody part of the stem. The leaves should be taken off the cuttings.
The cuttings need to be planted in warm moist soil. They should be about 20 cm apart.
Older waterleaf plants can be cut back and allowed to sprout again.
Is waterleaf in any way special?
Waterleaf is one of the plants scientists call C4 plants because it has some special ways of
moving food around and storing food inside the plant. This means it can normally grow very fast if
it is given the right conditions. The conditions these types of plants prefer are high temperatures,
high soil fertility, plenty of sunlight and sufficient water. But even though the plant grows best
under these conditions it doesn't have to have them. It can grow reasonably well under lower soil
fertility conditions and is very good at surviving dry times and will grow with a little shade.
How is waterleaf used?
The young tender leaves and tips of branches are picked off. Sometimes they are eaten
raw in salads, but more commonly they are cooked. The bottom part of the leaves sometimes turns
slightly brown on cooking and the cooking water can become a little coloured. It is best to steam
the leaves in bamboo.
The leaves have a slightly sour taste and are a little slimy.
Pests and diseases
In other countries few pests or disease problems have been noticed. These have not been
looked at in Papua New Guinea.
How much food is produced?
In other countries, waterleaf plants are ready to start picking after about 4 weeks. Leaf
tips may be picked every two weeks for up to a year. Normally the top shoots are picked out first,
to let the side shoots grow.
Up to 5 kg of edible tips have been harvested from one square metre area of plants over
one year.
Food value
Waterleaf leaves are a quite reasonable quality green leaf vegetable.
The amount of different nutrients that it contain in each 100 gram portion of the leaves
that are eaten is shown in this table.
Leaves
Moisture
%
92.4
Energy
cals
23
Protein
g
1.9
Calcium
mg
90
Iron
mg
4.8
proVitA
!g
3
provitC
mg
60
Zinc
mg
These leaves contain reasonably high levels of the chemical called oxalates. This is the
chemical that causes some taro plants to burn your throat and it occurs fairly commonly in tropical
leafy vegetables. Too much of it is not good.
149
Vegetables
Bamboo
- small and large
Beans
- common bean
- cowpea
- long or snake bean
- lablab bean
- lima bean
- cabbage
- Chinese cabbage
- Nasturtium schlechteri
Cabbage family
Capsicum and chilli
Corn
Ginger
Job's tears
Peanut
Pitpits
Pumpkin family
Onions
- coastal or long pitpit
- highlands or short pitpit
- bottle gourd
- choko
- cucumbers
- pumpkins
- angled loofah
- smooth loofah
- bitter cucumber
- Trichosanthes pulleana
- leeks
- spring onions
Bamboos
Bamboo
One of the common bamboos in Papua New Guinea is the coastal bamboo or mambu in Tok
Pisin which is grown near houses and is used for cooking utensils and building materials and also
has shoots which are eaten. It is easily grown by planting cut portions of the green stalks.
In the highlands from about 1200 m altitude to 1900 m another large bamboo is grown.
This one is traditional to Papua New Guinea and is common in large clumps near houses. It is
commonly used for cooking leaves and small insects and sago and pieces of meat over the fire. It is
also used for carrying water. It has young shoots that are cooked and eaten.
In some areas especially near Lake Kutubu, there is another small bamboo that is grown in
gardens and eaten like a pitpit. They are planted from cuttings of the cane and take about one year
to produce. The young shoots are cooked and eaten. This bamboo has canes that grow about 5 m
tall but often they do not stay erect but fall over on the ground. The canes are about 3 cm thick. It
flowers almost continually and this plant is also harvested from the wild and eaten.
Bambusa vulgaris
Nastus elatus
Bambusa forbesii
Nastus elatus
151
Bambusa forbesii
Beans
Several different beans are grown for food in Papua New Guinea. These include:
Common bean
Snake bean
Lablab bean
Lima bean
Winged bean
Cowpea
And some less well known ones like:
Mung bean
Green gram
Scarlet runner bean
Soybean
Rice bean
Yam bean
Sword bean
Jack bean
Velvet bean
Adzuki bean
This article will mainly be about common bean, snake bean, cowpea, lima bean and lablab
bean. These are the ones most widely grown throughout the country. Winged beans are important
but are dealt with separately. Peanuts are also described in a separate article.
Common bean
Yardlong bean
Rice bean
Cowpea
Lablab bean
Lima bean
Sword bean
Scarlet runner bean
Jack
bean
Broad bean
Soybean
Yam bean
Pigeon pea
153
Winged bean
Common bean
Scientific name: Phaseolus vulgaris
Common bean or French bean can be either a short or a climbing bean. It occurs in many
different varieties. The pods are slightly curved and with a distinct beak at the end. Normally there
are 4 to 6 beans in a pod. The climbing kinds can be 2 metres tall and the dwarf ones 20 to 60 cm
tall. There are also kinds that are grown for the dry mature seeds but these are less common in food
gardens.
The unripe pods are cooked and eaten.
These beans perform reasonably well in the highlands but mostly in the lowlands they are
too badly damaged by pest and disease.
Snake bean
Scientific name: Vigna unguiculata subsp. sesquipedalis
Names
This bean has been called yard-long bean and sometimes the vegetable cowpea and in other
places, the asparagus bean.
What is the bean like?
Mostly this bean is a climbing bean grown in the lowlands. There are short or dwarf
varieties available but these are normally not popular. The pods can be up to 1 metre long and are
flexible and mostly less than a centimetre thick. The seeds are widely spaced in the pod. This bean
is grown from sea level up to about 300 metres altitude. It is normally easier and more successful
to grow this bean than common bean in the lowlands.
How does it grow?
This bean grows very quickly and well on the coast of Papua New Guinea. It needs to have
sticks to climb up or can be put near a fence of small tree. Often, a circle of sticks tied together, are
placed in a circle and a number of seeds planted in a mound. It only grows as an annual bean so
seeds need to be replanted each year. It needs a good rainfall and is not suited to areas with
drought. When the climbing bean is growing very vigorously the top is picked out to prevent it
getting too tall.
How is snake bean used?
Mostly the young green pods are eaten cooked. The young shoots are also eaten cooked.
The ripe seeds can also be eaten. The pods need to be harvested every 2 or 3 days.
Diseases and pests
Although this bean gets most of the insect and disease problems of other beans it is normally
less damaged and can give very good production in most places. Maybe a part of the reason is that
it grows very quickly. It can be badly attacked by aphids. Diseases get worse if the bean does not
have sticks to climb. The damage by bean pod borer is less if snake beans are grown intercropped
with maize. It does not seem to affect the yield of corncobs where beans are grown with them.
Cowpea
Scientific name: Vigna unguiculata
This bean is grown as a cover crop in some plantations and is also a good vegetable. In
some areas of Papua New Guinea it has become popular and common. The Baiyer River area is
one such area. It will grow from sea level up to about 1800 metres altitude.
What is the bean like?
It is a creeping bean type of plant with short
straight, firm pods. Some kinds produce more leaves and
are used more as cover crops and other kinds produce
more pods and seeds. These are the ones that are best as
vegetables. Flowers occur in pairs at the end of the
flowering shoots.
How is it used?
The young pods can be eaten and the
young leaves can also be cooked and eaten.
The more mature seed pods are often cooked
then the seeds eaten from the pod by running
the thumb along the length of the pod to push
the seeds into the mouth.
155
Lima bean
Scientific name: Phaseolus lunatus
What is this bean like?
This is vigorous climbing bean that can keep growing for some years. The leaves are
slightly rounded at the base and pointed at the tip. The flower is white or yellow. The keel of the
flower is twisted which helps tell the difference between this bean and Lablab bean. The pods are
flat and have 3 or 4 seeds that vary in colour. The seeds are large. The pods are long (10 cm),
flattened and curved. The curved pods were considered like the moon, so were given the Latin
name lunatus or moon. The seeds have a short round hilum where the seed is attached to the pod.
The seeds also have lines going out from this point across the bean seed. It is one of the traditional
beans in the highlands of Papua New Guinea.
Where does it grow?
It most commonly occurs between 500 metres and 2100 metres altitude in the highlands, but
it will grow up to the limit of cultivation at about 2700 metres. It needs a soil temperature of above
15.5°C for the seeds to germinate and a day temperature of about 22°-30°C for satisfactory
flowering. It does not suit waterlogged soil.
How is it grown?
It is grown from seed. Coloured seeds are often hard to get to grow but white seeded kinds
start growing easily. So for coloured kinds, it is important that they are planted when regular rain
occurs as the water washes away some of the chemicals that stop the bean growing.
When is food produced?
Young pods can be harvested about 3 months after planting beans.
What is the food like?
Leaves tend to be bitter and seeds can also contain poison. They should be cooked and the
cooking water changed. White seeded varieties have less of this problem than the highly coloured
seeded kinds.
Diseases and pests
A rust fungus grows on the leaves. The fungus is called Phakopsora vignae.
157
Lablab bean
Scientific name: Lablab purpureus
This plant has been given different scientific names at different times. The correct name is
Lablab purpureus and the other two names Lablab niger and Dolichos lablab are now no longer
correct. It is similar in many ways to lima bean (Phaseolus lunatus). It can be distinguished from
this other bean because the keel or boat like part of the flower is not twisted and there is a long
point on the end of the pod. As well on the seeds there is a long narrow white slit (hilum) where the
seed is attached to the pod.
Because this is a traditional bean in the highlands of Papua New Guinea it has names in Tok
Ples but often no Tok Pisin name that distinguishes it from other beans. A number of different
varieties occur in village gardens.
It is a plant that could keep growing from year to year, but mostly in Papua New Guinea it
only lasts for a short time of 1 to 3 years. It is a climbing bean and the vines can be from 1 to 5
metres long. For this reason it is often planted near fences or at the edge of gardens. The leaves are
made up of 3 almost triangular leaflets. The plant often has a purple appearance. The flowers are
mostly white but they can be red or blue. They are produced on a long flower stalk.
The pods are flattened with a pointed end and can be up to 12 cm long and 2 cm wide.
There are between 3 and 5 seeds inside and these can vary from white to a dark colour.
Where does it grow?
This bean is mostly grown between 750 and 2175 metres altitude. It is a bean that can
survive a drought and can grow in low rainfall areas. It can grow on poorer soils but does not do
well on waterlogged soil. It is good at fixing nitrogen in the soil. It needs temperatures between
18°C and 30°C to grow best. It can continue to grow where temperatures are down to 9°C. Light
frosts will damage the leaves but may not kill the plant. In humid weather less seed pods form.
How quickly is food produced?
Young pods are ready for harvesting between 4 to 6 months after the beans are planted and
the mature seeds are ready between 6 to 8 months after planting. The pods can continue to be
harvested over 2 or 3 years. In cold weather less flowers and pods are produced.
Which parts are eaten?
It is possible to eat the young leaves and shoots as well as the young pods and the ripe seeds.
They should all be cooked as some types can have a poison in them. With some types, the cooking
water is thrown away, as it contains the poison after cooking.
This bean can have a thickened root that can be eaten.
What pests and diseases cause problems?
Two fungal diseases are often seen on these beans.
These are angular leaf spot due to a fungus called Cercospora canescens and a leaf spot due
to a fungus called Ascochyta dolichi.
These diseases seem to commonly occur but they may not result in serious loss of beans.
159
Food value of bean family plants per 100 g edible portion
Common name
Aila
Common bean
Common bean
Common bean
Common bean
Common bean
Common bean
Cowpea
Cowpea
Cowpea
Cowpea
Cowpea
Green gram bean
Green gram bean
Green gram bean
Kudzu
Lablab bean
Lablab bean
Lablab bean
Lima bean
Lima bean
Lima bean
Mung bean
Mung bean
Peanut
Peanut
Pigeon pea
Pigeon pea
Rice bean
Scarlet runner bean
Soybean
Soybean
Soybean
Velvet bean
Winged bean
Winged bean
Winged bean
Winged bean
Winged bean
Moisture
%
43.0
10.0
92.0
88.0
77.3
80.4
Energy
KJ
1008
1386
142
151
351
304
Protein
%
4.5
25.0
3.0
2.5
6.6
5.6
ProVit A
µg
0
10
90.7
11.2
88.4
91.3
75.5
89.5
121
1189
143
92
406
142
439
1432
126
4.2
23.5
4.2
4.7
3.2
2.6
7.0
22.9
3.0
2.1
22.8
4.5
3.0
19.8
6.8
6.8
22.0
2.0
24.3
15.0
19.5
6.0
20.9
20.3
33.7
13.0
8.5
29.32
41.9
7.0
2.1
11.6
5.0
0
11.0
90.4
68.6
10.0
82.0
86.9
12.0
67.2
70.2
12.0
93.4
4.5
45.0
10.0
71.8
13.0
12.0
9.0
68.0
79.5
7.29
8.5
87.0
92.0
57.4
95.0
1428
209
1407
515
473
981
88
2364
1394
1449
464
1373
1419
1701
584
339
1764
205
105
619
197
Provit C
mg
2
1
20
27
25
17
Iron
mg
Zinc
mg
8.0
0.8
1.4
1.8
1.3
2.8
0.2
0.2
1.0
14
Tr
37
30
24
1
0
Tr
55
13
Tr
1
5.1
0
10.1
23.4
Tr
11.4
Tr
10
Tr
28.1
0.8
6.4
4.7
1.1
1.1
0.7
1.4
7.1
0.9
0.6
9.0
10.0
0.8
5.6
2.5
3.1
8.0
0.7
2.0
1.5
15.0
1.6
10.9
9.0
6.1
3.8
1.3
0.4
712IU
576IU
79
45
2.4RE
55
2
38.7
1.5
35
18
2.2
17.0
1.0
4
13.2
750
668
Tr
55
16
1
7
13.0
27
8.3
4.78
Tr
18.3
0
809
0
30
0.3
0.2
1.0
0.2
0.4
0.4
0.8
0.8
0.5
3.0
0.8
0.9
1.0
15.0
1.5
0.4
2.0
6.2
1.4
1.3
Edible portion
Nut
Seeds dry
Seeds green
Pods green
Pod + seed
Seeds green
boiled
Seeds sprouted
Seeds - dry
Leaves raw
Leaves - boiled
Seeds boiled
Pods boiled
Seed cooked
Seeds dry
Seed sprouted
Roots
Seeds - dry
Pods fresh
Seeds - young
Seed dry
Seed - cooked
Seeds raw
Seeds - raw
Seeds sprouted
Seed dried
Seed fresh
Seeds dry
Seeds young
Seeds
Seeds
Seeds
Seeds immature
Seeds sprouted
Seeds
Seed dry
Seeds - young
Pods fresh
Roots
Leaves
Diseases of the bean family of plants
Aila nut
Fungus
Helotium inocarpi
Fungus
Fungus
Fungus
Fungus
Fungi
and
Fungus
Fungi
and
and
and
Fungus
Fungus
Virus
Nematode
and
Bacteria
Fungus
Alternaria tenuis
Ascochyta phaseolarum
Colletotrichum lindemuthianum
Phaeoisariopsis griseola
Athelia rolfsii
Rhizoctonia solani
Thanatephorus cucumeris
Cercospora canescens
Cladosporium oxysporum
Corynespora casiicola
Periconia byssoides
Mycovellosiella phaseoli
Uromyces appendiculatus
Bean common mosaic virus ?
Meloidogyne arenaria
Meloidogyne incognita
Xanthomonas phaseoli
Aspergillus sp.
Fungus
Fungus
Fungus
Fungus
Fungus
Ascochyta sp.
Cladosporium sp.
Epicoccum sp.
Fusarium sp.
Phoma sp.
Fungus
Oidium sp.
Fungus
Fungus
Fungus
Fungus
Fungus
and
Fungus
Fungus
Fungus
Fungus
Virus
Nematode
Fungus
Alternaria sp.
Ascochyta phaseolarum
Cercospora canescens
Corynespora cassiicola
Fusarium sp.
Athelia rolfsii
Phoma exigua
Sphaerotheca fuliginea
Thanatephorus cucumeris
Uromyces vignae
Cowpea mosaic virus
Meloidogyne javanica
Botrydiplodia theobromae
Fungus
Fungus
Possibly virus
Cercospora canescens
Oidium sp.
Bean-common
Leaf spot
Leaf spot
Anthracnose
Angular leaf spot
Collar rots
Leaf blight
Leaf spots
(on old leaves)
Floury white mould
Rust
Mosaic
Root knot
Bacterial blight
On seeds
Broad bean
Leaf spot
Leaf spot
Sooty mould
Leaf blight
Leaf spot
Cluster bean (Guar bean)
Powdery mildew
Cowpeas (and snake bean)
Leaf spot
Leaf spot
Leaf spot
Leaf spot
Root rot
Leaf spot
Powdery mildew
Leaf blight
Rust
Mosaic
Root knot
Storage rot
Green gram bean
Leaf spot
Powdery mildew
Yellow mosaic
Jackbean
Leaves small & distorted
Kudzu
Yellow mould
False rust
Leaf spot
Lablab bean
Leaf spot
Angular leaf spot
Tip wilt
Leaf blight
Small twisted leaves
Root knot
Lima bean
Probably virus
Fungus
Fungus
Mycovellosiella puerariae
Synchytrium minutum
Fungus
Fungus
Fungus
Fungus
Probably virus
Nematode
Ascochyta dolichi
Cercospora canescens
Choanephora cucurbitarum
Thanatephorus cucumeris
161
Meloidogyne arenaria
Rust
Concentric spots
Root knot
Fungus
Fungus
Fungus
Phakopsora vignae
Phoma exigua
Meloidogyne incognita
Leaf spot
Leaf spot
Leaf spot
Leaf spot
Collar rot
Mosaic
Root knot
Fungus
Fungus
Fungus
Fungus
Fungus
Virus
Nematode
Alternaria sp.
Phoma exigua
Phyllosticta sp.
Myrothecium roridum
Athelia rolfsii
Leaf spot
Leaf spot
Brown mould
Powdery mildew
Leaf spot
Mosaic
Root knot
Dry rot seeds
Fungus
Fungus
Fungus
Fungus
Fungus
Probably virus
Nematode
Fungus
Ascochyta pinodes
Mycosphaerella pinodes
Fulvia fulvum
Oidium sp.
Phyllosticta sp.
Seedling death
Collar rot
Fungus
Fungus
and
Fungus
Fungus
Fungus
Fungus
Fungi
and
Fungus
Fungus
Fungus
and
Fungus
Bacterium
Virus
Virus
Virus
Aspergillus niger
Athelia rolfsii
Botryodiplodia theobromae
Leptosphaerulina trifolii
Cercosporidium personatum
Colletotrichum sp.
Leptosphaerulina trifolii
Mycosphaerella arachidicola
Mycosphaerella berkeleyi
Phomopsis sp.
Puccinia arachidis
Pythium sp.
Rhizoctonia
Thanatephorus cucumeris
Pseudomonas solanacearum
Leaf spot
Pink disease
On seeds
Fungus
Fungus
Fungus
and
and
and
and
and
Mycovellosiella cajani
Phanerochaete salmonicolor
Aspergillus niger
Chaetomium sp.
Curvularia lunata
Fusarium solani
Penicillium sp.
Nigrospora oryzae
Blossom blight
False rust
Rust
Root knot
Fungus
Fungus
Fungus
Nematode
and
Fungus
and
and
and
and
Choanephora cucurbitarum
Synchytrium phaseoli
Uromyces sp.
Meloidogyne arenaria
Meloidogyne javanica
Aspergillus niger
Penicillium sp
Periconia byssoides
Rhizopus nigricans
Verticillium sp.
Fungus
and
Ascochyta sp
Cercospora canescens
Mung bean
Meloidogyne incognita
Pea
Meloidogyne incognita
Penicillium sp.
Peanut
Large leaf spot
Leaf spot
Leaf spot
Leaf spot and pod rot
Leaf spot
Collar rot
Rust
Root rot
Blackening stems
Bacterial wilt peanut
Mosaic
Leaf mottle
Mild mottle
Marginal leaf chlorosis virus
Cowpea mild mottle virus
Pigeon pea
Rice bean
On seeds
Soya bean
Leaf spot
Phakopsora pachyrhizi
Xanthomonas campestris
Rust
Bacterial leaf spot
Leaf distortion
Mosaic
Yellow mosaic
Root knot
Fungus
Bacteria
Possibly virus
Possibly virus
Virus
Nematode
Flower blight
Anthracnose
Leaf spot
Collar rot
Fungus
Choanephora cucurbitarum
Fungus
Colletotrichum lindemuthianum
Fungus
Didymella sp.
Fungus
Macrophomina phaseolina
and
Fusarium spp.
and
Thanatephorus cucumeris
Fungus
Meliola erythrinae v. psophocarpi
Fungus
Oidium sp.
Fungus
Pseudocercospora psophocarpi
Fungus
Synchytrium psophocarpi
Possible virus
Possible mycoplasma like organism
Nematode
Meloidogyne incognita
and
Meloidogyne javanica
Meloidogyne sp.
Winged bean
Sooty mould
Powdery mildew
Leaf spot
False rust
Leaf curl
Little leaf
Root knot
Yard-long bean (Snake bean)
Leaf spot
Powdery mildew
Rust
Mosaic
Choanephora cucurbitarum
Sphaerotheca fuliginea
Uromyces vignae
Cowpea mosaic virus
Fungus
Fungus
Fungus
Virus
Floury white mould bean
False rust Kudzu
Leaf spot Aila
Leaf spot winged bean
163
Insect pests of bean family plants
Aibika leaf miner
Acrocercops sp. Also damages soybean.
Bean leaf rollers Lamprosema indica and Lamprosema diemenalis. Larvae
tie leaves of beans together with silken threads. Then they eat away the leaf
tissue. They damage peas, peanut, soybean, winged bean, cowpea, snake
bean, mung bean, velvet bean, pigeon pea and other beans. They feed on
most species of grain and vegetable legumes in Papua New Guinea.
Bean pod borer Maruca testulalis These insects can cause serious damage to
the pods and seeds of most beans. They damage Lima, snake, mung, adzuki,
rice bean, snake bean, cowpea, winged bean, soybean, velvet bean, and
pigeon pea. The larvae bore into the young pods and can enter the stems. The
hole where they enter the plant is normally filled with chewed up plant
material. They also eat other plant parts.
Cacao armyworm Tiracola plagiata. On lima beans, common beans,
winged bean. The larvae eat young soft growing parts of the plants and can
also eat weeds and other bush trees.
Cluster caterpillar Spodoptera litura. They damage a range of crops beans including winged bean, peas, peanuts. Quite often the damage is only
slight but in some seasons they can do extensive damage. They move
between crops and the numbers depend on the climatic conditions.
Coconut spathe moth Tirathaba rufivena and also Tirathaba ignevena. The
larvae attack beans.
Coffee leaf roller Homona coffearia. Damages by eating leaves and rolling
up leaves. Also damages soybean, pea, snake bean, velvet bean, peanut,
mung bean. It is more serious in the highlands.
Common grass blue butterfly Zizina otis. The larvae feed on the leaves of
a range of beans including pigeon pea, snake bean, soybean and winged bean.
Corn earworm Heliothis armigera. The larvae feed on leaves and fruit.
They damage a range of plants, pigeon pea, garden peas, beans. Rain helps
the pupae develop and warm moist weather makes the pest worse.
Cotton semi-looper Anomis flava. The larvae of this moth can often damage
black velvet bean throughout the year. They eat the tissue of leaves leaving
veins.
Green looper Chrysodeixis chalcites. Larvae also damage beans, and
legumes. Reported snake bean, eating leaves. They can completely eat the
soft tissue of leaves of soybean.
Pea Blue butterfly Lampides boeticus. The larvae feed on flowers and bore
in the pods of a number of legumes including snake beans, pigeon pea, mung
bean, cowpea, peas, winged bean, pigeon pea and Crotalaria.
Rice armyworms Mythimna loreyi & Mythimna separata. They are reported
damaging winged bean leaves.
Winged bean blotch miner Leucoptera psophocarpella. Damages winged
bean leaves on the underside of leaves.
Phyllocnistis sp - a leaf miner also listed as occurring on winged bean
Bean weevil Acanthoscelides obtectus. It damages the seeds of all beans
both in the field and in storage. The larvae feed inside the seeds then leave
round holes as the adults leave. In the field the damage by the very small
larvae is scarcely noticed and the main damage is done after harvest. They
are favoured by warm dry conditions.
Black flea beetle Arsipoda tenimberensis. This insect damages common
bean and soybean and probably some other plants. The insect causes
characteristic damage. It is widespread but the damage is normally not
important.
Horned weevil Apirocalus spp. Occur up to about 1600 m altitude. Damage
to peanut, mung bean. It mainly attacks growing points and soft shoots. It
chews the leaves eating holes and this is often called shot hole damage.
Other insects do similar damage. The damage is often not serious.
Cassena papuana Chrysomelidae beetle. Leaf beetles attack beans including
common bean, mung bean, soybean, snake bean, broad bean. Important
occasionally.
Psylliodes sp nr fulvipes Chrysomelidae beetle. Feeding on snake bean.
Cause minor damage to leaf epidermis.
Leaf eating ladybird Henosepilachna signatipennis and Henosepilachna
haemorrhoea (Epilachna signatipennis also eats bean leaves.) Both the
larvae and adults eat the leaves, young fruit and flowers of plants. They eat
common bean, winged bean, mung bean, soybean, and a number of other
legumes. They tend to prefer higher humidity. Many ladybird beetles look
similar but are in fact good insects because they feed on aphids. These
Epilachna species have a covering of fine hairs that helps tell them from the
good species.
Monolepta beetles Monolepta spp. They damage leaves and flowers of
mungbeans. They feed on young shoots.
Pumpkin beetles Aulacophora spp. They damage beans including common
bean, mung bean, soybeans, peanuts, broad beans.
Shot hole weevils Oribius spp. They feed on a wide range of plants.
Tangets are one. They also eat snake bean, mung bean, lima bean, and
others. They chew irregular shaped holes.
Amblypelta bugs Amblypelta spp. They suck sap and secrete a toxic saliva.
A few insects can cause extensive damage. They attack mung beans, winged
bean. They can cause plants to wilt and fruit to drop off.
Cacao mirid Helopeltis clavifer. They have piercing mouthparts that secrete
a toxic substance that produces a dead spot on the plant. They can cause the
death of the terminal bud and growing shoot of plants. One insect can make
50 feeding punctures a day. Young fruits can die and older fruits can be
deformed. They have been recorded damaging 25 species of plants in PNG.
These include snake bean, and Leucaena. The insects occur from sea level up
to 1670 m altitude.
Cowpea aphid Aphis craccivora These aphids are often found feeding on
snake beans. They rarely cause much damage. Large numbers get on
cowpea in the wet season. They can also attack other beans including winged
bean, mung bean and lima bean. They cluster in large numbers near the tips
of stems and shoots and their feeding causes these parts to be deformed.
Plants can be stunted and wilt. Their importance for spreading viruses is not
known. They can spread cowpea mosaic virus. They also damage peanuts.
They can be spread in the wind.
Foxglove aphid Aulacorthum solani Reported on beans. It attacks plants in
the potato/tomato family spreading virus diseases.
Grass bug Alticus tibialis Sap feeder on mung bean and soybean. Can also
feed on peanuts.
Green peach aphid Myzus persicae. It does damage by direct feeding and
by transmitting viruses. Often the insect is scarcely noticed and the main
result is the diseases it spreads. The direct feeding damage cannot normally
be seen. It attacks a very large number of plants and spreads a very large
number of virus diseases. It damages beans.
165
Green vegetable bug Nezara viridula. They damage a number of vegetables
and fruits by sucking the sap. They damage beans, including winged bean,
rice bean, soybean, broad bean, mung bean, snake bean. Both the young
nymphs and the adults suck sap. The sucking of the sap causes plants to wilt.
Also it can cause lumps and deformed fruit. The insects give off a smell that
affects food to eat. It is a more serious pest in the lowlands.
Melon aphid Aphis gossypii. Large numbers can cause leaves to curl and
this can stunt the plant growth. It can reduce the numbers of flowers and fruit
formed. The aphids also release a sticky substance called honeydew and this
often encourages the growth of sooty moulds. Aphids transmit disease. They
damage winged bean.
Paddy bugs Leptocorisa spp. Bugs can feed on beans.
Pod sucking bug Riptortus spp. It can cause severe damage to winged
beans, snake beans, mung beans, soybeans, lima beans, peas, common bean
and probably other beans. It sucks the pods. They occur throughout the year.
Stink bug Plautia brunneipennis. Reported sucking sap of snake bean.
Sugarcane aphid Aphis sacchari. It can damage beans. Sugarcane is the
major hosts.
Bean fly Ophiomyia phaseoli. Plants turn yellow and stems become swollen
and cracked and break off in wind. This insect commonly does serious
damage during dry seasons. 8 to 10 maggots per plant can kill a seedling.
Common bean is very easily damaged. It is probably the most important
bean pest. It has been recorded on common bean, snake bean, soybean, mung
bean.
Shootfly Atherigona orientalis Larvae also attack fruit of common bean.
Phaneroptera brevis Phaneroptera brevis. It attacks beans including winged
bean, pigeon pea, peas, by eating the leaves. It is often found in shady
places.
Red spider mite Tetranychus marianae. It commonly attacks leaves of peas,
dwarf beans and winged beans. Other plants can also be attacked. They live
on the lower surfaces of leaves often near veins. Yellow spots are produced
then drying of the leaves occurs. They suck sap and leave a fine silk
webbing. They get worse in hot dry weather. They can cause heavy damage
to beans.
Other bean insect pests:
Adoxophyes tetraphracta Meyrick
leaf roller
Larvae reported damaging leaves velvet bean.
Adoxophyes sp
leaf roller
Reported damaging peanuts, soybean, peas.
Anticarsia irrorata F.
Noctuidae (LEP.)
Reported eating leaves of mung bean and snake bean. Also known to attack velvet bean.
Araecerus fasciculatus Degeer. Coffee weevil.
Reported damaging winged bean.
Araeocorynus cumingi Jekel
Anthribidae (COL.)
Reported damaging winged bean.
Bothrogonia sp
Cicada bug
Sap-sucker of kidney bean.
Brachyplatis papuus Guer.
Pentatomidae (HEM.)
Recorded damaging beans. Also damages some tree legumes.
Brachyplatys sp
Pentatomidae (HEM.)
Recorded sucking pod of velvet bean.
Caedius demeijerei Geb.
Tenebrionidae (COL.)
Reported damaging beans especially young seedlings to which they can cause considerable damage. The adults are
found on the ground under beans.
Chauliognathus waroensis Wittmer
Cantharidae (COL.)
Reported damaging bean leaves in highlands.
Coelophora inaequalis F.
Coccinellidae (HEM.)
Reported damaging soybean. Leave circular holes in leaves. Normally predator of aphids.
Colposcelis vignaphila Bryant
Chrysomelidae (COL.)
On common bean.
Demonax collaris Pascoe
Cerambycidae (COL.)
Reported damaging soybean in highlands.
Epilachna signatipennis Boisd.- leaf eating beetle
Reported damaging rice bean, common bean, cowpea, lima bean.
Erythroneura sp.
Cicadellidae [Jassidae](HEM.)
Adults and nymphs feeding on underside of leaves of winged bean. Damage sometimes severe.
Euproctis sp
Lymantriidae (LEP.)
Reported eating leaves of winged bean.
Euricania discigutta (Walk.)
Plant hopper
Reported damaging beans.
Euricania villica
plant hopper
Reported sucking sap of common bean.
Halticus minutus Reuter
flea hopper.
Reported on peanuts and beans. Sucking sap of common bean, soybean.
Homeoxipha fuscipennis
Gryllidae (0RTH.)
Reported chewing leaves of winged bean.
Hyposidra talaca (Wlk.)
Geometridae (LEP.)
Eating leaves of common bean. The caterpillar attacks many woody plants. The larvae are brown and bear rows of
white spots across the body. The mature larvae lower themselves on threads and pupate 2-4 cm deep in the soil. The
eggs are iridescent and in clusters. One female may deposit several hundred eggs. A life cycle takes 2.5 to 3.5 months at
1700 m altitude.
Megalurothrips usitatus Bagnall
Thrip
- on mung bean, peanut, soybean, lima bean.
Melacanthus argineguttatus
Alydidae (HEM.)
Recorded sucking pods of mung bean.
Nyctemera baulus Boisduval
Arctiidae (LEP.)
Larvae damaging winged bean leaves.
Nysius epiensis China
Lygaeidae (HEM.)
Reported damaging beans. Adults cause yellow spotting of foliage. Also on peanuts.
Orchamoplatus mammaeferus (Quanitance & Baker) Aleyrodidae
On beans.
Pachybrachius nervosus Horv.
Lygaeidae (HEM.)
Reported causing yellow spotting on beans.
Piezodorus rubrofasciatus Fab.
Pentatomidae (HEM.)
Sucking pods of mung bean.
Plautia brunneipennis
Stink bugs
Reported damaging snake bean.
Prosoplus oblique plagiatus Breuning
Cerambycidae (COL.)
Reported on pods of winged bean.
Rhinoscapha funebris Chev.
Weevil
Reported on soybean.
Rhyparida coriacea Jac.
Chrysomelidae (COL.)
Reported feeding on leaves of mung bean.
Rhyparidella wauensis
Reported adults eating leaves of soybean, mung bean, broad bean.
Ropica honesta Pascoe
Cerambycidae (COL.)
Reported damaging dry winged bean pods.
Zygina sp.
Cicadellidae (HEM.)
Reported on winged bean leaves.
167
Cabbage family
Several different plants in the cabbage family are grown for food in Papua New Guinea.
Some of these like broccoli, brussels sprouts, kohl rabi, and cauliflower are mostly only grown by
Europeans or for sale to Europeans. Others like European cabbage have become very popular and
common in the high areas in the highlands. Some plants in this family have also been grown for
many years or are probably traditional Papua New Guinea food plants. Some of these do not have
common English names eg Nasturtium schlechteri. Others like watercress have been introduced
into highland creeks and in some areas almost grow naturally. Chinese cabbage is popular and
common in coastal areas. Others like Chinese radish and English radish are often only grown for
sale. Only some of these plants will be described here.
Cabbage
Scientific name: Brassica oleracea
How is it grown?
One of the interesting things about the way this crop is grown in Papua New Guinea is that
seed are not regularly used and people grow it from shoots off the old stem. When a cabbage is
harvested, the top head part of the cabbage is cut off and the stalk is left growing in the ground.
This produces a ring of new shoots and these are broken off and planted. This is a good cheap way
of getting new plants and works well as long as the old plant does not have some diseases that are a
problem with cabbage.
Chinese cabbage
Two main kinds of Chinese cabbage are grown in Papua New Guinea. One is a more tightly
headed cabbage and is more commonly seen in the highlands. The other is a more open leafy
cabbage and is more common on the coast. They have slightly different scientific names.
Pak choi
Brassica campestris ssp. pekinensis
and
Petsai
Brassica campestris ssp. chinensis
Nasturtium schlechteri
See Rorippa - under greens
169
Diseases of the Cabbage family (Brassicaceae)
Broccoli
Black rot
Root knot
Fungus
and
Bacteria
Nematode
Alternaria brassicae
Botrytis sp.
Xanthomonas campestris
Meloidogyne sp.
Black leaf spot
Black rot
Fungus
Bacteria
Alternaria brassicicola
Xanthomonas campestris
Black leaf spot
Leaf spot
Ring spot
Downy mildew
Black rot
Soft rot
Collar rot
Damping off
Root knot
Fungus
Fungus
Fungus
Fungus
Bacteria
Bacteria
Fungus
Fungus
and
Nematode
Alternaria brassicicola
Colletotrichum sp.
Mycosphaerella brassicicola
Peronospora parasitica
Xanthomonas campestris
Erwinia carotovora subsp. carotovora
Thanatephorus cucumeris
Pythium sp.
Rhizoctonia sp.
Meloidogyne incognita
Black leaf spot
Leaf spot
Black rot
Root knot
Fungus
Fungus
Bacteria
Nematode
Alternaria brassicicola
Cercospora brassicicola
Xanthomonas campestris
Meloidogyne sp.
Grey leaf spot
Black leaf spot
Leaf spot
Wet rot
Downy mildew
Leaf wilt (Soft rot)
Black rot
Seedling wilt
Fungus
Fungus
Fungus
Fungus
Fungus
Bacteria
Bacteria
Fungus
Alternaria brassicae
Mycosphaerella brassicicola
Septoria sp.
Choanephora cucurbitarum
Peronospora parasitica
Erwinia caratovora
Xanthomonas campestris
Fusarium oxysporium
Leaf spot
Fungus
Alternaria raphani
Leaf spot
Fungi
Black rot
Bacteria
Alternaria brassicae
Alternaria brassicicola
Xanthomonas campestris
Grey leaf spot
Brussels sprouts
Cabbage
Cauliflower
Chinese cabbage
Radish
Turnip
Insect pests of cabbage family plants
Beet webworm Hymenia recurvalis (Fab.) Pyralidae LEPIDOPTERA
The caterpillars roll up the leaves of a number of plants and form a web.
They eat the leaves. They damage Chinese cabbage. It feeds on the underside of
leaves.
Black cutworm Agrotis ipsilon (Hufnagel) Noctuidae LEPIDOPTERA
The caterpillars cut off seedlings at ground level. They do this damage at
night. Damage occurs in a range of plants grown from seed including Rorippa sp.
cabbage. They tend to get worse in areas that have been low-lying damp areas
especially where there have been many weeds present.
Cabbage cluster caterpillar Crocidolomia binotalis Zeller Pyralidae
LEPIDOPTERA These caterpillars eat holes in the leaves of a number of plants in
the cabbage family. They leave dark chewed-up lumps on the leaves. They can
regularly cause 90% damage to the more leafy types. The hearts of cabbage can
often be completely destroyed. Plants damaged include cabbage, Chinese cabbage,
kohl rabi, broccoli, turnip, radish and Nasturtium schlechteri. The insect avoids
light so eats on the underside of leaves.
Cacao armyworm Tiracola plagiata Walk Noctuidae LEPIDOPTERA
Some of the crops attacked include cabbage, cauliflower. The larvae eat
young soft growing parts of the plants and can also eat weeds and other bush trees.
The insect tends to build up on trees like leucaena shade or other large areas of one
crop then spread in plague numbers into surrounding gardens.
Cluster caterpillar Spodoptera litura (Fab) Noctuidae LEPIDOPTERA
They damage a range of crops - cabbage, Brussels sprouts, kohl rabi. Quite often
the damage is only slight but in some seasons they can do extensive damage. They
move between crops and the numbers depend on the climatic conditions.
Corn earworm Heliothis armigera (Huebner) Noctuidae LEPIDOPTERA
The larvae feed on leaves and fruit. They damage a range of plants,
including cabbage. Rain helps the pupae develop and warm moist weather makes
the pest worse.
Diamond back moth Plutella xylostella (L.) Plutellidae LEPIDOPTERA
The caterpillars eat irregular shaped holes on the leaves of cabbage family
plants. They are very common. The larvae drop from the plant on silken threads
when they are disturbed. They damage cabbage, turnip, broccoli, kohl rabi, brussels
sprouts, chinese cabbage, Nasturtium schlechteri, and possibly other plants in the
cabbage family. The moth tolerates a wide range of climates but gets worse in hot
dry areas.
Green looper Chrysodeixis chalcites (Esp.) Noctuidae LEPIDOPTERA
Larvae commonly eating cabbage leaves. Also damages cabbage family
plants.
A semi looper, Phytometra orichalcaea (F.) (LEP.) [Probably syn. Plusia
orichalcaea L.] is reported on Chinese cabbage, turnip and Brussels sprouts. It is an
attractive golden-coloured moth.
Horned weevil Apirocalus spp. Curculionidae COLEOPTERA
Occur up to about 1600 m altitude. Damage to cabbage. It mainly attacks
growing points and soft shoots. It chews the leaves eating holes and this is often
called shot hole damage. Other insects do similar damage. The damage is often not
serious.
Grass bug Alticus tibialis Reut Miridae HEMIPTERA
Sap feeder on Chinese cabbage.
171
Green peach aphid Myzus persicae Sulzer Aphididae HEMIPTERA
It does damage by direct feeding and by transmitting viruses. Often the
insect is scarcely noticed and the main result is the diseases it spreads. The direct
feeding damage cannot normally be seen. It attacks a very large number of plants
and spreads a very large number of virus diseases. It is always present on cabbages
in the highlands.
Cabbage leaf miner Lyriomyza brassicae (Riley) Agromyzidae DIPTERA
The larvae burrow into the leaves of cabbage, Chinese cabbage, radish,
broccoli, and turnip. It probably damages other cabbage family plants.
Phaneroptera brevis Tettigoniidae ORTHOPTERA
It attacks Chinese cabbage, cabbage, radish, brussels sprouts by eating the
leaves. It is often found in shady places.
Minor pests
Adoxophyes sp
Tortricidae (LEP.) -leaf roller
Reported damaging chinese cabbage.
Araecerus sp. (See Oxyderes )
Anthribidae (COL.)
Related to coffee bean weevil. Damaging cabbage.
Colgar tricolor Dist.
Flatidae (HOM.)
Reported damaging chinese cabbage, cabbage; Sap sucker.
Coproporus sp.
Staphylinidae (COL.)
Reported damaging cabbage.
Diachrysia orichalcaea Fab
Noctuidae (LEP.)
Reported doing damage to cabbage.
Euricania discigutta (Walk.)
Ricaniidae (HEM.)- plant hopper
Reported damaging cabbage, chinese cabbage.
Halticus minutus Reuter
Miridae (HEM.)-flea hopper.
Reported sucking sap of chinese cabbage and radish
Nyctemera baulus Boisduval
Arctiidae (LEP.)
Larvae damaging leaves of cabbage.
Odontomyia sp
Stratiomyiidae DIPT.)
Larvae in cabbage.
Onthophagus sp nr papuensis Harold
Scarabaeidae (COL.)
On cabbage.
Phormesa sp.
Colydiidae (COL.)
On cabbage.
Spilosoma owgarra Bethune-Baker
Arctiidae (LEP.)
Larvae feeding on cabbage. Reddish brown "bear caterpillars". Eat various
vegetables.
Valanga sp.
Acrididae (ORTH.)
Giant grasshoppers reported causing damage to Chinese cabbage.
Capsicum and chilli
Name: Capsicum
Also called red and green peppers
Scientific name: Capsicum annum
The plant
This is a plant that grows from seeds each year. It grows up to 1.5 metres high and produces
several branches. The flowers occur singly in where the leaves join the stalk and mostly the flowers
are yellow. The fruit come in various shapes from round to long. The larger types can have fruit up
to 8 cm across. They also vary in colour from green to red to yellow. Inside the fruit there are many
seeds.
In Papua New Guinea the capsicum grows well at sea level but will also grow up to
about1900 metres altitude. It is killed by frost.
Growing capsicums
They are grown from seed. The seed can be collected from mature fruit. It is possible to
plant the seed directly in the garden or the plants also transplant quite easily. Seedlings are normally
transplanted about one month after seed are planted. They need a well drained and fertile soil. It is
often best therefore to plant capsicums on raised beds in the garden especially in wet areas.
Fruit can be harvested after about 3 or 4 months. From then on regular harvests of fruit can
be made for about one year.
173
Pests and diseases
Capsicum insect pests
Atherigona orientalis Schiner
Carpophilus maculatus Murray
Bactrocera bryoniae (Tryon.)
Bactrocera musae (Try.)
Bactrocera trivialis Drew
Euproctis sp.
Heliothis armigera (Huebner)
Homeoxipha fuscipennis
Macrosiphum euphorbiae (Thomas)
Pinnaspis strachani (Cooley)
Planococcus pacificus Cox
Plautia brunneipennis
Pseudaulacaspis pentagona (Targioni)
Pulvinaria ubicola (Cockerell)
Thrips tabaci Lind.
Silba sp.
Muscidae (DIPT)
Nitidulidae (COL)
Tephritidae (DIPT)
Tephritidae (DIPT)
Tephritidae (DIPT)
Lymantriidae (LEP)
Noctuidae (LEP)
Gryllidae (ORTH)
Aphididae (HEM)
Diaspididae (HEM)
Pseudococcidae (HEM)
Pentatomidae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Thripidae (THYS)
Lonchaeidae (DIPT)
Shootfly
Damaging fruit
Fruit fly
Banana fruit fly
Fruit fly larvae destroying fruit
Reported eating leaves
Corn earworm
Reported chewing leaves
Potato aphid
Armoured scale
Mealybug
Stink bugs
White scale
Soft scale
Onion thrips
Larvae boring into fruit
Capsicum diseases
Leaf spot
Collar rot
Fruit rot (Anthracnose)
Fruit rot
Leaf blotch
Wilt
Root rot
Bacterial wilt
Storage rot
Bacterial leaf spot
Leaf distortion
Root knot
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
and
Bacteria
Bacteria
Bacteria
Virus
Nematode
Alternaria sp.
Athelia rolfsii
Glomerella cingulata
Curvularia sp.
Thanatephorus cucumeris
Fusarium solani
Pythium sp.
Fusarium sp.
Pseudomonas solanacearum
Erwinia carotovora
Xanthomonas campestris pv. vesicatoria
Possibly potato virus y
Meloidogyne incognita
As food
The leaves of capsicum or peppers can be eaten and are good quality food. They maintain a
good texture when cooked and have a mild spicy flavour.
The fruit can be eaten raw. Normally they get hotter or more spicy as they get ripe and red.
Some kinds especially the longer types are normally hotter. They can also be cooked or used to add
flavour to other food dishes. Normally the central part of the fruit and the seeds are removed before
eating.
Chilli
Scientific name: Capsicum frutescens
English name: Chilli
Tok Pisin name: Sili
Tok Ples Kuanua: Lobo
The plant
This small shrub is about one metre tall and continues to grow for several years. Plants
often occur self-sown from seeds dropped by birds. The flowers are pale green and about 8 mm
across. The chilli has several fruit in a cluster on a stalk. They change from green to yellow to red
as they ripen. The fruit are about 2 cm long.
Growing chilli
Chilli will grow from sea level to about 1800 metres altitude. It cannot stand frost. The
seeds are very small and are best sown in a nursery and then the young plants transplanted when
they have 4 or 5 leaves. (After 3 or 4 weeks). They can be planted at about 80 cm apart. Pruning
out the tops of the bushes increases the branching of the plant.
Chilli insect pests
Horned weevil Apirocalus spp. CurculionidaeCOLEOPTERA
Green peach aphid Myzus persicae SulzerAphididaeHEMIPTERA
Banana fruit fly Bactrocera musae (Try.) and Bactrocera bryoniae (Try.) Tephritidae DIPTERA
Idopsis coerulea Faust. Curculionidae (COL.)
Causing minor shot hole damage.
Red twig borer Zeuzera coffeae Nietner Cossidae (LEP.) Reported damaging chilli plant by boring into stems. Larvae
are red to violet brown often with yellow rings. They bore into woody stems. A circular tunnel is formed under the
bark. The end of the branch dies. The moths fly at night. Up to 1000 eggs per female. Development takes 4-5.5
months. Control is seldom necessary.
Scales and mealy bugs
Aonidiella aurantii (Maskell)
Icerya seychellarum (Westwood)
Coccus hesperidium Linnaeus
Parasaissetia nigra (Nietner)
Pulvinaria psidii Maskell
Pulvinaria ubicola (Cockerell)
Saissetia coffeae (Walker)
Chilli diseases
Fruit rot
Leaf & fruit blotch
Root knot
Glomerella cingulata
Thanatephorus cucumeris
Meloidogyne incognita
Fungus
Fungus
Nematode
175
As food
The small red fruit are very hot to eat due to a chemical called capsaicin. They are therefore
used to add spice and flavour to other foods.
The leaves can be eaten cooked and are nice tasting leafy greens.
Leaves
Fruit
Moisture
%
82
91
Energy
cals
53
/ 100 g edible portion
Protein Calcium
Iron
g
mg
mg
5.8
246
1.4
provitA
!g
68
provitC
mg
Zinc
mg
Corn
Tok Pisin: Kon
Scientific name: Zea mays
The corn plant
The corn plant is a grass family plant that can grow up to 2 or 3 metres tall. It has prop
roots near the ground and these help to hold the plant up.
When it is nearly full grown it develops a cob (female flower) in the place where the
leaves join the stem. It also grows a male flower at the top of the plant. When the cob is mature,
the plant dies.
Sometimes corn is called maize. This is really just another name for the same plant. But
there are special types of corn like sweet corn and pop-corn.
The clump of corn seeds that grows on a stalk is called a corncob or an ear of corn. As it
is growing, a stringy group of hairs comes out the top of the cob. These are called the tassel.
177
Getting corn seed
One of the important things for growing good corn is to get some good seed.
Corn has two types of seed. One is called hybrid seed and it can produce very well if it is
grown under very good conditions. But you can't save your own seed to re-plant. This is because
the plants which come up may not be very good plants at all. Hybrid seed needs to be produced by
a specialist. So you must buy hybrid seed from a seed producer.
The other kind of corn seed is called open pollinated. It is the kind most people in Papua
New Guinea use. They save their own seed to re-plant. But most people in village gardens run into
a problem when they save their own corn seed. The plants gradually get smaller and smaller until
only very small plants with very small cobs are produced. These small cobs are nice and sweet but
they don't provide much food. The reason for this is that in a village garden there is often only a
few corn plants. Also the plants are often widely spaced and people just save one or two cobs to
use for seed. So what happens is that the corn plants inbreed. Instead of pollen going around
between several plants and then seed being saved from a few different cobs the pollen just goes to
the flower on the same plant or to a few plants close by. So the seed becomes inbred and produces
smaller plants.
The way to stop this is:
1. Save seed from a large corn garden. (Over 200 plants that are getting ready at the same
time and close together in the same garden.)
2. Collect your seed from a few different cobs and mix the seed together before planting.
If these two rules were followed when saving corn seed in a village a big improvement
could be made in how much food is produced from corn plants.
A good corncob
As well as making sure that seed is looked after and collected properly, it is only sensible
to start with a good type of corn that is suited to your area. Often the seeds that you buy in packets
from stores have come from another country and are not suitable for Papua New Guinea. The
Agricultural Officers have picked out some good kinds of corn for Papua New Guinea. You can get
some seed from your didiman to start you off.
Planting corn
Corn needs fairly good soil. So there is no point in planting it in a fairly old kaukau
garden. It can either be put in a freshly cleared garden or one where the soil fertility has been built
up, such as around a house.
Most village people plant 2 or 3 seeds in the one hole. This is because they know that an
insect called the black cutworm will probably eat off one or two, so one may survive. If all the
plants grow and are not killed then the smallest plants are often pulled out. This is one way of
dealing with seedling losses like cutworm damage. Some village people have found another way of
stopping cutworm damage. They plant the seed and then put a bamboo container around it to
protect it. People who have old fish tins use them for the same purpose after they have cut both the
top and the bottom out of the tins.
The other thing that can commonly be seen is a person carrying a corncob and picking the
seeds off to drop in the holes as they are made. This is the wrong way to mix and collect corn seeds
and the reason has been explained above.
A bamboo ring to protect
young corn plants from
cutworms.
Why do corn leaves go dry?
Sometimes the leaves of corn, instead of remaining dark green, get dry brown marks.
This can be either due to disease or due to the plant running out of the nutrients it needs to grow.
(Old plants also turn brown naturally as they die off.) It is possible to learn to tell the difference
between these marks.
Nitrogen deficiency
One of the commonest nutrients that corn plants run short of is nitrogen. A plant that is
short of nitrogen has the older bottom leaves going dry. The dry brown mark is a distinctive shape.
It starts at the tip of the leaves and goes in a V shape down the centre of the leaves.
A corn leaf showing nitrogen deficiency
179
Potassium
Plants that are running out of the nutrient potash go dry and brown along the edges. Also
the leaves may be a lighter green than normal and sometimes they are twisted. Cobs get thinner at
the top end.
A corn leaf showing potash shortage
Phosphorus
It is not as easy to be sure of a plant that is getting short of the other important nutrient
called phosphorus. Plants short of phosphorus are smaller and the leaves are bluish green with red
marks. But some leaves can be naturally reddish blue and leaves can change to these colours for
other reasons.
Potash deficiency
Nitrogen deficiency
Phosphorus
Potassium
Nitrogen
Diseases
Diseases are different from these marks because a disease is caused by a small, living
thing and it is actually growing on or inside the plant. The things causing disease are very small but
it is often possible to see the marks due to the disease.
Corn diseases
Leaf spot
Leaf spot
Tropical rust
Rust
Downy mildew
Leaf spot
Leaf blotch
Leaf spot
Leaf blight
Blister smut
Head smut
Irregular bleached areas
Collar rot
Fungus
Fungus
Fungus
Fungus
Fungus
and
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Bipolaris zeae
Curvularia lunata
Puccinia polysora
Puccinia sorghi
Peronosclerospora sacchari
Peronosclerospora sorghi
Phoma sorghina
Setosphaeria turcica
Cercospora sorghi
Cochliobolus heterostrophus
Ustilago zeae
Sphacelotheca reiliana
Thanatephorus cucumeris
Pythium butleri
Diseases
In the highlands one of the commonest leaf diseases on corn produces long yellow to
brown spots on the leaves. It is called corn leaf blight and is due to a fungus. Often the spots start
as pale soft watery looking marks that turn yellow and later brown and dead. The spots can join
and the leaf dies early. In moist weather these spots produce dark green spores (or "seeds") in the
centre of the spots. These spores can blow in the wind onto other corn plants. Also they can stay
alive on old corn plants for many months. Therefore it is important to move corn to a new or
different garden to help avoid the disease. As well it is important to get rid of old corn plants, to
use clean seed and to look for kinds of corn that get the disease less.
A corn leaf with spots due to corn leaf blight
Corn rust
Two fungi cause yellow or light red looking lumps on the leaves of corn. These diseases
cause the leaves to get dry quickly and therefore smaller cobs are produced. Getting rid of old
diseased plants helps reduce the damage to new corn plants. As well, a lot of the corn seed given
out by didimen throughout Papua New Guinea in the last few years is of kinds that get this disease
less.
A corn leaf showing
small raised red spots
of rust
181
Corn also gets some other leaf diseases but these have not been seen very often in the
Highlands. White long stringy patterns on corn leaves can be due to downy mildew fungus, a virus
or magnesium deficiency.
Corn blister smut
Diseases don't only get on leaves.
One of the more serious fungal diseases that
grows on corn in the Highlands is called corn
blister smut. It grows on the cob but can also
get on the leaves. It causes large grey
swellings and lumps on the corncob. These
lumps are filled with powdery grey spores and
there is a silvery skin over them. It completely
spoils the cob.
The spores can live in the ground for
many years. This makes it hard to avoid the
disease once it gets into an area. The disease
can be controlled by using clean seed, as the
disease can be on the seed. As well it is
important to pull out and burn any plants you
see with the disease. Corn should also be
planted into new or clean gardens.
A corncob
showing blister
smut disease
Poor pollination
Sometimes corncobs can be poor for other reasons. Cobs can be harvested on which only
some of the seeds have developed. This is because the other seeds were not fertilised by pollen.
The reasons it was not fertilised are normally:
1. There was not enough pollen around because plants were planted too far apart
2. The silky threads of the tassel were not sticking out of the top of the cob by the time the
pollen fell. This is mostly because the plant was not growing well enough.
A poorly pollinated corncob
Insects
Some of the insects that badly damage corn in other parts of Papua New Guinea do not
seem to be a problem in most parts of the Southern Highlands. This includes the European corn
borer and the corn earworm. Other armyworm caterpillars like the lawn armyworm only come in
plagues occasionally.
A black cutworm caterpillar
The cutworm moth
The black cutworm is the grey or green caterpillar of a moth. The moth is brown on the
front wings and yellow and brown on the hind wings. The caterpillars curl up and hide near the
base of the plants of just under the soil during the day. Then at night they come out and chew off
plants near ground level. One method of stopping them has already been mentioned.
Insect pests of corn
African armyworm
Cape gooseberry budworm
Corn earworm
Maize stem borer
Paddy armyworm
Rice armyworms
Rice leaf roller
Violet rice stem borer
Black flea beetle
False wireworm
Leaf beetles
Monolepta beetles
Pumpkin beetles
Shot hole weevils
Corn laternfly
Corn leaf aphid
Red cotton bug
Sugarcane aphid
White jassid
Fruit fly
Melon fruit fly
Shootfly
Adults feeding on cobs
Plant hopper
Damaging corn
Spodoptera exempta (Walker)
Heliothis assulta Gn.
Heliothis armigera (Huebner)
Ostrinia furnacalis (Guen.)
Spodoptera mauritia (Boisduval)
Mythimna loreyi (Dup.) &
Mythimna separata (Walk.)
Cnaphalocrocis medinalis (Gn.)
Sesamia inferens (Walker)
Arsipoda tenimberensis Jacoby
Gonocephalum ochthebioides Ful.
Cassena intermedia Jac. &
Cassena papuana (Jac.)
Monolepta spp.
Aulacophora spp.
Oribius spp.
Peregrinus maidis (Ashmead)
Rhopalosiphum maidis (Fitch.)
Dysdercus cingulatus (F.) &
Dysdercus sidae Montr.
Aphis sacchari Zehntner
Cicadella spectra (Dist.)
Dacus papuaensis Malloch
Dacus cucurbitae Coq
Atherigona orientalis Schiner
Chaetocnema basalis (Baly)
Coelophora ripponi Crotch
Compsolacon gracilis Candeze
Euricania discigutta (Walk.)
Hypolixus mastersi Pascoe
183
Noctuidae
Noctuidae
Noctuidae
Pyralidae
Noctuidae
Noctuidae
LEPIDOPTERA
LEPIDOPTERA
LEPIDOPTERA
LEPIDOPTERA
LEPIDOPTERA
COLEOPTERA
Pyralidae
Noctuidae
Chrysomelidae
Tenebrionidae
Chrysomelidae
LEPIDOPTERA
LEPIDOPTERA
COLEOPTERA
COLEOPTERA
COLEOPTERA
Chrysomelidae
Chrysomelidae
Curculionidae
Delphacidae
Aphididae
Pyrrhocoridae
COLEOPTERA
COLEOPTERA
COLEOPTERA
HEMIPTERA
HEMIPTERA
HEMIPTERA
Aphididae
Cicadellidae
Tephritidae
Tephritidae
Muscidae
Chrysomelidae
Coccinellidae
Elateridae
Ricaniidae
Curculionidae
HEMIPTERA
HEMIPTERA
DIPTERA
DIPTERA
DIPTERA
COLEOPTERA
HEMIPTERA
COLEOPTERA
HEMIPTERA
COLEOPTERA
Aphids
Borers
Mildew
Corn as a food
Most Papua New Guinea village people harvest corn from the gardens when it is in a
fairly firm mature stage and eat it the same day. It is mostly roasted over the fire.
The food value of corn varies with the type of corn and its stage of maturity. An
approximate value for corn as eaten in Papua New Guinea is below. It is the amount of different
nutrients in 100 gms of the part eaten.
Corn
Moisture
%
62.5
Energy
cals
134
Protein
g
4.2
Calcium
mg
5
Iron
mg
0.9
proVitA
!g
provitC
mg
Zinc
mg
This means that corn is a food high in energy and quite high in protein. Corn should be
included in the diet as often as possible because of this good food value.
Ginger
Tok pisin: Kawarare
Scientific name: Zingiber officinale
The plant
This plant has underground stems (rhizomes) that are branched and thickened. These stems
are yellow on the outside and about 2 cm thick. These have a distinct smell when cut or bruised.
The leaves are long and carried on a stem which is up to a metre high. The leaves clasp the stem
near the base.
Growing ginger
Ginger is popular in Papua New Guinea not just as a flavouring, but is eaten in quite large
quantities. It will grow well from sea level up to about 1900 metres altitude but is also grown at
high altitudes. In several areas it is regarded as a men's crop and is also used in magic and
medicine.
Ginger is grown by planting a piece of the underground stem. This is planted about 5 to 7
cm under the soil. It requires a good fertile soil and preferably good sunlight although some
varieties will grow quite well in light shade. During the early growth it needs adequate rainfall but
near maturity often ripens better with a drier season. The soil needs to be well drained so often
ginger is grown on raised beds.
As food
The underground stem is eaten. It can be eaten raw. The young shoots of the plant are spicy
and can be eaten.
185
Pests and diseases
Diseases of ginger
Leaf spot
Leaf spot
Leaf blotch
Root knot
Fungus
Fungus
Fungi
and
& Bacteria
Nematode
and
Pyricularia zingiberi
Phaeodactylium alpiniae
Curvularia sp.
Glomerella cingulata
Corynebacterium sp
Meloidogyne incognita
Meloidogyne javanica
Ginger insect pests
Leaf eating ladybird Henosepilachna signatipennis Boisd.
and
Henosepilachna haemorrhoea (Biel) Coccinellidae (COL)
Both the larvae and adults eat the leaves, young fruit and flowers of
plants. They eat ginger. They tend to eat the fleshy part of the leaf
underneath the leaf. They tend to prefer higher humidity. These ladybird
beetles have a covering of fine hairs which helps tell them from the good
species which feed on aphids.
Banana aphid Pentalonia nigronervosa Coq Aphididae HEMIPTERA
Bananas are the main plant attacked, but taro and ginger family
plants can also be attacked. Honey dew secreted by the insects cause sooty
moulds to grow. Ants also occur in association with these insects and they
help reduce the affect of predators.
Cardamom mirid Ragwelellus horvathi Poppius Miridae (HEM)
The adults and nymphs feed on leaves of cardamom leaving clear
empty cells between the veins. They also damage ginger. Damage can be
severe. The level of shade does not seem to affect the likelihood of damage.
Other minor pests
Dichocrosis sp.nr punctiferalis Guenee
Pyralidae (LEP.) Peach yellow moth
Reported damaging wild ginger. Occurs to 1750 m. Found incidentally on many plants. Caterpillar is red brown and
lives in a web made of frass. The pupa lies in a fairly solid cocoon.
Dindymus pyrochrous Boisd.
Pyrrhocoridae (HEM.)
Lema wauensis Gres.
Chrysomelidae (COL.)
Meijerella inaequalis Becker
Chloropidae (DIPT.)
Larvae in ginger. Syn. Oscinella inaequalis
Thressa punctifera de Meijere
Chloropidae (DIPT.)
Armoured scales and mealy bugs
Aspidiella hartii (Cockerell)
Pinnaspis strachani (Cooley)
Icerya seychellarum (Westwood) On wild ginger.
Ferrisia virgata (Cockerell)
Planococcus pacificus Cox
Wild ginger
Scientific name: Zingiber zerumbet
This species also occurs in Papua New Guinea. The leaves are slightly wider and more rounded
than ginger.
Job's tears
Tok Pisin: no name
Tok Ples names: Mendi - holo
Scientific name: Coix lachryma-jobi
The Job's tears plant
This is a grass that grows each year from seeds. It can be up to 2 metres tall. Near the
ground it has thick roots that hold the plant up. It produces large seeds that turn grey as they get
older.
Where it grows?
It grows wild in swampy places from sea level up to 2000 metres above sea level.
The seeds
In many places the seeds are used for making necklaces. In the Mendi Valley the seeds are
eaten regularly, by children. In some other countries the seeds are planted and the seeds used more
commonly for food. The seeds are hard but they can be crushed and the flour collected. This flour
cannot be used for bread unless it has other flour added because the bread won't rise.
The seeds store well, so they could also have some use as pig or poultry food.
187
Peanuts
Name: Peanut (Groundnut)
Tok Pisin: Pinat
Scientific name: Arachis hypogea
The plant
This is a spreading leafy plant that grows each year from seed. The plant is about 25 to 50
cm high and produces yellow flowers. The leaf has four leaflets. The stalk or peg from the flower
grows down into the soil and then produces the pod and seed under the ground. The flower needs
to be no more than 18 cm from the soil for the seedpod to develop under ground.
Two main kinds occur. They are often called runner and bunch types. The runner kind has
a vegetative or leafy branch between each fruiting branch and therefore produces a more spreading
type of plant. This is called "Virginia" peanut. These have a longer growing season and the seeds
need to be stored for a while before they will start to regrow. (30 days.) The pods have 2 dark
brown seeds. The other kind produces fruiting branches in a sequence one after the other along the
branches. These are called "Spanish-Valencia" types. They grow as a more upright plant and grow
more quickly. They have lighter coloured leaves and the pods have 2 to 6 seeds that are often
white.
Growing peanut
Peanuts grow well from sea level up to about 1650 metres altitude. It needs a temperature
of about 28°C and between 24°C and 33°C. The plants get killed by frost. They need a welldrained soil and cannot stand waterlogging. Therefore they are often grown on raised garden beds.
They do better in drier areas but need 300 to 500 mm of rain during the growing season. Near
harvest dry weather is needed.
Peanuts require soil with good levels of calcium or they produce empty pods. Many soils in
Papua New Guinea already have good levels of limestone. Adding gypsum will improve this. If
the nutrient boron is short then flowers won't flower and fruit properly. Because peanuts are
legumes, they have root nodule bacteria that can fix their own nitrogen and this means they can still
give good yields in grassland soils where nitrogen is at a lower level.
The seeds or nuts are normally removed from the shell before planting and are sown 2 to 3
cm deep. A suitable spacing is 10 cm between plants and 60 to 80 cm between rows. The soil
needs to be weeded and loose by the time the flowers are produced to allow the peg for the
seedpods to penetrate the soil. Normally when the whole plant dies off the plant is ready to pull.
They are left to dry in the sun for 3 or 4 days. It takes about 4 or 5 months from planting to
maturity.
Lamprosema indica
Achaea janata
Homona coffearia
189
Ectropis sabulosa
Pest and disease
Peanut insect pests
Bean leaf rollers
and
Cacao false looper
Cacao looper
Cluster caterpillar
Coffee leaf roller
Cowpea aphid
Grass bug
and
Horned weevil
Mole crickets
Pineapple mealy bug
Pumpkin beetles
Taro beetles
Leaf roller
Lamprosema indica F.
Lamprosema diemenalis (Guenee)
Achaea janata (Linnaeus)
Ectropis sabulosa Warr.
Spodoptera litura (Fab)
Homona coffearia Nietn.
Aphis craccivora Koch
Alticus tibialis Reut
Alticus minutus Reut
Apirocalus spp.
Gryllotalpa africana Pal.
Dysmicoccus brevipes (Cockerell)
Aulacophora spp.
Papuana spp.
Adoxophyes melichron
Euborellia annulipes Lucas
Megalurothrips usitatus Bagnall
Nysius epiensis China
Orosius argentatus Evans
Oxidus gacilis
Philia femorata Walk.
Coccus longulus (Douglas)
Planococcus pacificus Cox
Pyralidae (LEP)
Pyralidae (LEP)
Noctuidae (LEP)
Geometridae (LEP)
Noctuidae (LEP)
Tortricidae (LEP)
Aphididae (HEM)
Miridae (HEM)
Miridae (HEM)
Curculionidae (COL)
Gryllotalpidae (ORTH)
Pseudococcidae (HEM)
Chrysomelidae (COL)
Scarabaeidae (COL)
Tortricidae (LEP.)
Labiduridae (DERM.)
Thripidae (THYS.)
Lygaeidae (HEM.)
Cicadellidae (HEM.)
Pentatomidae (HEM.)
Coccidae (HEM)
Pseudococcidae (HEM)
Diseases
Leaf loss due to leaf spot and rust can be considerable during the wet season. Plants
maturing as the dry season starts get less leaf spot damage. The Spanish sequential branching
types of peanuts get more damage from leaf spot.
Seedling death and collar rot can become important in damp soils.
Rust
Peanut diseases
Seedling death
Collar rot
Large leaf spot
Leaf spot
Leaf spot
Leaf spot and pod rot
Leaf spot
Collar rot
Rust
Root rot
Blackening stems
Bacterial wilt peanut
Mosaic
Leaf mottle
Mild mottle
Aspergillus niger
Athelia rolfsii
Botryodiplodia theobromae
Leptosphaerulina trifolii
Cercosporidium personatum
Colletotrichum sp.
Leptosphaerulina trifolii
Mycosphaerella arachidicola
Mycosphaerella berkeleyi
Phomopsis sp.
Puccinia arachidis
Pythium sp.
Rhizoctonia
Thanatephorus cucumeris
Pseudomonas solanacearum
Fungus
Fungus
and
Fungus
Fungus
Fungus
Fungus
Fungi
and
Fungus
Fungus
Fungus
and
Fungus
Bacterium
Virus
Virus
Virus
Marginal leaf chlorosis virus
Cowpea mild mottle virus
Bacterial wilt of peanut is caused by a bacteria Pseudomonas solanacearum. Plants wilt and when the stems are
cut there is a brown discolouration of the tissues. Temperatures between 25° and 35°C suit the disease best. The
bacteria can spread in soil or by water running down hill from an infected area. It affects plants by blocking the
conducting cells that allow food and water to pass up and down the plant. Plants wilt and die. This bacterium affects
many different plants including tomato, potato. Control is by avoiding infected soils. Don't plant crops that can be
damaged downhill from infected crops. For most crops resistant varieties have been developed. For further
information see Plant pathology Note No.15 of Harvest 7(4) p180 and Tomlinson, D. L., Mogistein, M., 1989,
Occurrence of bacterial wilt of peanut (Arachis hypogea ) caused by Pseudomonas solanacearum and opportunistic
infection of aibika (Abelmoschus manihot ) in Papua New Guinea. Plant Pathology 38(2), 287-289.
Collar rot of peanuts is also called Aspergillus crown rot peanuts and is caused by a fungus Aspergillus niger.
(Athelia rolfsii fungus can also cause collar rot of peanuts.) If seeds are dug up they are covered with a sooty looking
mass of black spores. The young seedlings can fall over and die due to the stem rotting off near the ground. The lower
leaves of the plant become yellow. All stages from planted seeds to mature plants can be attacked. The fungus can live
in dry soils and the disease likes high temperatures (30°C to 35°C). The fungus lives in the soil and on rotting plant
materials. Seeds can also be infected and often carry the disease. The fungus is common in soil. It gets most serious
where peanuts are grown in the same area for several crops. Plants can die. For control don't plant seed too deeply; use
good quality undamaged seeds and chemical seed dressings can be used (But they are dangerous). Crop rotation or
moving garden sites is important. Remove old plant rubbish (not only peanut plants). Be careful not to damage
growing plants.
Peanut leaf spot has two similar fungi involved Mycosphaerella arachidis and Mycosphaerella berkeleyi of which
the asexual stages are Cercospora arachidicola and Cercosporidium personatum. Small brown pale areas develop on
the older leaves of peanuts. These spots become dark brown (with C. arachidicola) and black (with C. personatum).
The disease is worse with temperatures between 20°C and 30°C and high humidity. Heavy rain helps the fungus
spread. Poor soil fertility can increase the damage. The disease can live on old plants and peanut rubbish. Leaves can
fall off early and less peanuts are then harvested. For control remove old peanut plants and plant peanuts in different
areas each time. Use wider spacing between plants. Chemical fungicides can be used.
Peanut marginal chlorosis is caused by peanut marginal leaf chlorosis virus. Two or three weeks after sowing
the leaves of diseased plants turn yellow on the edges. They also become wrinkled. The plants are smaller than normal.
The virus spreads in the seeds. No insects appear to be involved. The disease can be transmitted by grafting and could
possibly be transmitted by plants rubbing together. The plant produces less nuts than normal. (About half). Control is
by using seed from healthy plants.
Peanut mild mottle is caused by cowpea mild mottle virus. Small pale indistinct spots develop on the leaf surface.
Veins on the leaf can go pale of clear. The leaves can turn yellow, go brown or bronze underneath or the leaves die.
Leaves can also roll upwards. This disease can be spread by being in the seed before they are planted or it can be
spread between plants by a small sap sucking insect called the tobacco whitefly. So far the disease is only of minor
191
importance. This virus disease can occur on many different bean family plants. For control it is necessary to pull out
and burn diseased plants. Other bean family plants should be checked and either removed if diseased of kept at a
distance from peanut plants. Do not use seed from infected plants. Whitefly can be controlled by insecticides. Further
information can be found in Philemon, E. C., Harvest 12(4) p 15 or Plant Pathology Note No 32.
Peanut rust is caused by a fungus Puccinia arachidis. Orange red lumps occur on both top and bottom side of
peanut leaves. It gets worse in the wet seasons. It is mostly spread by wind and rain. Leaves and plants can die. It gets
worse as plants get near maturity. Some varieties get less disease so should be used. Other information can be found in
CMI Descriptions of Pathogenic Fungi No 53 and Map 160 and Pest Control in Groundnuts. PANS Manual No 2 p 27.
Pepper spot & scorch of peanuts is caused by a fungus Leptosphaerulina trifolii. Very small spots (less than 1
mm) develop on the upper side of the leaf. Spots can join together and cause leaves to die. If the disease is near the
edge of the leaf it can be brown with a yellow margin and is called scorch. It gets worse with warm wet weather. The
disease is spread by wind. It can be controlled with fungicide chemicals.
Stem rot of peanuts is also called Sclerotium crown rot and is caused by a fungus Athelia rolfsii of which the
asexual stage is Sclerotium rolfsii. White fungal threads can be seen over brown diseased areas of the stem near ground
level. Small hard round bodies (called sclerotia) are produced near the soil. The disease spreads more rapidly under
high humidity and wet soil. It can still grow with soil pH from 1.4-8.8. It can live for many years in the soil. The
fungus can live in the soil for several years. The fungus spreads in moist weather and can grown over the surface of the
soil. It mainly spreads on plant remains but can also spread on seed and on tools. Whole plants or single runners can
die. Pegs carrying the peanuts may rot off so that the nuts stay in the ground. Other plants that get the disease include
cabbage, beans, capsicum, giant taro, artichoke, lettuce, naranjilla, pawpaw, peanut, peas, pomelo, potato, rice, corn,
sugarcane, sunflower, sweet potato, tomato and pepper. For control improve the drainage and grow the crop well with
good weeding, careful digging etc. Use resistant varieties. Runner types of peanuts get less damage. Use good crop
rotations. The disease gets worse where leaf spot has been bad. Harvest the crop as soon as it is ready.
Peanuts that are not quickly and properly dried can develop fungal attack and a disease
called aflatoxin that makes them poisonous.
As food
Mostly the seeds are eaten raw. Occasionally the seeds are roasted or processed then eaten.
The leaves are occasionally cooked and eaten.
Pitpits
Coastal pitpit
or long pitpit
Saccharum edule
Highlands pitpit
Or short pitpit
Setaria palmifolia
193
Coastal pitpit
Tok Pisin: Pitpit
Scientific name: Saccharum edule
The pitpit plant
The pitpit plant looks like sugarcane to which it is related. Normally the stalk is thinner
than sugarcane.
It can grow up to 3 metres high and produces suckers near the base so that normally a clump
is produced.
At one season of the year it produces a seed head or flower that remains inside the top of the
plant and is the part that is eaten.
Pitpits
In Papua New Guinea in Tok Pisin, several tall grass plants are called pitpit. Two of these
are grown in gardens to be eaten as food. One of them is like sugarcane, it tends to grow at lower
altitudes and it is therefore often called coastal pitpit or lowland pitpit. It is also sometimes called
long pitpit because it is a taller plant. Its scientific name is Saccharum edule and this means the
sugarcane grass that can be eaten. It was given this name by a man called Hasskarl in the year
1842. This is the pitpit that this article is about.
The other pitpit that is grown for food is often called highland pitpit or short pitpit because
it is a shorter plant and it grows better up in the highlands. Its scientific name is Setaria palmifolia
and it is described in a separate article.
Occasionally the young shoots are eaten of the pitpit that is used for fences.
Where is coastal pitpit grown?
Coastal pitpit is grown throughout Papua New Guinea from the sea level up to about 1700
metres altitude.
It is also grown in some other countries. It is grown in the Solomon Islands, Vanuatu, and
Fiji and also in Indonesia.
How do you grow pitpit?
Pitpit is grown by taking cuttings of the cane, and sticking them in the ground. Mostly
cuttings about 30-50 cm long are used and they need to be planted in a moist soil. They easily dry
out so need to be planted soon after cutting. These cuttings soon develop roots and produce a
number of shoots so that a clump of canes grows.
Coastal pitpit stalks can be planted at any time of the year. It takes 6-9 months from
planting till a crop is ready to harvest. But the time of flowering in coastal pitpit is controlled by
the sun. Early in the year about February to March most plants develop a thickened clump of leaves
at the top. When these are broken off and opened by removing the outside leaves the very fine
yellow unopened flower is seen. It is this flower that is eaten
An easy way some people plant coastal pitpit is to cut a long pitpit stalk. Then at the places
where they want to plant it in the garden they stick the stalk into the ground and chop off the longer
top piece with a bush knife. They cut it so that about 15 cm is under the ground and 15 cm left
sticking out of the ground. The longer piece is then stuck in the ground in another place and cut off
again.
If the pitpit flower is not picked when it is ready it starts to go brown due to a fungal rot.
In places where the soil is very fertile the canes can be cut off after harvest and new shoots
will sucker out around the base and grow to produce another clump.
195
Pest problems
Coastal pitpit is attacked by some insect and disease problems. For these see under the
sugarcane section.
The most common and most important insect pest of coastal pitpit are borers boring into the
canes. These are normally the larvae of the same moths that bore into sugarcane. Several different
moths cause this damage because there are different moths in different places throughout the
country. In the Southern Highlands it mostly seems to be a small white grub with black spots along
its back. Its scientific name is Chilo terrenellus. If it eats its way up the stalk till it damages the
growing point it can kill the stalk.
A number of different fungal leaf spots can be seen growing on the leaves of pitpit. They
are mostly the same as the fungal diseases that grow on sugarcane. It is not known how important
they are to growing good pitpit.
Coastal pitpit as food
In 100 grams of the part you eat there are the following amounts of nutrients.
Moisture
%
92.4
Energy
cals
25-38
Protein
g
4.1-4.6
Calcium
mg
10-40
Iron
mg
2
proVitA
!g
0
provitC
mg
21-50
Zinc
mg
This means that coastal pitpit is only moderately good at providing energy but it is quite
high in protein. It is therefore especially good as a body building food and can make an important
contribution to the diet.
Young coastal pitpit flowers can be eaten raw. But they are fairly dry. In coastal areas one
of the favourite ways to eat this pitpit is fried in grated coconut milk. The pitpit can be baked in its
leaves over an open fire. Or it can be boiled or fried along with other greens.
Highland pitpit
Tok Pisin name: Pitpit
Scientific name: Setaria palmifolia
The highland pitpit plant
This is a short, broad -eafed grass family plant. The leaves have ridges running along their
length. They also normally have a wrinkled section near the middle of the leaf. The leaf blade is
short (30-40 cm) and fat (6-8 cm) and the leaves spread out along opposite sides of the shoots.
Normally a plant produces a clump of shoots due to both suckers near the base and buds
growing from the side of the short stem.
A plant grows from 60 cm to one metre tall.
Several different kinds of highland pitpit occur. These have different amounts of red, green
and white colouring on the leaf and also where the leaves wrap around the stem.
It is the young tender tightly wrapped leaves inside the thickened base of the shoot that is
eaten.
The wild relative from which the garden pitpit has been produced can often be seen growing
in grassland around garden areas. It is a thinner plant often produces a flower and the young shoots
are also eaten.
197
Where is highland pitpit grown?
Highland pitpit is common and an important food plant in many areas of Papua New
Guinea.
It tends to be more important in the highlands. It grows and produces reasonably well
between the altitudes of 400 and 2400 metres above sea level. It can be grown down to the coast.
But Papua New Guinea is not the only country that grows this plant as food. It is grown in
Fiji, Hawaii, Tonga and some other Pacific countries.
How do you grow pitpit?
It is grown by planting young shoots.
A young shoot of the
type that is planted.
The young shoots are broken off the side of the plant. Shoots near the ground often have
roots already growing on them so these shoots start growing more quickly. Portions of the stem can
be planted because buds near the joints along the stem can produce new shoots.
This pitpit needs reasonably fertile soil and won't grow or produce well in old kaukau
gardens. A leaf of a plant growing in good fertile soil is dark green.
A normal, dark green pitpit leaf.
Why are some pitpit leaves dry?
It is necessary to learn to tell the difference between a plant that is running out of nutrients
(gris) and a mark due to a disease.
One of the commonest "dry" marks on pitpit is a leaf tip going dry and brown from the tip
down. The dry mark extends in a V shape down the centre of the leaf. This is most likely nitrogen
deficiency. It mostly occurs on older leaves and in older gardens.
A leaf going dry due
to nitrogen deficiency
Sometimes leaves go dry along the edge. This is possibly potash deficiency.
Disease leaf spots can often be seen on pitpit leaves. The cause is most likely a fungus. The
importance of these has not been measured. There appear to be two different types of leaf spots
probably due to two different fungi.
The larger disease leaf spots
look like this
Other fungal diseases also occur. Small black spots called "tar spots" can sometimes be
seen on leaves. They are like small specks of tar that have been dropped on the leaf. They are due
to another fungus but they don't appear to be important.
"Tar spots" on pitpit leaves
199
Two "rust" fungi have also been recorded on pitpit leaves.
Insects damaging pitpit
Borers get into pitpit and kill the shoots. These borers are mostly the larvae of the moths
that bore into sugarcane and coastal pitpit. The amount of damage varies but it can sometimes be
serious. A shoot of a plant that has been damaged by a borer goes dry and the shoot or whole plant
can die.
Pests and disease of Highland pitpit
Damage
Tar spot
Rust
and
Leaf spots
Borers
Cause
Scientific name
Fungus
Fungus
Fungus
Fungus
Insect
Phyllachora sp.
Uredo palmifoliae Cummins
Uromyces leptodermus Sydow
Probably fungi
Chilo sp.
Wild highlands pitpit
In most areas in the highlands the wild relative from which the garden pitpit has been
produced can be seen growing. Often it occurs along tracks and roadsides near creeks and in old
garden sites. Most Southern Highlands people have a different name for this plant in their local
languages. But they know it is the wild plant from which the better, fatter garden plant was
produced.
The shoots of this plant are also eaten although they are mostly eaten raw by hunting parties
and people walking through the area.
The plant also gets similar diseases to the garden variety.
Harvesting and use of pitpit
The young end and side shoots are harvested from pitpit plants. Sometimes these are tied in
a bundle and sold in markets.
The amount of the shoots that is eaten varies. The tough outside leaves are stripped off.
These are normally fed to pigs.
Then the younger more tender inside of the shoot is eaten.
A shoot stripped for eating
At least in some of the higher places in the Highland Provinces these young shoots are often
eaten raw. But they can also be mumued in an earth oven or steamed in bamboo, or boiled or fried
in a saucepan. Often they are eaten with a kumu called Rungia.
How much food is produced?
In trials between 8 and 18 kilograms of shoots have been harvested from individual plants
over one year. These plants were spaced one metre apart. But only a third or less of these shoots
were actually eaten as the outside portion was fed to pigs and the tender inside shoot eaten.
So a garden plot of pitpit of 10 square metres may produce between 25 and 60 kilograms of
edible shoots.
Pitpit is often grown mixed with other crops in the food garden. It is also commonly grown
in partly shaded places such as under yar trees. How much it produces in these situations is not
known.
The food value of pitpit shoots
In a 100 gram portion of the shoots that are eaten there are the following amounts of
different nutrients.
Moisture
%
23-27
Energy
cals
Protein
g
0.5-2.3
Calcium
mg
7-21
Iron
mg
0.9-2
proVitA
!g
500
provitC
mg
12-33
Zinc
mg
(A 100 g edible portion is about 5 large stripped shoots.)
This means that pitpit shoots are not very good as a means of getting energy and the protein
content is probably higher than root crops like kaukau but not as good as most dark green leaves.
Nevertheless they are an enjoyable and reasonably nutritious food.
201
Pumpkin family plants
There are quite a few plants in the pumpkin family that are used as food in different areas of
Papua New Guinea. Often it is the leaves and seeds that are used as well as the fruit.
The scientific and common names of those that are known to be used as food, are listed in
the table below.
Angled loofah
Bitter cucumber
Bottle gourd
Choko
Cucumber
Kongkonga
Marrow
Melon
Pumpkin
Pumpkin
Smooth loofah
Snake gourd
Watermelon
Wax gourd
Luffa acutangula
Mormordica charantia
Lagenaria siceraria
Sechium edule
Cucumis sativa
Diplocyclos palmatus
Cucurbita pepo
Cucumis melo
Cucurbita maxima
Cucurbita moschata
Luffa cylindrica
Trichosanthes cucumerina
Trichosanthes pulleana
Citrullus lanatus
Benincasa hispida
What do they all look like?
Angled loofah
Choko
Bitter cucumber
Bottle gourd
Cucumber
Melon
Kongakonga
Marrow
Cucurbita maxima
Pumpkin
Cucurbita moschata
Snake gourd
Melon
Smooth loofah
Wax gourd
Tricosanthes pulleana
203
Which parts are eaten?
Wax gourd
Kongakonga
Watermelon
Melon
Cucumber
Pumpkin
Native pumpkin
Marrow
Bottle gourd
Angled loofah
Smooth loofah
Bitter cucumber
Choko
Snake gourd
Tricosanthes
Fruit
"
"
"
"
"
"
"
"
"
"
"
"
"
Leaves
"
"
!
!
"
"
"
"
"
"
"
!
"
"
Seeds
"
Flowers
"
Roots
"
"
"
"
"
"
"
"
"
"
"
Where are they grown?
Altitude
Lowlands
Rainfall
Medium dry areas
Lowlands
Hot dry areas
Melons
Cucumbers
Pumpkin
Native pumpkin
Marrow
Bottle gourd
Lowlands
All areas
Drier areas
Lowlands
Dry areas
Angled loofah
Smooth loofah
Bitter cucumber
Choko
Snake gourd
Tricosanthes pulleana
Lowlands
Lowlands
Lowlands
Mid altitude
Lowlands
Highlands
Wax gourd
Kongakonga
Watermelon
Wetter areas
All areas
Moderate rainfall
Comments
Only occasionally in Rabaul market
Mainly used at Rabaul
Common in all coastal areas especially dry sandy
areas
not common
Very common in all highland areas
More common in highlands
Common for leaves
Not common
As food only eaten in some highland areas eg
Upper Mendi
Occasional in several lowland areas
Occasional in lowland areas
Occasional in several coastal areas
Very common in mid altitude areas
Occasional mainly in Sepik
Occasional in many areas
Bottle gourd
Tok Pisin: Botel
Scientific name: Lagenaria siceraria
Tok Ples names:
Mendi - pe hipap
The Bottle gourd plant
This plant is in the pumpkin family. It can climb over logs by attaching the tendrils that
grow out of the stem near the leaf. The leaves are large and have soft hairs especially underneath.
The plant produces male flowers first and these are on long stalks. These don't produce
fruit. Further along the stalk female flowers on short stalks are produced. If these are pollinated by
pollen carried by insects from the male flowers then fruit will be produced.
The seeds are brown and in the light green pulp of the fruit. The shape of the fruit varies.
Where are bottle gourds grown?
Bottle gourds have been grown for thousands of years in Africa, South America and are
also grown in India, China and many Asian and Pacific countries.
They are also grown in many areas of Papua New Guinea.
In the Southern Highlands Province they are common in some areas such as the Upper
Mendi Valley, but are grown sometimes in most places.
How does a bottle gourd grow?
It grows quickly and may start to flower 2 months after sowing the seeds.
When fruit start to develop the vine mostly stops growing. If the fruits are removed
growth of the vine continues.
Young fruits can be ready for harvesting about 3 months after planting.
Young fruits when harvested will only keep for a very short time of about 1-2 weeks.
205
Diseases
Bottle gourd leaves can get a white powdery type of growth over the leaves. This is due to
a powdery mildew fungus. Sometimes as well the leaves and plant can die off early with leaves
turning brown. This is called anthracnose. Both these diseases are less if plants are well staked up
so that leaves dry quickly after rain. Also some kinds of bottle gourd get less damage.
Diseases
Powdery mildew
Anthracnose
Fungal cause
Oidium sp.
Glomerella cingulata
How do you grow bottle gourds?
The seeds are light brown colour and look like this.
They need to be spaced about 1 metre apart.
They need to be in a sunny position so should not be put under yar trees or in shady
places.
Preferably they should be allowed to climb over a trellis or logs so that the wind can dry
the leaves quickly after rain.
The soils need to be fairly fertile because bottle gourds grow rapidly. Therefore they
should be in newer gardens or in soil where the fertility has been built up.
They are killed by frost.
How to use bottle gourds, and their food value?
Normally the young bottle gourd fruits are eaten as a boiled vegetable.
Sometimes the seeds are used in soups.
The young leaves are also eaten in some places.
Some kinds of bottle gourds can have a bitter taste.
The bottle gourd is a nice addition to the diet but it has little food value. The amounts of
different food nutrients in 100 g portion of the part that is eaten are:
Fruit
Moisture
%
96.1
Energy
cals
12
Protein
g
0.2
Calcium
mg
20
Iron
mg
0.7
proVitA proVitC
!g
mg
0
6
Zinc
mg
The mature fruit are dried and cleaned and used as containers. They make very good
bottles and containers for seeds and other things.
Choko
Tok pisin: Sioko
Scientific name: Sechium edule
Tok Ples names:
Foi - soga sai
The choko plant
The choko plant belongs to the pumpkin family. The vine on which the leaves and fruit are
produced can grow quite long. It can be up to 15 m long. As well it has strong tendrils that can
attach to fences and trees so that the plant can climb well.
The choko leaves are about 15-20 cm across and have a rough feel.
The choko fruit is produced in the angle where the leaf joins the vines. Fruit can be up to 20
cm long and they are rough or irregular shaped on the outside. There are white and green-fruited
varieties. Some fruit have sharp spikes on the skin. Inside the fruit there is one seed about 4 cm
long.
A choko attached to a post
207
A choko plant produces a large thickened root tuber and the plant can regrow from this
tuber and go on growing year after year.
The importance of chokos
Although choko is a plant that was introduced to the Highlands Provinces only in recent
years it has become very popular and widely used in some areas.
Chokos will grow from sea level up to at least 2200 m altitude. But at altitudes of about
800 to 1200 metres they grow particularly well and very easily. Therefore people like the Foi near
Lake Kutubu, the Pole at Erave and the Podopa near Woposali have adopted choko tips as one of
their main edible greens. In most of these areas the soft fleshy fruit are not particularly popular and
are only eaten occasionally. Also the large underground tuber that is edible, has been tried by many
people in these areas but it is not liked very much. The underground tuber is something like a yam
but is softer and it is not eaten often.
A choko fruit
Planting chokos
The choko fruit has one large seed inside. But the seeds cannot be dried out at all or it won't
grow. Therefore the whole fruit is planted.
A choko fruit cut
in half showing
the seed inside
A choko fruit growing
roots and shoots
Often chokos start to develop shoots and roots while they are still attached to the original
plant. These eventually fall off and continue growing if they fall on soft moist dirt.
If the fruit is planted it is planted on its side and only lightly covered with soil.
Choko plants can be grown from cuttings of the vine.
In areas where chokos are important they often just keep growing from the original plants or
from fruit that falls naturally. Therefore near Erave and Kutubu large choko gardens can be seen
where people mainly only ever go to harvest and rarely replant.
Chokos need some support to climb over. This is normally most cheaply and easily done by
planting it near a fence, tree or logs.
Production
Chokos need a reasonably well-drained soil. But they can be grown under shade. In the
lower altitude hotter places it seems as if shade is important for growing good chokos.
Plants take about 4 months from planting until fruit are produced.
Fruit can weigh 400 to 500 grams.
Tubers of 5 kg weight have been recorded.
Chokos as food
Normally the leaf tips, the underground tuber and the fruit are all cooked before eating.
Sometimes the young seeds are eaten.
In 100 grams of the part that is eaten chokos have the following amounts of nutrients.
Moisture Energy Protein Calcium
Iron
proVitA provitC
Zinc
%
cals
g
mg
mg
!g
mg
mg
Fruit
89-92
6-8
0.8-0.9
10
0.4
650
20
Leaves
89
25
4
60
1.4
25
Roots
79
17-23
2
This means that the leaves are good food, the tuber is quite good and the fruit are poor for
providing nutrients for people.
209
Cucumber
Name: English: Cucumber
Tok Pisin: Kukamba
Scientific name: Cucumis sativus
People in the highlands of Papua New Guinea, claim that they have always had cucumbers.
They maintain that they are one of their traditional foods. They have local names in Tok Ples
languages. They are common and popular in most highland regions.
They are grown from sea level up to about 2200 m altitude.
Cucumbers are grown from seed and they are easy to grow. Mostly they are planted in new
gardens when people have cleared and established a new garden. In many areas this is early in the
new year. So often cucumbers occur in large numbers.
Two or three seeds are sown with a spacing of about 1 metre square per plant but often they
are intercropped with other plants. They are ready to harvest in about 6-8 weeks and produce about
10 fruit per plant.
People mostly eat them fresh for a snack in the garden.
Cucumbers suffer badly from mildew fungus on the leaves. Normally this means there are
not enough tops for the young leaves to be eaten.
Pumpkin
Two main kinds of pumpkin are grown in Papua New Guinea. The easiest way to tell the
difference between these species is by the way the stalk joins to the fruit. With Cucurbita moschata
the stalk becomes larger and is ridged near where it is attached to the fruit. The other one is
Cucurbita maxima. There are many different varieties of both these pumpkins.
Cucurbita moschata
Cucurbita maxima
The one, Cucurbita moschata, is often called the native pumpkin because it is more suited to
the lowlands and to warmer climates.
Pumpkins are easily damaged by mildew fungi and also by fruit flies especially in the
lowlands. Normally if seed is saved from local varieties of pumpkins it gets less mildew damage
than from imported seeds.
211
Fluted gourd
Name:
Scientific name: Luffa acutangula
This plant grows in lowland areas and is a large vigorous climber with square stems.
Normally plants are allowed to climb over a fence. It has yellow flowers that open at night. Most
flowers are male. The fruit can be up to 40cm long and with about 10 large ridges along their
length. The fruits are green when young and turn to brown when ripe. On the inside the flesh is
white.
It is grown from seed and fruit are ready about 6 to 10 weeks after planting. The immature
fruit are cooked and eaten.
Smooth loofah
Name:
Scientific name: Luffa cylindrica
The smooth loofah is grown in a number of coastal areas. The stem is five angled and
slightly hairy. The fruit is long (30 cm) and smooth. The young fruit are soft, but as they get old
they develop a thin hard skin that peels off. The fruit often have streaks along them. The young
fruit are cooked and eaten.
213
Bitter cucumber
This pumpkin family plant has fruit that are lumpy in appearance and are green but turn
yellow when fully ripe. Inside there are seeds in a bright red flesh. The vine on which it grows is
slender, grooved, long and with many branches. It has coiled tendrils opposite the leaves with
which it can attach to a fence or logs. The leaves are deeply divided and sometimes notched or
toothed.
It is grown from seed. Seeds have a hard coat and often germinate slowly. Then plant
grows very quickly and can be producing fruit in 2 months.
The fruit is somewhat bitter and is less bitter when fruits are younger. The seeds should not
be eaten. The flesh around the seeds is eaten, cooked or used to add flavour to other food.
Wax gourd
Name: Wax gourd
Scientific name: Benincasa hispida
This is a very large fruit that is oval or like a ball in shape. They can be 35cm high x 20cm
wide and they are green but covered with a white wax that is easily removed. Inside the flesh is
white and the seeds are in a spongy section in the middle. The seeds are flat smooth and pale.
In the Rabaul area this gourd is often grown for sale to Chinese people. It brings a very
good price.
The plants are grown from seed and are ready for harvest in about 4-5 months. They are
better suited to coastal areas where there is a seasonal dry period. Preferably they should be
allowed to climb over a strong trellis, or fence.
The fruit can be eaten cooked. The seeds can also be fried and eaten. The young leaves and
flower buds can also be cooked and eaten. The fruit keeps well.
215
Pumpkin family insect pests
Leaf chewing insects
Achaea janata (Linnaeus)
Chrysodeixis eriosoma Doubleday
Epilachna cucurbitae Richards
Henosepilachna spp.
Oribius spp.
Rhyparidella wauensis
Tiracola plagiata Walk
Psylliodes sp nr fulvipes Jacoby
Sap sucking insects
Altica sp
Alticus tibialis Reut
Aphis gossypii Glover
Aphthona bicolorata Jacoby
Aphthona sp nr scutellata Baly
Atherigona orientalis Schiner
Aulacophora spp.
Criocerus clarkii Baly
Bactrocera cucurbitae Coq
Bactrocera decipiens Drew
Bactrocera strigifinis atritus May
Dysmiccocus brevipes (Cockerell)
Ferrisia virgata (Cockerell)
Leptoglossus australis (Fab.)
Leptothea ciskii Weise
Macrosiphum euphorbiae (Thomas)
Mictis profana F.
Monolepta spp.
Paradacus perplexus
Pinnaspis strachani (Cooley)
Planococcus citri (Risso)
Planococcus pacificus Cox
Noctuidae (LEP)
Noctuidae (LEP)
Coccinellidae (COL)
Coccinellidae (COL)
Curculionidae (COL)
Chrysomelidae (COL)
Noctuidae (LEP)
Chrysomelidae (COL)
Cacao false looper
Green looper
Leaf eating ladybird.
Leaf eating ladybird
Shot hole weevils
Adults eating leaves of pumpkin
Cacao armyworm
Feeding on pumpkin leaves
Chrysomelidae (COL)
Chrysomelidae (COL)
Aphididae (HEM)
Chrysomelidae (COL)
Chrysomelidae (COL)
Muscidae (DIPT)
Chrysomelidae (COL)
Crioceridae (COL)
Tephritidae (DIPT)
Tephritidae (DIPT)
Tephritidae (DIPT)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Coreidae (HEM)
Coccinellidae (COL)
Aphididae (HEM)
Coreidae (HEM)
Chrysomelidae (COL)
Trypetidae (DIPT)
Diaspididae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Damage to pumpkin leaves
Grass bug
Melon aphid
Eating epidermis
Damage to pumpkin leaves
Shootfly
Pumpkin beetles
Feeding on leaves of pumpkin
Melon fruit fly
Fruit fly only on New Britain
Fruit fly on fruit and flowers
Pineapple mealybug
Black leaf-footed bug
Reported on pumpkins.
Potato aphid
Crusader bug
Monolepta beetles
In New Britain damaging pumpkin fruit
In some of the coastal areas, fruit fly damage to pumpkin fruit can be very serious. Aphids
can be important for spreading viruses. Pumpkin beetles are yellow and about 7mm long and are
very common. They can stop fruit forming by damaging flowers as well as eating leaves and
burrowing into stems.
Pumpkin beetle
Grass bug
Melon fruitfly
Green looper
Melon aphid
Pineapple mealybug
Leaf eating ladybird
Cacao armyworm
Psylliodes
Aphthona
Shootfly
Criocerus
Leptothea
Crusader bug
Monolepta beetle
Diseases pumpkin family
Bitter cucumber
Leaf spot
Powdery mildew
Downy mildew
Root knot
Bottle gourd
Powdery mildew
Anthracnose
Choko
Leaf spot
Leaf blotch
Soft rot
Cucumber
Leaf spot
Leaf spot
With fruit rot
Powdery mildew
Downy mildew
Leaf spot
Damping off
Fruit rot
Root knot
Storage rot
Melon (Rockmelon)
Black rot
Powdery mildew
Downy mildew
Root knot
Pumpkin
Storage rot
Sooty mould
Powdery mildew
Downy mildew
With storage rot
Mosaic
Rockmelon (See Melon)
Snake gourd
With leaf spot
Leaf spot
Squash and marrow
With storage rot
Leaf spot
Storage rot
Powdery mildew
Downy mildew
Mould under leaf
Possible virus
Watermelon
Leaf spot
Leaf spot
Black rot
Powdery mildew
Damping off
Mosaic
Fungus
Fungus
Fungus
Nematode
and
Cercospora citrullina
Oidium sp
Pseudoperonospora cubensis
Meloidogyne incognita
Meloidogyne javanica
Fungus
Fungus
Colletotrichum lagenarium
Fungus
Ascochyta sp.
Bacteria
Erwinia carotovora
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungi
and
Bacteria
Nematode
Fungus
and
and
and
Alternaria alternata
Corynespora cassiicola
Choanephora cucurbitarum
Oidium sp.
Pseudoperonospora cubensis
Phyllosticta sp.
Pythium butleri
Pythium deliense
Erwinia carotovora
Meloidogyne incognita
Colletotrichum sp.
Fusarium sp.
Phoma exigua
Pythium sp.
Fungus
Fungus
Fungus
Nematode
Mycosphaerella melonis
Oidium sp.
Pseudoperonospora cubensis
Meloidogyne incognita
Fungus
Fungus
Fungus
Fungus
Fungus
Virus
Colletotrichum lagenarium
Epicoccum sp.
Erysiphe cichoracearum
Pseudoperonospora cubensis
Rhizoctonia sp.
Melon mosaic virus
Fungus
Possibly bacterial
Colletotrichum orbiculare
Fungus
Fungus
Fungus
and
Fungus
Fungus
Fungus
Aspergillus sp.
Cercospora sp.
Colletotrichum lagenarium
Fusarium sp.
Oidium sp
Pseudoperonospora cubensis
Cercospora citrullina
Fungus
Fungus
and
Fungus
Fungus
Fungus
Probably virus
Cercospora citrullina
Colletotrichum lagenarium
Leptosphaerulina trifolii
Mycosphaerella melonis
Oidium sp.
Pythium irregulare
217
Root knot
Zucchini
Leaf spot
Fruit rot
Powdery mildew
Storage rot
Downy mildew
Nematode
Meloidogyne incognita
Fungus
Fungus
Fungus
Fungus
Fungus
Alternaria cucumerina
Choanephora sp.
Erysiphe cichoracearum
Fusarium sp.
Pseudoperonospora cubensis
The downy mildews can be serious with most of the pumpkin family plants especially in the
wet season. Some varieties of pumpkin family plants get serious damage. Having plants climb
over logs or other frameworks so that they are exposed to the sun and off the ground help control
the disease by letting the leaves dry quickly.
Powdery mildews tend to be more of a problem in the highlands. A fine layer of spores give
a powdery appearance to the surface of the leaves.
Often the kinds of pumpkin plants that have been grown for years have more resistance to
these diseases than the ones grown from seeds bought from stores. Using good crop rotations and
planting pumpkin family plants in new gardens away from old plants is important for control of
diseases.
Cucumber mosaic virus
Downy mildew (Cucumber)
Leaf spot (Watermelon)
Onions
Several plants in the onion family are grown occasionally in Papua New Guinea. These include:
Bulb onions
Shallots
Leek
Garlic
Chives
Chinese chives
Allium cepa var. cepa
Allium cepa var. aggregatum
Allium porrum
Allium sativum
Allium schoenoprasum
Allium tuberosum
Onions are liked as food and flavouring in Papua New Guinea but only some of them are
grown. Bulb onions are mostly imported. Shallots are grown quite widely on the coast and in the
highlands. Leeks are seen commonly in some areas of the highlands.
Onion family diseases
Bunching onion (A. fistulosum)
Leaf spot
Leek
Leaf blight
Onion
Leaf tip withering
Smudge
Soft rot
Shallot
Leaf tip burn
Leaf tip wither
Smudge
Fungus
Alternaria porri
Fungus
Alternaria porri
Fungus
Fungus
Bacteria
and
Alternaria porri
Colletotrichum circinans
Erwinia carotovora
Pseudomonas cepacia
Fungus
Fungus
Fungus
Alternaria porri
Sclerotinia fuckeliana
Colletotrichum circinans
Onion family insect pests
Black cutworm
Onion aphid
Onion thrips
Eating leaves of onion
Agrotis ipsilon (Hufnagel)
Neotoxoptera formosana (Takahashi)
Thrips tabaci Lind.
Helicoverpa assulta assulta
Bulb onion
Spring onion
Noctuidae
Aphididae
Thripidae
Noctuidae
LEPIDOPTERA
HEMIPTERA
THYSANOPTERA
LEPIDOPTERA
Leek
Chinese chives
Garlic
219
Fruit
Avocado
Bukubuk
Citrus
Custard apple family
Five corner
Indian mulberry
Golden apple
Guava & cherry guava
Laulaus (Syzygium spp.)
Lovilovi family
Mango
Marita
Mon (Dracontomelon)
Mulberry
Mundroi (Corynocarpus)
Myristica
Naranjilla
Tamarillo or tree tomato
Passionfruits & Granadilla
Pawpaw
Pineapple
Sugarcane
Ton (Pometia pinnata)
Watermelon
Bullock's heart
Cherimoya
Soursop
Sweetsop
Malay apple
Rose apple
Surinam cherry
Watery rose apple
221
224
226
233
235
238
240
242
249
244
246
253
256
255
254
257
258
261
265
267
269
270
272
275
279
284
287
296
298
Avocado
Tok pisin name: Bata
Scientific name: Persea americana
The plant
The avocado tree can grow up to 20 metres high and can be spreading or upright in shape.
The bark is grey and rough.
The leaves are entire and oval in shape. They are about 10 cm long. The leaves fall off
during some times of the year.
The flowers are about 1.5 cm wide and yellowish green in colour and near the ends of
branches in clusters. The flowers are produced in very large numbers and often only one fruit
forms for each 500 flowers. The fruit is oval shaped and green on the skin with one large seed
inside. The seed is covered with a brown papery skin. The flesh of the fruit is also greenish yellow.
The shape of the fruit and the colour of the skin can vary considerably. The fruit hang from stalks
often in a bunch.
It needs to be in a frost free location but can grow from sea level up to about 2250 metres
altitude. The wood is rather soft so branches can break off in strong wind. Some kinds of avocado
can grow in fairly salty soil.
Growing avocadoes
Avocado trees can be grown from seed. The seeds grow easily but are sometimes slow
growing. If they are planted in a nursery the young trees are ready for transplanting after 6 to 12
months. To be sure of getting a good quality fruit, grafted trees should be used. Seedling trees start
to produce fruit after about 5 or 6 years. Trees growing under good conditions should last for 50
years.
Fruit production tends to be seasonal and often trees produce larger crops every second year.
221
Pest and disease
Avocado diseases
Root rot
Leaf spot
Pink disease
Algal spot (red rust)
Sooty mould
Fungi
and
and
and
Fungus
Fungus
Alga
Fungus
Phytophthora cinnamomi
Phellinus noxius
Rigidoporus microporus
Fusarium solani
Corynespora sp.
Phanerochaete salmonicolor
Cephaleuros virescens
The trees can easily be damaged by root rot especially if they are in poorly drained soil.
Trees with this disease slowly start to look wilted and the leaves fall and the tree dies. When new
leaves are growing they are small and often yellow. If the roots are checked the smaller roots will
be sick or very few of them will be found. The fungus that causes the problem grows in soils with
temperatures between 10° and 30° C but are normally in wet and poorly drained soils. In Papua
New Guinea the Phytophthora cinnamoni fungus has not been recorded below about 750 metres
altitude but it is common in the highlands.
Shoots of trees can be killed out with Pink's disease. If this is noticed the branch should be
pruned out and then sprayed or painted with a fungicide chemical tridemorph.
Insect pests avocado
Abgrallaspis cyanophylli (Signoret)
Adoxophyes sp
Amblypelta spp.
Aspidiotus destructor Signoret
Ceroplastes destructor Newstead
Ceroplastes rubens Maskell
Chrysomphalus dictyospermi (Morgan)
Coccus hesperidium Linnaeus
Coccus longulus (Douglas)
Colgar tricolor Dist.
Dysmicoccus nesophilus Williams
Eupholus spp.
Euricania villica
Ferrisia virgata Cockerell
Fiorinia fioriniae (Targioni)
Gascardia destructor. De Lotto
Graphium agamemnon L.
Helopeltis clavifer (Walker)
Hemiberlesia lataniae (Signoret)
Hemiberlesia palmae (Cockerell)
Homeoxipha fuscipennis
Hyposidra talaca (Wlk.)
Icerya seychellarum (Westwood)
Idopsis grisea Faust.
Milviscutulus mangiferae (Green)
Milviscutulus spiculatus Williams
Morganella longispina (Morgan)
Oribius spp.
Paratella miniata Mcl.
Perissopneumon
Pinnaspis strachani (Cooley)
Planococcus citri (Risso)
Pseudodoniella typica China & Carvalho
Saissetia coffeae (Walker)
Selenothrips rubrocinctus (Giard)
Terentius nubifasciatus Walker
Xyleborus perforans (Wollastan)
Diaspididae (HEM)
Tortricidae (LEP)
Coreidae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Flatidae (HOM.)
Pseudococcidae (HEM)
Curculionidae (COL)
Ricaniidae (HEM.)
Pseudococcidae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Papilionidae (LEP)
Miridae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Gryllidae (ORTH)
Geometridae (LEP)
Margarodidae
Curculionidae (COL)
Coccidae (HEM)
Coccidae (HEM)
Diaspididae (HEM)
Curculionidae (COL)
Flatidae (HEM)
Diaspididae (HEM)
Pseudococcidae (HEM)
Miridae (HEM)
Coccidae (HEM)
Thripidae (THYS)
Membracidae (HOM)
Scolytidae (COL)
Armoured scales
Leaf roller
Amblypelta bugs
Coconut scale
Soft scale
Pink wax scale
Armoured scale
Soft brown scale
Soft scale
Mealy bug
Eupholus weevils
Plant hopper
Striped mealy bug
Armoured scale
Soft wax scale
Green spotted triangle
Cacao mirid
Armoured scale
Soft scale
Soft scale
Soft scale
Armoured scale
Shot hole weevils
Mealy bug
Armoured scale
Mealy bug
Coffee scale
Cacao thrips
Island pinhole borer
Avocado fruit as food
The flesh of the fruit is soft and can be spread like butter. It has a high oil content up to 25%
of the fresh weight. The fruit is good for feeding babies. The flesh of the fruit can be scooped out
with a spoon or stick and adding salt or pepper adds flavour.
Food value per 100 g edible portion
Moisture
Energy
%
KJ
Fruit
74.4
805
Protein
%
1.8
ProVit A
µg
480
Provit C
mg
11
Iron
mg
0.7
Zinc
mg
0.4
Avocadoes are one of the fruits with high food value especially protein. They are rich in
vitamins.
Fruit will not store for a long time.
223
Bukubuk
Tok Ples Kuanua: Bukubuk
Scientific name: Burckella obovata
What is a Bukubuk like?
A bukubuk fruit is a soft green fruit up to 15 cm across. The outside of the fruit has five or
so large fleshy lobes. Inside there is a hard pointed seed. The flesh of the fruit is white. It has a
texture and taste something like cantaloupe.
The fruit grows on a large tree that can be 36 metres high and have a trunk 2 m through.
The tree often has buttresses.
The branches have lots of twigs on them and the leaves are often crowded at the tips of these
small branches. The leaves are simple, produced one after another alternatively along the branch,
and they are shiny.
A white sticky sap is produced from the broken ends of twigs and leaves.
The flowers are in groups just back from the ends of the twigs. The flowers are small and
white. They have 4 sepals and a corolla with 8 lobes.
Where do bukubuk's grow?
They are truly tropical trees that mostly grow in the lowland rainforest. They occur as
occasional trees scattered through the rainforest, and are also planted.
These fruit trees occur on islands such as Manus, New Britain and North Solomons, and also
in other South Pacific countries such as Vanuatu.
How did it get its name?
The name Bukubuk is a Tolai word used by the people of the Gazelle Peninsula at Rabaul.
As the fruit are sold in the Rabaul market, this name is also known by a number of other people.
Bukubuk means lumpy, because the fruit has bumps on it. The fruit also grows in other areas of
PNG and has other Tok ples names.
Scientists have given it a Latin name Burckella obovata. This is the same in all languages
of the world. It belongs to a family of plants called Sapotaceae. These plants have milky sap in
them.
Tok Ples names
Papua New Guinea
Province
Manus
New Ireland
New Britain
North Solomons
Language
Kuanua
225
Tok ples name
Nanat
Natu
Bukubuk
Citrus or muli family
The plants in this family used for fruit in Papua New Guinea include:
Citrus aurantifolia
Lime
Citrus aurantium
Sour orange
Citrus grandis
Pomelo
Citrus hystrix
"Wild" citrus
Citrus limon
Lemon
Citrus medica
Citron
Citrus paradisi
Grapefruit
Citrus reticulata
Mandarin
Citrus sinensis
Sweet orange
Clymenia polyandra
Clymenia
Fortunella margarita
Kumquat
Triphasia trifolia
Lime berry
West Indian lime
Citrus aurantifolia
Sweet orange
Citrus sinensis
Grapefruit
Citrus paradisi
Mandarin
Citrus reticulata
Pomelo
Citrus grandis
Clymenia
Clymenia polyandra
Wild lime
Citrus hystrix
Lemon
Citrus limon
Pomelo
West Indian lime
Grapefruit
Citron
Clymenia
Orange
227
There are many books that deal in great detail with citrus as a crop so it is not intended to
deal with all the plants or details here. Only some notes will be included.
The majority of citrus in Papua New Guinea are seedling plants and as these do not breed
true to type the fruit is often of poor quality. As well at least in coastal areas they are subject to
many pests and diseases and so production if often very poor. Many citrus fruit in Papua New
Guinea do not develop true colour but remain green when ripe. They could be degreened but the
flavour remains the same.
If the purpose of growing a fruit like citrus is for the food value, there are far more nutritious
fruits such as guava that are easy to grow and more popular and much more nutritious.
Of the citrus, lime, pomelo and Clymenia reach levels of some significance in coastal areas
and on some of the islands. Lime berry is grown and enjoyed in some coastal areas such as near
Rabaul and is enjoyed. Clymenia polyandra is an indigenous citrus occurring only in Papua New
Guinea and only on some of the islands. Citrus hystrix or "wild" citrus is cultivated in some coastal
areas but only used for flavouring drinks. Of the subtropical species lemon, orange and mandarin,
there is sometimes reasonable production in a few mid altitude areas.
Growing citrus
Citrus seed normally germinates and starts growing in about 3 or 4 weeks. For good citrus
production it is best to bud selected material onto an appropriate rootstock. Some of the research
stations provide planting material.
Flowering in citrus continues throughout the year in the tropics except where rainfall or
drought causes fluctuations in flowering and fruiting.
Fruit matures quickly under the warm conditions in much of Papua New Guinea. For
example oranges are mature in 6 months, but the quality is poor.
Lime berry
Kumquat
With citrus several plant nutrients needed in small amounts can become short and these
quickly show up as poorly growing or poorly coloured leaves. Common deficiencies are zinc,
manganese and copper. Boron deficiency is common on acid soils with high rainfall. Citrus will
grow on soils of a range of acidity from 5.5 to 8.0 but they will not tolerate waterlogged soils.
Citrus will grow between temperatures of about 12°C and 30°C but they are mostly sensitive
to frost especially during flowering. So the best altitude range for citrus is about 800 to 1200
metres except for Pomelo and Clymenia that will grow nearer the coast. In several areas the West
Indian lime grows quite well near the coast. Citrus normally grows best where it has full sunlight.
Where the rainfall is even and the temperature remains fairly even citrus flowers most consistently.
A rainfall between 1000 and 2000 mm is best.
There are a large range of diseases and pests that get on citrus.
Citrus pests
Agrilus occipitalis Esch
Buprestidae (COL)
Amblypelta theobromae Brown
Coreidae (HEM)
Tip wilt bug
Aonodiella aurantii Mask.
Coccidae (HEM)
Red scale
Aonidiella citrina (Coq)
Diaspididae (HEM)
Yellow scale
Coccus viridis (Green)
Coccidae (HEM)
Green scale
Dacus cucurbitae Coq.
Tephritidae (DIPT)
Melon fruit fly
Dacus tryoni Frogg
Tephritidae (DIPT)
Queensland fruit fly
Eudecatoma sp.
Eurytomidae (HYMEN)
Wasp
Homona coffearia Nietn.
Tortricidae (LEP)
Coffee leaf roller
Leptoglossus australis (Fabricius)
Coreidae (HEM)
Black leaf footed bug
Mictis profana F.
Coreidae (HEM)
Crusader bug
Oribius cinereus Mshl.
Curculionidae (COL)
Shot hole weevils
Oribius cruciatus Fst.
Curculionidae (COL)
Shot hole weevils
Oribius destructor Mshl.
Curculionidae (COL)
Shot hole weevils
Oribius inimicus Mshl
Curculionidae(COL)
Shot hole weevils
Papilio aegeus ormenus Guerin
Papilionidae (LEP)
Citrus butterfly
Phyllocnistis citrella Staint
Phyllocnistidae (LEP.)
Citrus leaf miner
Planococcus citri (Risso)
Pseudococcidae (HEM)
Citrus mealy bug
Rhinoscapha thomsoni Wterh.
Curculionidae (COL)
Citrus leaf eating weevil
Rhopalosiphum maidis (Fitch.)
Aphididae (HEM)
Corn leaf aphid
Saisettia coffeae Walker
Coccidae (HEM)
Brown coffee scale
Spodoptera litura (Fab)
Noctuidae (LEP)
Cluster caterpillar
Tiracola plagiata (Walker)
Noctuidae (LEP)
Cacao armyworm
Toxoptera aurantii B.de Fonsc.
Aphididae (HEM)
Black citrus aphid
Toxoptera citricidus (Kirk)
Aphididae (HEM)
Brown citrus aphid
Unaspis citri (Comst.)
Diaspididae (HEM)
White louse scale
Several other mealbugs occur in Papua New Guinea and also get on citrus. These include: Dysmicoccus nesophilus,
Ferrisia virgata, Laingiococcus painei, Maculicoccus malaitensis, Nipaecoccus viridus, Planococcus lilacinus,
Planococcus pacificus, Pseidococcus elisae, Pseudococcus longispinus, Rastrococcus vicorum.
There are also several other soft scales in Papua New Guinea that get on citrus. These include: Icerya purchasi, Icerya
seychellarum, Steatococcus samaraius, Anthococcus kerevatae, Ceroplastes destructor, Ceroplastes rubens, Coccus
hesperidium, Coccus longulus, Drepanococcus chiton, Kilifia acuminata, Milviscutulus mangiferae, Parasaissetia
nigra, Pulvinaria psidii, Saissetia miranda, Saissetia neglecta, Vinsonia stellifera.
And there are several other armoured scales that occur in Papua New Guinea and get on citrus. These include:
Aonidiella eremocitri, Aspidiotus destructor, Aspidiotus excisus, Chrysomphalus aonidum, Chrysomphalus
dictyospermi, Chrysomphalus pinnulifer, Duplaspidiotus claviger, Fiorinia coronata, Fiorinia fioriniae, Hemiberlesia
lataniae, Hemberlesia palmae, Howardia biclavis, Ischnaspis longirostris, Lepidosaphes beckii, Lepidosaphes gloverii,
Lepidosaphes tokionis, Lopholeucaspis baluanensis, Morganella longispina, Parlatoria proteus, Pinnaspis buxi,
Pinnaspis strachani, Pseudaulacaspis pentagona.
229
Diseases of the Citrus family
Citron
Scab
Algal spot
Clymenia citrus
Scab
Grapefruit
With leaf spot
Algal leaf spot
Bacterial canker
Unthrifty plants
Lemon
Leaf spots
Scab
Pink disease
Bacterial canker
Lime
Sooty mould
Pink disease
Collar & root rot
Bacterial canker
Mandarin
Sooty mould
Pink crust of stems
Orange
Pink disease
Unthriftiness
Pomelo
Collar rot
Fungus
Alga
Sphaceloma fawcettii
Cephaleuros virescens
Fungus
Sphaceloma fawcettii
Fungus
Alga
Bacteria
Nematode
Glomerella cingulata
Cephaleuros virescens
Xanthomonas campestris
Tylenchulus semipenetrans
Fungi
and
Fungus
Fungus
Bacteria
Ascochyta citri
Glomerella cingulata
Sphaceloma fawcettii
Phanerochaete salmonicolor
Xanthomonas campestris
Fungus
Fungus
Fungus
Bacteria
Meliola citricola
Phanerochaete salmonicolor
Phellinus noxius
Xanthomonas campestris
Fungus
Fungus
Meliola citricola
Podonectria sp
Fungus
Nematode
Phanerochaete salmonicolor
Tylenchulus semipenetrans
Fungus
Athelia rolfsii
Because many of these pests and diseases are common and serious, in my opinion, if you are more
interested in growing food than growing insects and diseases then I think there are more useful
crops for Papua New Guinea than citrus! There are many plants with much higher Vitamin C than
citrus.
Food value of 100 g of edible portion - fruit
Scientific name
Common name
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
Citrus aurantifolia
Citrus aurantium
Citrus grandis
Citrus hystrix
Citrus limon
Citrus limon
Citrus medica
Citrus paradisi
Citrus reticulata
Citrus sinensis
West Indian lime
91.0
86.0
89.1
133
205
159
0.7
0.9
0.76
4
4
0
40
53
61.0
0.25
0.5
0.11
0.1
83.3
91.3
90.2
43.5
87.6
86.8
65
31
170
45
184
197
1.1
0.3
0.7
0.3
1.5
0.94
Tr
Tr
80
50
53
19
136
53.2
0.4
0.1
0.5
0.1
0.8
0.1
0.1
Tr
0.1
0.1
Sour orange
Pomelo
Wild lime
Lemon
Lemon
Citron
Grapefruit
Mandarin
Orange
Tr
42RE
21
0.1
0.1
231
Custard apple family
Four or five fruits in this group of plants are grown for their edible fruits in Papua New
Guinea. Sometimes they are called Custard apples but because this name is used for different ones
at different times it is best to use other separate names. The names used here are:
English name
Bullock's heart
Cherimoya
Soursop
Sweetsop
Atemoya
Tok Pisin
Sapasap
Scientific name
Annona reticulata
Annona cherimolia
Annona muricata
Annona squamosa
A.cherimola x A.squamosa
In other tropical countries there are about 8 other fruit trees in this group called Annona that are
grown for their edible fruit.
Atemoya
Bullock’s heart
Soursop
Sweetsop
Pest and disease
Diseases of the Custard apple family
Plant
Custard apple (See Sweetsop)
Soursop
Disease
Cause
Scientific name
Sooty mould
Pink disease
Blossom blight
Algal leaf spot
Fungi
and
and
Fungus
Fungus
Alga
Capnodium sp
Chaetothyrium sp.
Microxyphium sp.
Phanerochaete salmonicolor
Glomerella cingulata
Cephaleuros virescens
Blossom blight
Pink disease
Fungus
Fungus
Glomerella cingulata
Phanerochaete salmonicolor
Sweetsop
Insect pests of Custard apple family
Abgrallaspis cyanophylli (Signoret)
Adoxophyes sp.
Amblypelta spp.
Anthococcus kerevatae Williams
Apirocalus spp.
Aspidiotus destructor Sign.
Aleurodicus destructor (Mackie)
Chrysomphalus aonidum (Linnaeus)
Coccus celatus De Lotto
Coccus longulus (Douglas)
Dasychira mendosa Hubn.
Drepanococcus chiton (Green)
Dysmiccocus brevipes (Cockerell)
Euricania villica
Ferrisia virgata (Cockerell)
Graphium agamemnon L.
Hemisphaerinus sp.
Hemiberlesia palmae (Cockerell)
Homona coffearia Nietn.
Howardia biclavis (Comstock)
Hyposidra talaca (Wlk.)
Icerya seychellarum (Westwood)
Laingiococcus painei (Laing)
Oribius cinereus Mshl.
Parasaissetia nigra (Nietner)
Pinnaspis strachani (Cooley)
Planococcus lilacinus (Cockerell)
Planococcus pacificus Cox
Pseudococcus longispinus Targioni
Saissetia coffeae (Walker)
Steatococcus samaraius Morrison
Terentius nubifasciatus Walker
Unaspis citri (Comstock)
Diaspididae (HEM)
Tortricidae (LEP)
Coreidae (HEM)
Coccidae (HEM)
Curculionidae (COL)
Diaspididae (HEM)
Aleyrodidae
Diaspididae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Lymantriidae (LEP)
Coccidae (HEM)
Pseudococcidae (HEM)
Ricaniidae (HEM)
Pseudococcidae (HEM)
Papilionidae (LEP)
Issidae (HEM)
Diaspididae (HEM)
Tortricidae (LEP)
Diaspididae (HEM)
Geometridae (LEP)
Margarodidae (HEM)
Pseudococcidae (HEM)
Curculionidae (COL)
Coccidae (HEM)
Diaspididae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Coccidae (HEM)
Margarodidae (HEM)
Membracidae (HOM)
Diaspididae (HEM)
233
Armoured scale
Leaf roller damaging soursop
Amblypelta bugs
Soft scale
Horned weevil
Coconut scale
Coconut white fly
Florida red scale
Soft scale
Soft scale
Caterpillar eating leaves soursop
Wax scales Attended by ants
Pineapple mealybug
Plant hopper sucking sap of soursop
Green spotted triangle
Sucking sap of soursop
Armoured scale
Coffee leaf roller
Armoured scale
Eating leaves of custard apple, soursop
Scale
Shot hole weevils
Nigra scale
Armoured scale
Mealy bug
Mealy bug
Longtailed mealybug
Coffee scale
Scale
Sap-sucker of soursop
White louse scale
Bullock's heart
Scientific name: Annona reticulata
What is the plant like?
The Bullock's heart is a small tree up to 7.5 m tall. It has several branches near the base.
New shoots have short brown hairs but older wood is smooth and shiny. Trees loose their leaves at
some times of the year.
It has spear shaped leaves. They have short leaf stalks. Around the edge of the leaf is a
clear edge. Leaves smell when crushed.
The flowers are greenish yellow. They occur in groups where the leaves join the stalk.
They occur on new wood growth.
The fruit are round and about 10 to 12 cm across. They are yellowish brown in colour.
Over the surface of the fruit there is a fine hexagonal pattern. There are large brown seeds inside
the fruit. The flesh is yellow. The fruit are eaten raw.
Where is the Bullock's heart grown?
The Bullock's heart is a tropical plant. It occurs in the lowlands and up to about 1200 metres
altitude. It occurs around some coastal towns.
It is less suited to dry climates.
How do you grow Bullock's heart?
Mostly trees are grown from seed. These trees vary quite a bit. Seedlings are easy to
transplant. Trees need to be about 7 m apart.
Better kinds can be grown using budding or grafting.
Trees begin to produce fruit after about 3 to 5 years. Trees flower and produce fruit
throughout the year.
235
Cherimoya
Scientific name: Annona cherimola
What is the plant like?
This is a small tree up to 6 m tall. It grows new shoots from the branches after the leaves
fall.
The leaves are quite large (10 cm x 25 cm) and are light green. Underneath the leaves are
densely covered with short soft hairs.
Flowers usually occur singly on young and old wood. They are long (2.5 cm) and narrow.
Fruit are up to 15 cm long and 10 cm wide. The fruit is fairly round but covered with many
fleshy, scale like parts. The outside of the fruit can be dark green to black. Dark brown seeds about
1 cm long are inside the flesh. The flesh around the seeds is eaten.
Where does it grow?
The cherimoya is better suited to slightly cooler places and to drier climates. Therefore it
does better in the hills than on the coast. It will probably grow well at about 1000 m altitude and
may grow up to about 2300 m.
How do you grow cherimoya?
Trees are mostly grown by using seed. Seeds can be stored for several years and will still
grow or they can be planted fresh. Seeds grow in about 4 weeks. Seedlings can be transplanted
when one year old. They are easy to transplant and even trees 3 or 4 years old can be transplanted
when the leaves have fallen off.
Cherimoya
seeds
For better kinds of trees it is necessary to use budding or grafting.
Trees can be spaced 8 metres apart. They can be pruned to give a better-shaped tree.
Hand pollination of the flowers can give more even shaped fruit and also ensure more fruit
are formed. To do this, flowers are gathered in a small brown paper bag and kept till the pollen
falls. Then with a small brush the pollen is put on freshly open flowers. The three petals of the
flower are gently held open and the pollen spread around on the female flower parts (pistils).
Food value of 100 g edible portion:
Edible portion
Fruit raw
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
73.5
395
1.3
1
9
0.5
237
Zinc
mg
Soursop
Scientific name: Annona muricata
The plant
Soursops or sapasap are small coastal trees that have been introduced to Papua New Guinea
originally from South America. The trees are up to 5 or 6 metres high and have low branches with
limbs that turn upwards giving the tree a slender look. The bark is brown and smooth. The tree has
leaves all year round.
The leaves are long (14 cm) and narrow (4 cm) slightly shiny on top and without hairs. The
leaves are carried one after the other on opposite sides of the branches. The leaves feel thick and
like leather.
The flowers are large (2-3 cm long), rounded and produced on short stems on the branches.
The flowers have thick yellow petals. Mostly only one or two flowers are produced together.
The fruit is large and has soft spines over its surface. The fruit can be 15 to 25 cm long and
can weigh up to 2 kg. The fruit is dark green in colour, soft and fleshy and heart shaped but often
with one side flattened.
Inside, the fruit has many black seeds scattered through the white juicy pulp. Not all of the
segments of the fruit have a seed in them. Seeds are commonly 1 to 2 cm long. The fleshy pulp has
fibres in it.
The leaves, fruit and flowers can all have a slightly unpleasant smell.
Drawing by Celia Bridle
Where do soursops grow?
Soursops are a tropical plant. They grow best in the hot lowlands. They are mostly grown
from sea level up to about 1000 m altitude. In Papua New Guinea they are seen around many
coastal towns.
The trees can withstand temperatures down to freezing (0°C) for a short time but salt laden
winds from the sea can kill the trees.
They need a well-drained soil and cannot tolerate waterlogging. The trees continue to grow
and produce satisfactorily in fairly poor compact soil. But improving the fertility increases the
amount of fruit.
They can grow well in hot humid areas but a fungus disease called Blossom blight can cause
flowers to fall off.
How do you grow soursops?
Plants can easily be grown from seeds. Seeds can be planted fresh or stored. Seeds grow in
about 15 to 20 days. Trees grown from seeds vary in the quality of the fruit.
Trees can also be grown from cuttings or by grafting. This allows better trees to be selected
and produced.
Trees need to be about 5m apart.
Hand pollination of flowers can increase the number of fruit that are produced.
How well do trees produce?
Trees grow quickly. They can start producing fruit in 3 or 4 years.
Trees flower and fruit throughout the year but there is normally one season when more fruit
are getting ripe. Often a tree only produces 12 to 20 fruit in a year.
Soursop as food
The fruit contain 81% moisture and 12.7% total sugars. The fruit have 0.4% protein. The
flesh of the fruit is therefore juicy and somewhat sweet but with a sour taste due to the amount of
acid they contain.
Soursop seeds are poisonous.
Pest and Disease
In Papua New Guinea trees are often infested with scale insects and mealy bugs. Red ants
live in connection with these insects in many places so that trees and branches are often covered
with ants. As well, these scale insects and mealy bugs leave behind them a liquid called honey dew.
A black sooty mould fungus then grows on the leaves where the honeydew occurs. As a result,
leaves are commonly covered by a black sooty mould. The mould can be rubbed off with the
fingers as it only grows on the surface of the leaf. If the scale insects are controlled the sooty mould
stops growing.
In wet humid places another fungus grows on the flowers and causes them to fall off. This
is called Blossom blight and is due to a fungus (Colletotrichum gloeosporoides Penz.). Improving
the growing conditions and allowing more sunlight in by pruning can help reduce the amount of
damage by this disease.
239
Sweetsop
Scientific name: Annona squamosa
Names.
Sometimes this fruit is also called a custard apple. But as custard apple is also used
occasionally for other fruits in this same group, particularly the atemoya, it is less confusing to refer
to this fruit as the sweetsop.
What is a sweetsop like?
The tree is a small tree that can be up to 6m high and it has irregularly spreading branches.
The leaves are oblong and narrow and often about 12 cm long by 4 cm wide. The leaves
have fine hairs underneath. The leaves smell when crushed. They are a dull green colour.
The flowers droop or hang down from the branches either singly or in groups of 2 or 3. The
flowers are a greenish colour.
The fruit are 8-10 cm across and green in colour. The outside is made up of loosely
overlapping fleshy parts of the female flower (carpels).
Inside the fruit there are several shiny black seeds about 1.5 cm long. These seeds are
amongst the white soft flesh of the fruit.
Where do sweetsops grow?
Sweetsops occur in the tropical lowlands. They are common and grow naturally on some of
the dry hills around Port Moresby. But sometimes in these hot dry areas trees do not set fruit well.
Fruit production is often better in places with a more humid atmosphere. Trees fruit well at Bulolo.
The trees will probably grow satisfactorily up to about 1000 metres altitude.
Sweetsops cannot stand frost but they are able to survive droughts better than many fruit
trees. Trees do not like waterlogged soils. Sweetsops can grow on fairly poor dry stony soils.
Trees often lose their leaves in the dry season.
How do you grow sweetsops?
Sweetsops are mostly grown from seeds. Seeds can be stored for several years and will still
grow. But it is better to use fresh seeds if they are available. Seeds germinate and start to grow 50
to 70 days after planting. Soaking the seeds for 3 days in water often helps them to grow.
Trees can start to produce fruit 2 years after they are planted.
If you want to save and grow a particularly good kind of sweetsop, it is better to use
methods such as grafting than to sow seeds. A small branch is grafted onto the roots and tree of
another sweetsop plant that is already growing. By this method, the new branch will grow and
produce fruit exactly the same as the tree it came from. Plants are very hard to get to grow from
cuttings. A spacing of 6 m apart is suitable for sweetsop trees.
How are the fruit used?
The sweet soft fleshy layer around the seeds can be eaten raw. When the fruit is ripe it is
easy to separate the different soft fleshy parts of the fruit.
Often it is easiest and best to harvest the fruit when they are nearly ripe and then let them
ripen in a warm place.
The seeds, leaves and roots are poisonous. Both a chemical called an alkaloid, and
hydrocyanic acid have been shown to occur in these parts of the plant.
241
Five Corner or Carambola
Scientific name: Averrhoa carambola
What is the tree like?
The five-corner tree is a small tree which can grow up to 12 m tall. It has a nice shady
crown of leaves. The trunk of the tree is short or crooked and has branches near the base. The bark
is smooth and dark grey. The tree has many branches and the twigs bend easily and tend to hang
down.
A leaf is made up of 2 to 11 leaflets. There is a leaflet at the end so that an uneven number
of leaflets occur. The leaves are darker green and more shiny on top. The leaflets don't occur
exactly opposite each other along the stalk. Also leaflets get larger as they go along the stalk. The
leaflets are uneven in shape, one side being broad and the other narrow. The leaves tend to hang
flat if the tree is shaken and at night the leaves also hang close together.
The flowers are small (8 mm long) and red and white in clusters or groups on the small
twigs and branches. The flowers have 5 petals and 5 sepals. The flowers have a sweet smell.
The fruit is a star shaped or 5 angled fleshy fruit. The colour becomes yellow to orange as
fruit ripen. The fruits are waxy in appearance and you can almost see through them. They are
smooth and thin skinned. Fruit can be 10 cm or more long. The flesh of the fruit is very juicy with
a sweet sour taste. They also have a scented perfume or smell.
In the bottom section of each lobe of the fruit there are 1 or 2 seeds. The seeds are shiny,
thin, light brown and about 1 cm long.
Where do five corners grow?
Five corners need a warm tropical climate so they are mostly seen in the coastal lowlands
below about 500 m altitude. They will grow up to 1200 m.
Five corner can grow on several different types of soil. The soil should be well drained.
It is suited to moist places but performs better in areas where there is some dry season rather
than in places with heavy, constant rain.
Trees are fairly wind resistant providing the winds are not cold.
Trees can start bearing after 3-4 years.
How do you grow five-corner?
Many five-corner trees in Papua New Guinea have been grown from seeds. This is the
easiest way to grow a tree but sometimes the fruit is sour and not as enjoyable to eat. Seeds grow
easily but in fact only a small number of seeds are fertile. Well-developed seeds should be chosen.
Because seeds are produced from pollen coming from other flowers (cross pollination), not all the
seedlings that grow will be the same.
To avoid this problem and to produce fruit of the better, sweeter kinds it is necessary to use
specialised vegetative methods of growing new trees. Taking buds off good trees, or grafting twigs
from them, onto 1-year old seedling roots is the commonest method.
Trees live for a long time and fruit is produced at most times of the year. Flowers and fruit
can be found on the tree at most times of the year. Flowers and fruit can be found on the tree at
most times although there is often 2 or 3 main flushes of flowering and fruiting.
The tree does not require pruning or any special care once established.
Flowers are cross-pollinated by bees, flies and other insects. Hand pollination does not help
fruit set much.
243
Golden apple
Scientific name: Spondias cytherea
What is a Golden apple like?
Often a Golden apple tree grows to a large tree that can be up to 30 m high but is more often
15 m high in cultivation. It has a trunk 60 cm across which can have buttresses. The bark on the
trunk of the tree is fairly smooth. The twigs break off easily. The wood is soft and not much use.
The leaf is made up of 4 to 12 pairs of leaflets that have fine teeth around the edge. The
leaves are smooth and dark green on top and pale green underneath. The leaves of the tree fall off
for a part of the year. The old leaves wither to a bright yellow colour.
The flowers are produced near the ends of the branches and mostly the flowers develop
before the new young leaves grow. The flowers occur as several flowers on long stalks. They are
small and white. They look something like a mango flower.
The fruit is yellow, oval and up to 7 cm long and 4 cm across. Sometimes the outside of the
fruit has a mottled black colour. There is one large stone inside divided into 5 cells with a seed in
each. The stone is branched and has fibres.
Where do Golden apples grow?
This fruit tree occurs commonly both wild and cultivated in lowland rainforest areas
throughout Papua New Guinea. It covers the full range from wild unused fruit trees in the forest to
a planted, pruned and highly regarded village fruit tree. The wild trees are probably spread around
by birds, pigs and people.
Naturally, trees mostly occur on deep alluvial soils and are rare on thin limestone soils.
They are in well-drained soils or in dry forests. Trees grow from sea level up to about 950 m
altitude. Trees can start to fruit after about 4 years. Fruiting is seasonal.
The trees also grow in Indonesia, the Philippines, Thailand and a number of other Pacific
countries. It has also been taken to other tropical countries.
Names
Some of the Tok Ples names for his plant are:
Place
Manus
Kavieng
Rabaul
Lake Kutubu
Madang
Name
drine
kulis
kru or kuris
kinaio
huneg
The older scientific name for this plant was Spondias dulcis
How are Golden apples grown?
Trees are mostly grown from seed. The seeds do not produce true to type so that poor and
sour fruit are often produced. It is possible to grow plants from cuttings although it is difficult.
Doing this would enable better types of fruit to be regrown. It can also be grown using budding.
Young trees benefit by shade during their first year. The top can be cut off trees to give a
lower and more spreading tree.
Insect pests of Golden apple
Coconut scale
Aspidiotus destructor Sign.
Armoured scale
Chrysomphalus dictyospermi (Morgan)
Armoured scale
Hemiberlesia palmae (Cockerell)
Icerya seychellarum (Westwood)
Mealy bug
Planococcus pacificus Cox
The insect pests on Golden apple have probably not been properly studied.
How is Golden apple used?
The fruit are eaten raw after the sour skin is peeled off. Sometimes lime is added to the
fruit. The fruit is sour. It has the texture of an apple. Sometimes the fruit is eaten with salt or
mixed with coconut. Fruit production is seasonal probably early in the year. The young leaves of
the tree are eaten often raw but also cooked.
The food value of fruit per 100 g edible portion
Moisture
Energy
Protein
ProVit A
%
KJ
%
µg
70.0
657
0.6
245
Provit C
mg
Iron
mg
Zinc
mg
Guava
Scientific name: Psidium guajava
Guava trees
Trees grow between 3 and 10 m tall. They have thin trunks and straggly branches. The
bark is smooth and peels off in thin flakes. The tree branches close to the ground and can have
suckers around the base.
Leaves are produced in pairs opposite each other. The leaves are smooth, light green in
colour and with distinct veins. They are about 15 cm long.
The young twigs are four angled.
Flowers are produced where the leaves join the branches. The fruit is green but becomes
yellow/orange when fully ripe.
Growing guavas
Most of the guava trees in Papua New Guinea have been grown from seed or have just
grown naturally from seed scattered by birds and bats. To get really good quality fruit it is
necessary to grow trees using budding, grafting, cuttings of stems or roots, or by air layering. This
enables trees exactly the same as the original trees to be produced. If vegetative methods are to be
used it is as well to look up the details of the methods in other books as these methods do not
always work easily with guava. Better fruit have thinner skins, fewer seeds and less of the tough
"stone" cells.
On fruit can produce about 50 seeds for sowing. Seeds will still grow after a year or more,
but it is best to plant them while fresh. Guavas come up when land is cleared and grow easily in
grassland. Seeds normally start to germinate in 2 or 3 weeks. Guavas can produce fruit after about
3 years and keep producing for up to 30 years.
Pruning back the tips of guava branches (about 10 cm) increases the yield of fruit.
Guavas produce more and better fruit if the trees are well looked after and the soil fertility
improved. This can be done with animal manures or commercial fertilisers. Spraying the trees with
1% urea solution onto the leaves has helped flower and fruit formation.
Flowering occurs throughout the year. It takes about 5 months from flowering until fruit are
ready.
Where guavas grow
Guavas grow well up to an altitude of about 1600 m and will grow easily on a range of soils
and in different climates. It suits the lowlands and can't stand frost. It is not greatly troubled by
temporarily waterlogged soils and can survive some drought. It will grow on fairly poor and acid
soils.
Guavas grow best when the average temperature is between 23°C and 28°C.
Guavas as food
Guavas have very high levels of vitamin C and are much better than citrus for this. Because
the vitamin C level is high near the skin, the method used especially by children of eating the fruits
skin and all is a good method. Guavas also make good jellies, and juice.
The food value per 100 g edible portion of the fruit
Edible portion
Moisture Energy Protein
ProVit A
%
KJ
%
µg
Fruit
77.1
238
1.1
60
247
Provit C
mg
184
Iron
mg
1.4
Zinc
mg
0.2
Insects
Fruit flies can damage guavas. The maggots of the flies bore in the fruit.
Guava insect pests
Amblypelta bugs
Banana fruit fly
Brown coffee scale
Cacao mirid
Coconut scale
Spiralling whitefly
Striped mealybug
Weevil
Fruit flies
Moth larvae
Mealybug
Mirid sap-sucker
Moth
Armoured scales
Amblypelta spp.
Bactrocera musae and Bactrocera bryoniae
Saissettia coffeae
Helopeltis clavifer
Aspidiotus destructor
Aleurodicus dispersus
Ferrisia virgata
Apirocalus cornutus
Bactrocera frauenfeldi, B. trivialis
Lymantria rosina
Perissopneumon sp.
Ragwellelus festivus
Syntherata janetta
Abgrallaspis cyanophylli
Chrysomphalus dictyospermi
Hemiberlesia lataniae
Hemiberlesia palmae
Unaspis citri
Icerya purchasi
Steatococcus samaraius
Ceroplastes destructor
Coccus longulus
Eucalymnatus tessellatus
Parasaisettia nigra
Pulvinaria psidii
Saisettia neglecta
Dysmicoccus brevipes
Dysmicoccus nesophilus
Planococcus citri
Planococcus pacificus
Rastrococcus vicorum
Coreidae (HEM)
Tephritidae (DIPT)
Coccidae (HEM)
Coreidae (HEM)
Diaspididae (HEM)
Aleurodidae (HEM)
Pseudococcidae (HEM)
Curculionidae (COL)
Tephritidae (DIPT)
Lymantriidae (LEP)
Miridae (HEM)
Saturniidae (LEP)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Margarodidae (HEM)
Margarodidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Soft scales
Mealybugs
Guava diseases
Fruit rot
Fruit canker
Fruit rot
Algal spot
Fungus
Fungus
Fungus
Alga
Botrydiplodia theobromae
Pestalotiopsis psidii
Sclerotium rolfsii
Cephaleuros virescens
Pest and disease do not appear to be a major problem with Guava. In some areas of the
country guava grow very easily.
Indian Mulberry
Scientific name: Morinda citrifolia
What is the plant like?
The Indian mulberry tree is a small tree up to 4 or 5 metres high.
The leaves are produced opposite each other and leaves can often be 25 to 30 cm long.
They are thick, shiny and dark green.
The white flowers are in a round head and only one flower is in bloom at a time. It has 5
white petals on the end of a green tube.
The fruit is about 5 to 10 cm long. It is made up of several small fruit fused together to give
an appearance a little like the divisions on the skin of a pineapple. The fruit starts off green but
becomes white when ripe. Mostly the edible flesh surrounds a large number of kernels. The ripe
fruit develops a bad smell.
249
Where do Indian Mulberries grow?
In Papua New Guinea, these trees grow wild in the bush, at least along the Northern Coast
of New Guinea in the Sepik and New Britain areas. Mostly selfsown plants, they are near sea level
and up to about 30 metres altitude.
But they are also grown as fruit trees and can be cultivated up to 500 metres altitude. They
do well in areas with limestone rocks. They need to grow in well-drained soil and often do well in
dry places.
The tree grows in countries from the Pacific to India.
How do you grow Indian mulberry?
Trees often grow naturally from seed. Seed float easily in water and often grow along
foreshores. Fruit is produced year round.
Use
The green fruit can be used as a vegetable. The ripe fruit can be eaten raw. It is usually
collected after it falls from the tree. A drink can be made from the juice.
The young leaves can be cooked, or eaten raw. They can be used as a wrapping to cook
food in, and then the wrapping leaves eaten as well.
The bark of the tree yields a red dye, the root a yellow dye.
It is not a popular or important food but is used in times of scarcity.
Scale insects and mealy bugs on Indian mulberry
Aonidiella comperei McKenzie
Chrysomphalus aonidum (Linnaeus)
Hemiberlesia lataniae (Signoret)
Hemiberlesia palmae (Cockerell)
Pinnaspis bux (Bouche)
Pinnaspis strachani (Cooley)
Pseudaulacaspis pentagona (Targioni)
Coccus viridus (Green)
Eucalymnatus tessellatus (Signoret)
Milviscutulus mangiferae (Green)
Milviscutulus spiculatus Williams
Parasaissetia nigra (Nietner)
Pulvinaria psidii Maskell
Saissetia coffeae (Walker)
Saissetia miranda (Cockerell & Parrott)
Dysmicoccus nesophilus Williams
Planococcus pacificus Cox
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Florida red scale
White scale
Green scale
Nigra scale
Coffee scale
Malay apple & laulaus
A group of fruit trees in Papua New Guinea are often called laulaus in Tok Pisin. The
naming in Tok Pisin, English and among scientists is confused for the plants in this group. It is not
even certain how many different ones have fruit which are eaten in Papua New Guinea. The most
likely ones, and the names used in this article are:
English
Malay apple
Rose apple
Watery rose apple
Giant laulau
Java apple
Surinam cherry
Scientific name
Syzygium malaccensis L.
Syzygium jambos L.
Syzygium aquea Burm.f.
Syzygium megacarpa Craib
Syzygium javanica Lam.
Eugenia uniflora L.
By some scientists the name Eugenia is used instead of the name Syzygium for the same
plants. It seems that the name Syzygium is the correct name for the plants grown in the Asia Pacific
region.
Name
Watery rose
apple
Rose apple
Tree height
3-10 m
Java apple
5-15 m
Malay apple
5-20 m
Surinam cherry
2-7.5m
Fruit shape
7.5-10 m
Leaf shape
10-16 cm long
4-8 cm wide clasp stem
12-20 cm long narrow,
pointed
12-25 cm long
4-10 cm wide
15-50 cm long
7-20 cm wide
2.5 - 5 cm long
Flowers
White
Grown by
Seed or air
layering
Seed or cuttings
Yellow
White or pale
yellow
Red
Seed
Seed or cuttings
Small and white
Seed or cuttings
There are probably other species in this family also grown and used for their edible fruit in
Papua New Guinea especially down in the Western Province near Balimo.
The ones most commonly used in Papua New Guinea seem to be the Malay apple, Watery
rose apple and Surinam cherry. These will be described in more detail.
Watery rose apple
Rose apple
Malay apple
251
Surinam cherry
Pest and disease
Gelechiidae (LEP)
Idiophantis chirodaeta
Pseudococcidae (HEM)
Planococcus pacificus
Coccidae (HEM)
Icerya seychellarum
Coccidae (HEM)
Anthococcus kerevatae
Coccidae (HEM)
Ceroplastes ceriferus
Coccidae (HEM)
Coccus longulus
Coccidae (HEM)
Kilifia acuminata
Coccidae (HEM)
Milviscutulus mangiferae
Coccidae (HEM)
Pulvinaria psidii
Coccidae (HEM)
Vinsonia stellifera
Armoured scales
Diaspididae (HEM)
Abgrallaspis cyanophylli
Diaspididae (HEM)
Aspidiotus destructor
Diaspididae (HEM)
Chrysomphalus dictuospermi
Diaspididae (HEM)
Hemiberlesia lataniae
Diaspididae (HEM)
Hemiberlesia palmae
Diaspididae (HEM)
Lepidosaphes rubrovittata
Diaspididae (HEM)
Morganella longispina
The scales and mealy bugs suck sap, spoil fruit and help produce sooty mould
Causing galls on leaves
Mealy bugs
Soft scales
Diseases
Diffuse leaf spot
Sooty moulds
Chaetothyrium womersleyi
Brooksia tropicalis
Fungi
And
Rose apple
Watery rose apple
Malay apple
Surinam cherry
Malay apple
Tok Pisin: Laulau
Scientific name: Syzygium malaccensis
What is the plant like?
This is a medium sized tree up to 20 m tall. The tree is cone shaped with branches being
shorter near the top.
The leaves are dark green, thick and glossy. The leaves have short thick leaf stalks.
The flowers are in showy clusters with bright red stamens. These fall off and form a carpet
of red under the tree.
The fruit are up to 8 cm long, rounded in shape and white to red in colour. The skin is thin
and the flesh crisp, white and juicy. The fruit contains one round seed.
253
Watery rose apple
Scientific name: Syzygium aquea
What is the plant like?
The tree is between 5 and 10 metres tall. The twigs are angular.
The leaves are in opposite pairs, pointed and large (up to 20 cm long). Often the leaves
don't have a leaf stalk and they clasp the stem. They are shiny on both sides. The leaves are light
green.
Flowers are white or pale cream and in clusters. They grow on new wood. They are about 2
cm across.
Fruit are bell shaped and pale green, white, pink or red in colour. The flesh inside is mostly
white.
Growing watery rose apple
Trees grow well in the humid tropics on well-drained soil. They will grow up to about 1500
m altitude.
Trees are often grown from seed. They can occur wild in the forest where they are looked
after or they can be planted. They are easy to grow from cuttings and this method is often used.
Trees need to be 6-8 m apart if several are planted together.
Trees often flower and fruit twice a year.
Surinam cherry
Scientific name: Eugenia uniflora
What is the plant like?
The tree can be grown as a small bush and pruned into a hedge but if given space and good
soil can grow up to 7 metres tall.
The leaves are dark green and small (2-5 cm long). They are shiny and young leaves are a
red colour.
The flowers are small (1-2 cm across) and white. They are produced in the axil where the
leaf joins the stem.
Fruit are on long slender stems, bright red in colour and 2-3 cm across. The fruit have up to
8 ribs or indented lines around the fruit. Mostly there is one round seed inside. The skin of the fruit
is thin and the flesh juicy. The flesh is often red and is sour.
How do you grow Surinam cherry?
Mostly trees are grown from seed. Seeds grow within 3 to 5 weeks. Seeds should be
planted from freshly harvested fruit. If the seedlings are put in a nursery they should be
transplanted to where they will grow when they are 20 cm tall. Grafting of cuttings from better
trees can be used.
Trees can start to produce fruit after 3 years.
Trees can be pruned and trained into a hedge. Trees that are pruned often will produce less
fruit.
Where do trees grow?
This tree originally came from Brazil. It is tropical but will stand some cold once the trees
are growing well. It may grow up to 1700 m in Papua New Guinea but is not often seen above
about 800 m. It is better suited to wet than dry climates.
255
Rose apple
Scientific name: Syzygium jambos
What is the plant like?
This is a small tree up to 10 m tall.
The leaves are thick and shiny. They are long (22 cm) and sword shaped, or tapered at each
end.
The flowers are greenish white and large (8 cm). They are at the end of the small branches
or twigs.
Fruit are round (5 cm across) and white. At the top of the fruit the thickened parts of the
flower (calyx) form a flattened extended end to the fruit. The fruit has one or two seeds inside.
Growing rose apple
Trees can be grown from seed. Like many of the fruit trees in this family when a seed is
planted, several seedlings can grow from the one seed.
Flacourtia's or lovi lovi family
These fruit trees are a little difficult to separate into the four species. Four trees in the group
have become distributed around coastal areas of Papua New Guinea. They are:
Coffee plum
Flacourtia jangomas
Rukam
Flacourtia rukam
Lovilovi
Flacourtia inermis
Governor's plum
Flacourtia indica
Flacourtias are trees or erect shrubs that may or may not have spines on the trunk and
branches. Often wild forms have thorns and cultivated ones have no thorns. The leaves have short
stalks and are mostly toothed or wavy along the edge.
Some of the differences between them can be seen from this table.
Name
Tree
Leaf
Fruit
Flowers
Coffee plum
Small to 10 m
Deciduous
Fruit has a single peg
on top
Unisexual
Rukam
To 20 m tall.
Evergreen. Thorny
Small to 15 m
Evergreen. Thorns
Small to 15 m.
Deciduous. Often
thorny
Fruit with a circle of
4-7 pegs. Pink to red.
Fruit has cluster of 46 pegs. Bright red.
Fruit small (1 cm).
Fruit dark red
Unisexual. Separate
trees.
Bisexual.
Lovilovi
Governor's plum
3-6 prs of side veins
Blade 5-12 cm long
lLeaf blade pointed
5-10 prs side veins
Blade 7-20 cm long
5-10 prs side veins
Blade 7-20 cm long
Leaf blade blunt.
Blade 2-5cm long
Unisexual
These trees can be grown from seed, but they do not always breed true so that fruit may not
be as nice as that from the original tree. Because of this it is better to grow new trees by either
using air layering or budding. For lovilovis, seedlings take about 18 months to be large enough to
plant out. Trees need to be spaced about 14 m apart.
Flacourtia rukam
Flacourtia inermis
257
Mango
Several different species of mango trees grow in Papua New Guinea. The commonest one is
the main mango Mangifera indica but at least three wild species are also occasionally used for food.
These are Mangifera minor Bl.; Mangifera foetida Lour. and Mangifera altissima Blanco.
Mangifera minor has flowers that are shorter than the leaves.
The Mango Tree
The mango tree is a large evergreen tree up to 40 metres high with smooth leaves and a
rough brown bark. The dark green leaves are 12 to 30 cm long but like many tropical trees the
young leaves are flushed red. The flowers are small and occur in clusters at the ends of branches.
The flowers are pinkish white or yellow. Fruit are 5 to 20 cm long. The fruit often have long tough
fibres inside. The fruit have one large woolly stone inside.
Growing mangoes
Most of the mango trees in Papua New Guinea are seedling trees. Mangoes grow and
perform best in moderately dry coastal climates. They therefore do well near Rabaul, Port Moresby
and in the Markhum Valley. They will grow up to about 1900 metres altitude but only fruit poorly
in these areas. They grow best where the temperature is 24° to 27°C. Where trees are grown in
high rainfall places the trees grow well with lots of leaves but less fruit.
Normally mango seeds should be planted fresh but village people often dry and store seed
before planting. Mango seeds can produce several trees from one seed and these are trees which are
all the same in quality, like vegetatively produced trees. Several varieties of mango occur which
differ mainly in the shape and colour of the fruit. For the best trees it is important to use grafted
trees, as the fruit will be the same as the parent tree. These grafted trees tend to be lower with more
spreading branches. Because mangoes can produce several shoots from the one seed and some of
these are asexually produced, these can breed true to type.
The trees can be topped to produce a more spreading tree that means it is easier to harvest
the fruit. Trees will grow quite well on poorer types of soils. The sap of the tree can cause skin
rashes in some people. Trees begin to produce fruit after 4 or 5 years.
Fruit production is seasonal. The season is about November. Up to 400 or 600 fruit can be
produced by one tree. Flowers are pollinated by flies, and normally trees are cross pollinated
although some varieties can self pollinate. Fruit matures in about 2 to 4 months. Often trees
produce a large crop one year then a smaller crop the next year.
Pests and disease
Fruit flies are a problem with mango fruit especially where the fruit are left to ripen on the
tree. To help control these it is important to get rid of fallen ripe fruit.
Anthracnose is the name of a fungus disease that causes blossom blight, twig dieback and
fruit rot. This disease gets worse when there is a wet season and high humidity near flowering time.
Having trees well spaced and pruning out sections where branches and leaves are crowded together
helps control this a little.
Flowers and small fruit can also drop because of very cloudy days and because rainy
weather during flowering stops the pollinating insects and washes the pollen away.
259
Insect pests recorded on mango in Papua New Guinea
Aleurodicus dispersus Russel
Amblypelta spp.
Aspidiotus destructor Sign.
Bombotelia jocosatrix (Guen.)
Ceroplastes rubens Mask.
Chlumetia transversa Walker
Coccus viridis (Green)
Bactrocera bryoniae (Tryon.)
Bactrocera frauenfeldi Schiner
Dysmicoccus brevipes (Cockerell)
Helopeltis clavifer (Walker)
Idioscopus clypealis (Leth.)
Idioscopus niveosparsus (Leth.)
Ischnaspis longirostris (Sign.)
Noorda albizonalis Hamps
Protaetia fusca Herbst.
Rhyparida clypeata Jacoby
Saisettia coffeae Walker
Scopelodes dinawa B.Bak
Scopelodes nitens B.Bak
Selenothrips rubrocinctus (Giard)
Tip wilt bug
Aleyrodidae (HEM)
Coreidae (HEM)
Diaspididae (HEM)
Noctuidae (LEP)
Coccidae (HEM)
Noctuidae (LEP)
Coccidae (HEM)
Tephritidae (DIPT)
Tephritidae (DIPT)
Pseudococcidae (HEM)
Miridae (HEM)
Cicadellidae (HEM)
Cicadellidae (HEM)
Diaspididae (HEM)
Pyralidae (LEP)
Scarabaeidae (COL)
Chrysomelidae (COL)
Coccidae (HEM)
Limacocidae (LEP)
Limacocidae (LEP)
Thripidae (THYS)
Large mango tip borer
Spiralling whitefly
Tip wilt bugs
Coconut scale
Large mango tip borer
Pink wax scale
Mango shoot caterpillar
Green scale
Fruit fly
Fruit fly
Pineapple mealy bug
Cacao mirid
Mango hopper
Mango hopper
Armoured scale
Red banded mango borer
Mango flower beetle
Brown coffee scale
Cup moth
Cup moth
Cacao thrips
Moth of mango shoot caterpillar
Mango hopper
Cacao mirid
Cacao thrips
Mango flower beetle
Cup moth
Cup moth pupa
Mango diseases
Sooty mould
Pink disease
Leaf spot (Anthracnose)
Asterina sp
Meliola mangiferae
Phanerochaete salmonicolor
Glomerella cingulata
Stigmina mangiferae)
Fungi
and
Fungus
Fungus
(and possibly
Food value
The fruit are eaten fresh but can also be used for jam or juices. The young leaves can be
cooked and eaten. The seed can also be eaten.
The food value of 100 g of the edible portion:
Moisture
Energy
Protein
%
cals
g
Fruit
82.6
62
0.6
Leaves
3-4
Calcium
mg
10
Iron
mg
0.3
provitA
!g
1880
Some mangoes have a turpentine flavour and others are more fibrous.
elongated kinds are often the best.
provitC
mg
36
Some of the
Marita
Tok Pisin: Marita
Scientific name: Pandanus conoideus
The marita pandanus plant
This pandanus is a short tree with several branches. Near the base it has several prop roots
that help hold the plant up.
The leaves are between 1 and 2 metres long and about 10 cm wide. There are thorns along
the edges of the leaf.
Trees may have up to 8 or 10 main branches. Trees grow up to about 5 metres tall. There
are spikes on the trunk and branches.
The fruit are long (30 to 60 cm) and mostly red although yellow kinds occur. The fruit is
hard and has small lumps or spikes over the surface. The fruit grows at the ends of the branches
between the leaves and it has 3 straight leaf-like bracts along the edges.
The leaves grow opposite each other but are twisted to look like a spiral.
261
Where is marita grown?
Marita is grown throughout Papua New Guinea from sea level up to about 1650 metres
altitude above sea level.
It is only grown in Papua New Guinea.
In these areas, people often plant marita along the roads and walking tracks. It is also
planted in most gardens and serves as a reminder that the land is owned, by the person who planted
the marita. So, often marita plants belonging to one person are scattered in lots of different places.
How do you plant marita?
Marita pandanus is normally planted from suckers or cuttings. The end of a branch can be
cut off and used as a cutting. A new shoot normally sprouts out of the branch just below where the
end was cut off. The cutting will soon develop roots and become established when it is planted.
A more popular method is to use a sucker or shoot growing from the plant down near the
ground. The sucker is separated from the parent plant then replanted in its new place. These
suckers grow more quickly and can bear fruit after 18 months to 2 years. A cutting off a branch
may take up to 4 or 5 years before it produces a fruit.
How is marita used?
A marita fruit is harvested when the colour starts to change to a brighter red or yellow.
Sometimes it also starts to crack slightly at this stage. The fruit is cut from the branch.
Marita fruit
A ripe marita fruit is normally split into 3 sections along its length. Traditionally this was
often done with a knife made from the sharpened leg bone of a cassowary.
Fruit
split
open
Then the central yellow stalk and pith area are dug out. The outside hard red layer is then
cooked. Preferably it is cooked using hot stones although sometimes it is boiled in a saucepan.
After cooking for about half an hour the hard pits are squeezed from the soft red juice by squeezing
through the hands. Water is added to make an oily red soup.
Squeezing marita with water.
The soup is then eaten. Sometimes it is eaten, by dipping green leaves or sago into the
soup. At other times it is eaten with a spoon made from the marita leaf. Some people just suck the
cooked juice from the seeds. As well, some people use the oily juice to cook food in.
The pits or seeds are thrown away, normally to pigs.
263
A harvested marita fruit will only keep for about one week. After cooking it will only last
for about 12 hours.
When is the marita season?
Marita is a seasonal crop but the fruiting season is not a short clearly marked one. The main
season goes from about October to March but individual trees can bear almost throughout the year.
Near the sea the marita season is longer and more spread out but as the places increase in altitude
above sea level the season becomes more distinct. The marita season is an important occasion.
During the season people often use marita twice a day.
Diseases, insects and other pests
Some diseases can fairly often be seen on the leaves of marita pandanus. Two fungi are
common. One causes a black leaf mould that grows in a line along the leaf. The other one causes a
brown dead spot that has a yellow ring around it. It is not known how much damage these diseases
cause.
Black leaf mould
Leaf spot
In marita areas fruit which still aren't ripe sometimes "stink nating" going soft and squashy.
They are mostly just cut off the tree and left to rot. The cause is not known.
The larvae of an insect can often be seen eating marita leaves. If it eats the growing point it
can kill the branch or the tree. This insect can get so bad that a poor marita season results.
In some areas tree kangaroos can also do serious damage to fruiting marita.
The food value of marita
Not very much is known about the food value of marita. Often the red colour in plants is a
chemical called carotene that produces vitamin A. In marita the red colour is not carotene. Marita
appears to have a fairly high oil content.
Mon
Scientific name: Dracontomelon dao
What is Mon?
Mon is the Tok Pisin name of a common coastal tree that has edible fruit. Scientists have
given it the Latin name Dracontomelon dao. This name was first given to the tree in 1908. Other
scientific names were originally given. Two other names still sometimes used are Dracontomelon
mangiferum and Dracontomelon puberulum. They all refer to the same plant.
What is Mon like?
It is a large forest tree with large buttresses at the base. The tree is in the mango family and
has leaves made up of about 6 to 10 pairs of leaflets along a stalk. The flowers are small and grow
as a group of small flowers at the ends of branches. They are pale yellow and about 1 cm wide.
The fruit are round, 3 or 4 centimetres across and have a small amount of edible flesh
around a large seed. The fruit turn yellow when ripe. The fruit have 5 small scale-like flakes
around the middle.
265
The wood of the Mon tree is pale brown with black stripes and is sold as a timber called
New Guinea walnut.
Where does Mon grow?
Mon trees are tropical trees and grow in several Asian countries including Papua New
Guinea. Countries that have Mon include Thailand, India, China, Cambodia, Malaysia, Indonesia,
Philippines, Papua New Guinea and the Solomon Islands.
The tree only grows properly in high rainfall areas and is mostly in coastal areas but
sometimes up to 500 or 1000 metres altitude.
Trees are more common along rivers and are also planted in villages.
In Papua New Guinea, Mon trees are particularly popular as fruits in the Madang Province.
Trees in the bush inland often have smaller fruit that are more sour. Fruit near the coast are larger
and sweeter.
How do you grow Mon fruit?
Mon trees often grow naturally in the lowland bush. But in areas where mon are popular,
and where sweeter kinds of mon occur, trees are planted. They are grown by using the seed out of
the centre of a fruit.
If the tree is well looked after and well grown, it can start producing fruit after 3-4 years.
Using Mon fruit.
Mon fruit are produced seasonally. The season normally coincides with the breadfruit and
mango season. The fruit turn slightly yellow when ripe and the seed inside turns brown. If the seed
inside is white, then the fruit is not ripe.
Mulberry
Names: White mulberry
Black mulberry
Scientific name: Morus alba
and Morus nigra
The plant
These are small trees that grow up to about 9 metres high. They lose their leaves during the
year. The leaves are oval and toothed around the edge. The fruit is dark red to black in colour.
Mulberries leaves are often used for silkworms.
Trees often bear fruit twice a year. The trees will live for many years.
Growing mulberries
They need a fertile and well-drained soil but can grow in acid soils. They are grown mainly
between 700 m and 2400 metres altitude.
The tree grows easily from cuttings but can also grow from seed that often fall and grow
naturally. When cuttings are used a piece of the current season's growth should be used. It should
be about 30 cm long and preferably with a heel of two-year old wood.
If the growing point of the tree is pinched out it causes the tree to spread out more and this
makes it easier to harvest. Because trees "bleed" or lose sap easily it is best not to do too much
pruning.
267
Mulberry insect pests
Tiracola plagiata Walk
Maconellicoccus hirsutus (Green)
Lagria sp.
Rhyparida coriacea Jac.
Howardia biclavis (Comstock)
Icerya seychellarum (Westwood)
Parasaissetia nigra (Nietner)
Planococcus pacificus Cox
Noctuidae (LEP)
Pseudococcidae (HEM)
Chrysomelidae (COL)
Chrysomelidae (COL)
Diaspididae (HEM)
Margarodidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Cacao armyworm
Hibiscus mealy bug
Shot hole damage to leaves
Feeding on leaves.
Nigra scale
A spray of white oil and malathion could be used for scale insects but because people eat
mulberry leaves it is a dangerous practice to spray. Normally scale insects can be controlled by
ladybird insects.
Mulberry diseases
Leaf spot
Fungus
Phyllosticta sp.
The fruit are eaten raw. Mulberry fruit leave a dark purple stain. If some unripe berries are
rubbed over the stain it can be removed.
The leaves are edible cooked.
Mundroi
Scientific name: Corynocarpus cribbianus
What is Mundroi?
Mundroi is the name used on Manus Island for the fruit of a tree that scientists call
Corynocarpus cribbianus. The first botanist to describe the tree was F.M.Bailey in Queensland in
1897, but the name was changed a couple of times until in 1956 Corynocarpus cribbianus was
decided as the correct scientific name.
There are only 4 species of trees in this group of plants called Corynocarpus. And the group
is not closely similar to other plants so scientists are still trying to work out how it is related to other
groups of plants. One of the other species, Corynocarpus laevigata, is called karaka in New
Zealand, and the flesh of the fruit is eaten raw, and the kernel is soaked and steamed to remove
poison, then eaten, by Maori people.
The group of plants called Corynocarpus only occur in an area between New Zealand and
New Guinea, including a little bit of Queensland in Northern Australia.
What is a Mundroi like?
The mundroi tree is quite a large tree up to 20 metres high. The fruit are produced in
clusters at the ends of the branches and are shaped something like a mango. The fruit are smooth
on the outside and green when ripe. There are two different kinds of fruit that vary on the colour of
the ripe fruit. One kind turns a reddish pink when ripe while the other kind turns a creamy white.
This second kind has the larger fruit.
269
The fruit grows up to 10 or 12 cm long and 6-8 cm across. Inside there is one large seed, and
the flesh around the seed is eaten.
The fruit is only eaten when fully ripe and it is harvested after it has fallen from the tree.
The fruit is eaten either raw or cooked. The flesh of the fruit is sweet but not juicy.
The mundroi tree has leaves that are dark green on top and pale green underneath. They
have veins that join in loops. The veins are raised on the underneath side of the leaf.
Mundroi trees are normally planted. They are grown from seed. The similar karaka tree in
New Zealand will grow from cuttings, so it would be worth trying this with mundroi.
The flowers have a sweet smell and the petals are white with slightly red tips.
Naranjilla
Tok Pisin: temeta?
Scientific name: Solanum quitoense
The naranjilla plant
This plant is a small shrub that grows about 1 or 2 metres high. It has fine hairs over it and
also thorns.
The leaves are large and green with small brown hairs on them.
The fruit are round and about 5 cm across. They are covered with white hairs which can
easily be rubbed off. These fruit are produced in groups along the stem and branches of the shrub.
The fruit are an orange colour on the outside and the flesh inside is green.
How is it used?
The fruit have a slightly acid taste. They are mostly used for drinks and sweet dessert
dishes.
How is it grown?
Inside the fruit there are lots of seeds. These can be sown to produce new plants.
The plant can also be grown from cuttings. The cuttings need to be about 15 cm long.
When the cuttings have been collected they should be dried for a few days to let the cut surface
heal. This stops the cuttings from rotting when they are planted. They can then be planted in moist
soil.
271
Where is it grown?
The naranjilla is a South American plant.
It is grown in some of the highland areas of Papua New Guinea.
It is grown around the Eastern Highlands and in the Southern highlands it is grown in the
Pangia district near Mele village. The people there know and use it. It has probably only recently
been introduced.
It grows best in the medium altitude areas of the tropics. In other countries it grows
between 800 and 2000 metres above sea level.
Pests and diseases
In Papua New Guinea these haven't yet been looked at. As the plant is in the tomato and
potato family it will probably suffer from root knot nematode and bacterial wilt.
Tree tomato
(Also called tamarillo)
Scientific name: Cyphomandra betacea
This is a small fruit tree or shrub in the tomato and tobacco family. People often use the
same Tok Pisin name as for tobacco because they understand this fruit is related to tobacco.
The shrub grows up to about 4 metres high and has soft wood. It only lives for a short time
of about 4 or 6 years. Trees need to be about 3 m apart. The leaves are more or less heart shaped
and softly hairy.
The fruit are about 6 cm long and acidic. They have a pointed end. They can be red, orange
or purple in colour. They are produced after about one year. The flesh of the fruit is light orange
with black seeds.
It occurs fairly commonly in the highlands between 750 and 2300 metres altitude. It is
slightly more hardy to cold temperatures than the tomato. They do best where average temperatures
are about 15° - 21 °C.
Growing tree tomatoes
The trees can be grown in shade as well as in full sunlight. They need fertile soil. The
plants cannot stand waterlogging or drought.
Trees can be grown from seed or cuttings. The cuttings produce a lower bushier type of
plant. Cuttings of 60 to 90 cm long stalks are suitable. Because the roots are easily damaged by
nematodes, plants grafted onto rootstocks that are resistant to nematode will live longer.
273
The plant is shallow rooting and therefore needs to be weeded carefully so that the roots are
not damaged. You should not use a hoe when weeding.
Tree tomato diseases
Leaf spot
Spots (Anthracnose)
Root rot
Ascochyta sp.
Glomerella cingulata
Phytophthora palmivora
Pythium sp.
Meloidogyne sp.
Fungus
Fungus
Fungus
and
Nematode
Root knot
The root rot fungus can mean it is difficult to get plants established in old gardens. The root
knot nematodes also mean trees can die more quickly than they should, and sometimes in 3 or 4
years.
Insects.
At least one fruit fly damages the fruit of tree tomato.
Dacus tryoni Frogg
Tephritidae (DIPT)
Queensland fruit fly
Tree tomato fruit as food
The fruit can be eaten raw or cooked.
The food value of 100 g of the edible portion is:
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
86.2
113
2.0
500
28
0.7
Zinc
mg
Passionfruits
Several passionfruit plants are used for their edible fruits in Papua New Guinea. These include:
Passiflora edulis
Passiflora foetida
Passiflora laurifolia
Passiflora edulis v flavicarpa ligularis
Passiflora mollissima
Passiflora tripartita var. quadrangularis
Yellow passionfruit
Granadilla
Purple passionfruit
Passionflower
Yellow granadilla
Yellow passionfruit
Banana passionfruit
Granadilla
Purple passionfruit
Passionflower
Banana passionfruit
Yellow granadilla
275
Purple passionfruit
This passionfruit has been introduced to several areas of the highlands to grow for sale of
the fruit for juice. It is now fairly common in villages. It suits alternate wet and dry season
climates and probably grows best at about 1000 metres altitude. It grows up to 3,000 metres
altitude. It can only withstand very light frosts. There is a yellow variety that is grown at lower
altitudes. (There is also a different species with yellow fruit but which has larger entire leaves.)
The plant is a semi woody vine with tendrils that help it cling onto a fence or trellis. Once
established, the plant will keep growing for several years. The leaves are deeply three lobed and
toothed along the edge. The flowers smell sweetly and are about 4.5 cm across. They are borne
singly near the leaves along new shoots. The flowers are very attractive. The fruit has a brittle
outside shell and inside are many small seeds, surrounded by a yellow juicy pulp. The fruit is 4-6
cm long. Often several vines are needed near each other to allow the pollen to spread between
plants and enable fruit to develop. Bees and other insects help pollinate the plants. Plants can be
pollinated by hand by taken the pollen from the flower on one plant and putting it on the flower on
another plant. This needs to be done during the morning.
It can be grown from seed or by layering where the vine is put under the ground until roots
develop then this section is cut off and replanted. The seed do not germinate quickly (2 weeks to 3
months) but are fairly easy to grow. It can also be grown from cuttings of mature wood. The
cuttings should be about 15 cm long that have 2 or 3 nodes and are from vines about the thickness
of a pencil. The vines are normally grown over a trellis or along a fence or over a house. The first
main crop is produced 18 months after planting.
The fruit turns purple, wrinkles then falls off when ripe.
The fresh fruit can be eaten, by simply cutting the fruit in half, and eating the soft contents
in the centre.
Purple passionfruit
Yellow passionfruit
Yellow passionfruit. Although there is a yellow variety of the purple passionfruit, this
species has leaves that are large (10-20 cm across) and flowers that are 7-10 cm across. The fruits
are also larger being 7-10 cm across.
Banana passionfruit has become a wild plant in the high altitude areas and at areas above
2400 metres can often be seen growing extensively over the forest trees. The long yellow fruit are
particularly picked and eaten by children.
Granadilla. This plant has distinct four angled stems. It grows in the lowlands and suits
warm moist climates. It has large green tendrils that cling onto fences. The flower is large (10 cm
across) and with purple threads. The fruit are large (30 cm x 15 cm) and green but turn slightly
yellow when ripe. The flesh is white and juicy with many seeds. The seeds are flattened and dark
brown and about 1 cm long.
It can be grown from seeds of cuttings. This plant often sets better fruit if it is hand
pollinated.
Banana passionfruit
Granadilla
Granadilla
277
Yellow granadilla. The leaves of this one do not have lobes and they are rounded (10 cm x
5 cm) hairless and rough. The flowers are large (6 cm across). The fruit are oblong and taper at
both ends. They are about 8 cm x 5 cm and smooth and yellow when ripe. This one is less
common. The fruits are eaten raw.
Passionflower is a common weed and
children eat the small round yellow berries. It has
been used as a cover crop in plantations.
Diseases passionfruit family
Banana passionfruit
Fruit spots
Fungus
Colletotrichum sp.
Stem death
Chlorotic spot
Fungus
Virus
Glomerella cingulata
Chlorotic spot virus
Brown leaf spot
Seedling wilt
Blight of flowers
Fruit rot
Root knot
Fungus
Fungus
Fungus
Fungus
Nematode
Alternaria passiflorae
Phytophthora nicotianae
Aspergillus sp.
Fusarium sp.
Meloidogyne javanica
Granadilla
Passionfruit
Brown spot fungus Alternaria passiflorae causes the leaves to turn brown and to drop off. It
gets worse where plants are planted close together. This disease can also get on the vines and can
cause the end of the vine to die off. On the fruit sunken brown spots can occur when the disease
gets on fruit. Pruning out some of the very thick vine growth helps control the disease. It could be
sprayed with fungicide if this were appropriate.
Insect pests of passionfruit
Helopeltis clavifer (Walker)
Hemiberlesia lataniae (Signoret)
Hemiberlesia palmae (Cockerell)
Idopsis grisea Faust.
Leptoglossus australis (Fab.)
Oribius cinereus Mshl.
Planococcus citri (Risso)
Pseudaulacaspis pentagona (Targioni)
Planococcus pacificus Cox
Tiracola plagiata Walk
Coreidae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Curculionidae (COL)
Coreidae (HEM)
Curculionidae (COL)
Pseudococcidae (HEM)
Diaspididae (HEM)
Pseudococcidae (HEM)
Noctuidae (LEP)
Cacao mirid
Black leaf-footed bug
Shot hole weevils
Citrus mealy bug
White scale
Cacao armyworm
Food value 100 g edible portion
Common name
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
Edible part
Purple passionfruit
Passionflower
Passionflower
Yellow granadilla
Sweet granadilla
Granadilla
Granadilla
Banana passionfruit
73.3
64.2
86.0
280
421
176
2.8
4.9
6.9
10
20
5
220
1.3
8.4
0.1
1.1
78.5
78.4
94.4
393
339
170
2.8
1.9
0.7
20
20
15
15
0.9
2.9
0.8
Fruit
Fruit
Leaves
Fruit
Fruit
Seed & aril
Flesh only
Fruit
Pawpaw
Scientific name: Carica papaya
The Plant
Pawpaw is one of the very well known fruits of Papua New Guinea. The straight-stemmed
plant grows up to 3-5 metres tall and only occasionally has branches. The stem is softly woody and
has scars from fallen leaves along it. At the top of the plant there are a clump of leaves. The leaves
are large (50 cm wide) deeply lobed and on long leaf stalks.
Several kinds of fruit occur. They are normally oblong or round, and yellow. The breeding
behaviour of fruit will be explained in a few moments. The fruit mostly have many seeds inside.
(There can be 300-700 seeds). Most of the fruit in Papua New Guinea has yellow flesh but redfleshed kinds can occur. Yellow flesh colour will replace red flesh colour where both occur in the
same group of interbreeding plants. So plants will soon produce yellow fruit.
Fruit shape
Trees of pawpaws can be of two separate sexes or they can have both sexes on the one tree.
Then for the ones with both sexes on the one tree there are several different fruit shapes.
Male trees have flowers on long stalks and mostly don't produce any fruit although they
sometimes fruit if the top is chopped off the plant.
279
male flower and no fruit
Female trees only have female flower parts and when these are pollinated from a male tree
will produce round fruit. But seeds saved from these fruit will come up half male trees and half
female trees.
female flower and round fruit
Other trees with both male and female flower parts produce long fruit. Whether the fruit is
smooth around the fruit or has ridges or is twisted and what sort of plants grow when the seed is
planted, depends on where the pollen comes from.
bisexual flower and long fruit
If people just want fruit to eat in their gardens or in the villages and they are not very fussy
about the shape of the fruit, then the simplest rule is to just chop down all male trees and gradually
develop all long fruited types. As these trees have both male and female parts they can fruit without
male trees. And without male trees present, the seed that is saved and planted will all produce trees
that have fruit.
fruit shapes long –twisted, ridged, smooth
Red fruited selection
This chart shows how the breeding behaviour occurs.
Parents
Offspring
Female
Male
Female x male
1
1
Female x long bisexual
1
0
Long bisexual x male
1
1
Long bisexual self fertilised
1
0
Bisexual
0
1
0
2
To avoid male plants that don't bear fruit, pollen must come from bisexual fruit. Some of
these types can also be influenced by the environment at the time the flower buds form.
Mountain pawpaw.
In the highlands of Papua New Guinea another pawpaw plant has been introduced. It grows
from 1650 m altitude up to about 2200 m. It can stand a light frost. The fruit are small. The
scientific name of the plant is Carica candamarcensis.
Growing pawpaws
In the lowland rainforest pawpaws just come up naturally when the forest is cleared. The
sunlight allows the seeds that have been scattered by birds and flying foxes to start growing. So in
the lowland forest areas people rarely plant pawpaws. As they are clearing the forest they look after
female or bisexual trees and chop down male trees. Sometimes people just casually plant trees by
scattering pawpaw seeds from the fruit they are eating. Pawpaw seeds grow easily and plants grow
quickly. Fresh seeds can be used or if dry seeds are used they should be soaked before planting. To
produce well they need a reasonably fertile soil.
Pawpaws will grow from sea level up to about 1700 m altitude. In the highlands they have
to be planted. Seeds can be sown directly or the seeds can be put in a nursery and the seedlings
transplanted. Seeds in a nursery should be about 1-2 cm deep. Seedlings can be transplanted when
they are about 20 cm high. Plants should be about 3 m apart. On the coast pawpaws start
producing fruit after about 4 or 5 months but in the highlands this may not start for 12-18 months.
With good growth 100 fruit can be produced from one plant in a year.
Using pawpaws
Mostly in Papua New Guinea fruit are just eaten ripe as a snack. They can be eaten green
by being cooked like a vegetable by boiling.
Food value in 100 g edible portion:
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
Edible portion
88.0
75.4
163
378
0.5
8.0
290
54
140
0.4
0.77
0.18
Fruit
Leaves
281
Pest and disease
Diseases of pawpaw
Disease
Butt rot
Leaf spot
Shot hole leaf spot
Leaf spot (Anthracnose)
Powdery mildew
Leaf spot
Root rot
Leaf spot & fruit rot
Fruit rot
Fruit rot
Stem rot
Mosaic
Root knot
Cause
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Bacteria
Virus
Nematode
and
Scientific name
Athelia rolfsii
Cercospora papayae
Corynespora cassiicola
Glomerella cingulata
Oidium caricae
Phyllosticta sp.
Phytophthora palmivora
Mycosphaerella caricae
Botrydiplodia theobromae
Fusarium oxysporum
Pseudomonas cepacia
Meloidogyne incognita
Meloidogyne javanica
Leaf spot & fruit rot pawpaw is caused by a fungus Mycosphaerella caricae of which the asexual form is Phoma
caricae-papayae. This fungus produces a black spot on mature fruit and brown and white spots on leaves. Leaf stalks
and stems can also be affected. The fruit rot gets worse in rainy seasons. Although rain is not essential for the disease
to spread it gets worse with rain showers or in high humidity. The fungus blows in the wind. Leaf stalks may rot,
young stems may rot at the end and plants can actually die back. Flowers may fall off and young fruits die. Fruit may
continue to rot after harvest. To help control it, remove and burn infected plant material. Fungicide sprays can be used.
Fruit after harvest can be put in hot water at 33°C - 33°C for 20 minutes to stop infected fruit rotting. The disease is
described in CMI Descriptions of Pathogenic Fungi No 984
The fungus Cercospora papayae is also recorded from Papua New Guinea and probably does similar damage.
Mosaic of pawpaw is probably caused by a virus. Young leaves turn yellow and do not grow properly. Often there are
yellow patches around the edge of the leaf. Trees are stunted. Often they grow several side branches. Affected trees
are of little use. The disease is described in Vock,N.T., 1978, A Handbook of Plant Diseases in Colour. Vol 1
Queensland DPI
Powdery mildew of pawpaw is caused by a fungus Oidium sp. Light yellow patches develop on the young leaves.
These become soft and water-soaked and have a white powdery growth over them. Round white patches can also
develop on the fruit. Grey scarred areas are left after the white mould disappears. The disease spreads with the fungal
spores blowing in the wind and rain. It is mainly a disease of seedlings that are planted too close together. Control is
by using wider spacing in nurseries. Seedlings can be treated with a sulphur fungicide. (Sulphur dust can be used but
can damage leaves when the temperature in above 24°C).
Root rot of pawpaw is caused by a fungus Phytophthora palmivora. Often Pythium sp. fungi are also involved. The
older leaves turn yellow and collapse hanging limply around the trunk. The young leaves then die and the plant dies.
Large roots show a soft wet decay and small roots are missing. Fruit can also be affected by this fungus. It occurs in
warm areas with a high rainfall. Spores of the fungus can spread by wind and rain. They can be in the soil. Plants
especially in wet areas die. A large number of plants can be damaged by this fungus eg pawpaw, coconut (bud rot),
tomato, oil palm, rubber, cacao (black pod) etc. For control, avoid wet areas and do not replant pawpaws into soil
where the disease is known to occur. Plant only disease free trees from a nursery that has clean soil. Avoiding damage
to pawpaw trunks reduces trunk rot. The disease is described in the CMI Descriptions of Pathogenic Fungi No 831 and
in Holliday, 1980, Fungus Diseases of Tropical Crops CUP.
Shothole of pawpaw is also called Brown spot and is caused by a fungus Corynespora cassiicola. Light-brown, round
spots about 1 cm across develop on pawpaw leaves. The centre can sometimes fall out of the spots. Spots can also
appear on petioles and fruit. The disease gets worse with temperatures between 20°C and 27°C. It can be carried on
seed or can live on old diseased plant parts for up to 2 years. The spores can blow in the wind. On pawpaw, the disease
is not serious. The same fungus also gets on tomatoes, eggplant, watermelon, melon, banana, daka, castor oil plant,
soya bean, cowpea and some flowering plants. It has been recorded causing a leaf spot on sweet potato. Control is not
normally required for pawpaw. The disease is described in the CMI Descriptions of Pathogenic Fungi No 303 and in
Holliday, P., 1980, Fungal Diseases of Tropical Crops. Cambridge p 114.
Other leaf spots due to a Phyllosticta sp. fungus probably also cause similar spots with a hole in the centre.
Pawpaw insect pests
Boring stems
Cane weevil borer
Weevil reported damaging pawpaw
Reported rotting fruit and dying petiole scars
Rhabdoscelus obscurus Boisduval
Rhinoscapha maclayi MacLeay
Araecerus sp. (See Oxyderes )
Oxyderes cyrtus Jordan
Curculionidae (COL)
Ischiopsopha bifasciata Quoy & Gaim var.
hyla Heller
Cetoniinae (COL)
Tiracola plagiata Walk
Adoxophyes melichron
Noctuidae (LEP)
Tortricidae (LEP)
Amblypelta spp.
Coreidae (HEM)
Aspidiotus destructor Sign.
Pseudaulacaspis pentagona (Targ.)
Drepanococcus chiton (Green)
Aonidiella orientalis (Newstead)
Aspidiotus excisus Green
Chrysomphalus dictyospermi (Morgan)
Howardia biclavis (Comstock)
Morganella longispina (Morgan)
Pseudaulacaspis cockerelli (Cooley)
Pseudaulacaspis pentagona (Targioni)
Icerya seychellarum (Westwood)
Steatococcus samaraius Morrison
Coccus hesperidium Linnaeus
Coccus longulus (Douglas)
Saissetia coffeae (Walker)
Diaspididae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Anthribidae (COL)
Anthribidae (COL)
Damaging fruit
Reported adults feeding on ripe pawpaw fruit
Eating leaves
Cacao armyworm
Leaf roller
Sucking sap
Amblypelta bugs
Scales
Coconut scale
White scale
Armoured scale
Armoured scale
Armoured scale
Armoured scale
Armoured scale
Soft scale
White scale
Soft brown scale
Soft scale
Coffee scale
Mealy bugs
Dysmicoccus nesophilus Williams
Ferrisia virgata (Cockerell)
Aphids
Potato aphid
Macrosiphum euphorbiae (Thomas)
Aphididae (HEM)
Bactrocera musae (Try.) &
Bactrocera bryoniae (Try.)
Bactrocera neohumeralis Hardy
Tephritidae(DIPT)
Fruit fly
Banana fruit fly
Fruit fly
Leaf spot
Tephritidae (DIPT)
Virus
283
Pineapple
Scientific name: Ananas comosus
The pineapple plant
Pineapples are small cactus like plants up to 1 metre high and with thick fleshy leaves. The
leaves are arranged in spirals. Some kinds have thorns along the edges of the leaves. The plant
produces suckers both near the base of the stem and also higher up the stem near the fruit. These
are called slips and they with the suckers are broken off and used for planting. The main plant dies
after producing a fruit but the suckers keep growing.
The pineapple fruit grows at the top of the plant or the top of the branches.
The two main kinds of pineapples are the rough leafed variety that has spines on the leaves
and produces a smaller but sweeter fruit. The other kind is the smooth leaf kind with spineless
leaves and larger fruit.
Growing pineapples
The suckers and slips can be used for planting as well as the top of the fruit. The time to
maturity is the fastest for the suckers near the bottom of the plant and slowest when the top of the
fruit is planted.
Pineapples need well-drained and fertile soil. They suit an acid soil and can develop rots in
soils where lime has been added. The soil acidity can be between pH 3.3 and 6.0. The best range is
pH 4.5 to 5.5. They can grow in partial shade and in this situation the plants are normally more
green. The red colouring of pineapple leaves is due to a deficiency of the nutrient nitrogen. This
shows up more quickly in plants in full sunlight.
Pineapples can be planted with 35,000 to 43,000 plants per hectare or 3 or 4 plants per
square metre. If plants are spaced more widely they produce more suckers. Fruits become more
acid where plants are closely spaced. If too many suckers are left growing from the main plant then
smaller fruit will be produced.
The growth rate for pineapples gets slower as the temperature gets less. So plants grown in
the highlands take longer to get ready for harvest. It takes 60 days from when the flower starts to
form until it appears. Then there are 5 months until the fruit is ready for harvest. The time from
planting to harvesting ranges from 11 months up to 32 months depending on temperature. The fruit
are smaller, poorer shape and more acid where the temperatures are lower or there is less sunlight.
When the plant is sufficiently large it responds to changes such as less nutrients available or
less water available and starts to produce a flower then a fruit. The number of hours of sunlight as
well as reducing temperature and reduced sunlight also help the flowers start to form. The result of
this is that flowering and fruiting is often seasonal. This can easily be changed by using a fruiting
hormone that allows fruit to be produced at times to suit the grower.
Where are pineapples grown
Pineapples need an annual average temperature between 17.2°C and 26.9°C. In Papua New
Guinea this is mostly between sea level and 1800 metres altitude.
Pineapples can grow in semi arid conditions and this is because the leaves can store some
water. They also tend to lose only small amounts of water evaporating through their leaves. But
with plenty of water they can grow well.
The roots are very sensitive to waterlogging. Therefore the soil must be well drained.
Pineapples do not cover the soil well so it is good to use a mulch of plant material to help weed
control, provide some nutrients and to stop soil erosion.
Red colour due to nitrogen
deficiency
285
Using pineapple fruiting hormone
Because pineapples fruit at a couple of main seasons, especially in the lowlands this means
that at some times there are lots of pineapples and at other times they are unavailable. There is a
chemical available that can be poured onto the plant and this will help fruit to form at any time of
the year. The chemical is called pineapple fruiting hormone or phyomone. When the plant is
sufficiently well grown a solution is made up and applied to the plant. Fifty drops of hormone in
half a bucket of water (4.5 litres) for 75 plants or four drops in a fish tin of water for 7 plants, is
mixed up. Then a little of this is poured into the top heart of the plant. A flower and fruit will then
start forming. This needs to be done to different plants each few weeks if a regular supply of
pineapples is required. After the hormone is applied it takes about 20 to 24 weeks for fruit for
rough leaf pineapples and 26-30 weeks for smooth leaf pineapples.
Pests and diseases
Diseases
Water blister
Leaf blotch
Leaf spot
Wilt outside leaves
Cerotocystis paradoxa
Cochliobolus lunatus
Stachylidium bicolor
Trichobotrys pannosa
Asterina sp.
Nigrospora sp.
Pythium vexans
Fungus
Fungi
and
and
Fungus
and
Fungus
Water blister of pineapple is also called Base rot of pineapple is due to a fungus called
Ceratocystis paradoxa. Yellowish white leaf spots develop on the leaves. Suckers can develop a
base rot. Fruit can rot. The diseased parts are soft and watery and have a smell. The disease gets
worst at temperatures of 15°-21°C. It also gets worse with moisture and shade. It normally gets
started where the plant is damaged. The fungus is very common in soil. It gets into plants through
wounds. Spores can be spread by wind and rain. Fruit rot. Plants can die. Sugarcane, coconut,
bananas, betel nut, coffee, cacao, and maize can also be attacked by this fungus. For control use dry
healthy suckers and cure slips before planting. Don't plant pineapples and sugarcane together, get
rid of diseased plant parts, don't damage plants, leave a stalk on fruit that is cut, plant during dry
sunny weather, dry off tops and butts before planting and plant pineapples on mounds or well
drained soil.
Pineapple insect pests
Coccus viridus (Green)
Dysmicoccus brevipes (Cockerell)
Kilifia acuminata (Signoret)
Leptococcus metroxyli Reyne
Locusta migratoria (Linnaeus)
Maconellicoccus hirsutus (Green)
Planococcus pacificus Cox
Pseudococcus longispinus (Targioni)
Pulvinaria ubicola (Cockerell)
Scapanes australis grossepunctatus Sternb
Scapanes australis australis (Boisd.)
Coccidae (HEM)
Pseudococcidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Acrididae (ORTH)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Coccidae (HEM)
Dynastidae (COL)
Dynastidae (COL)
Soft scale
Pineapple mealy bug
Soft scale
Mealy bug
Migratory locust
Hibiscus mealy bug
Mealy bug
Mealy bug
Soft scale
N G Rhinoceros beetle
New Guinea Rhinoceros beetle
The mealy bugs can be controlled to some extent by dipping the planting material in a
chemical called malathion. All chemicals have to be treated very carefully and stored very safely
but malathion is one of the safer ones to use.
Sugarcane
Scientific name: Saccharum officinarum
Sugarcane
Most scientists consider that Papua New Guinea is the original home of sugarcane. It is one
of the major centres in the world for sugarcane varieties. Several hundred varieties have been
collected and used as the basis for the sugarcane crops in most countries of the world.
Sugarcane in subsistence is one of the commonest and most widely used of the food plants
of Papua New Guinea.
The preferred varieties for chewing are normally very tall growing (up to 5 m) and thick (56 cm across). These large canes are also important in ceremonial exchanges.
Drawing by Celia Bridle
The plant
This coarse erect grass is a rapidly growing clump forming grass. The leaves clasp the stem
then bend out with leaf blades up to 1.3 m long and 10 cm wide. At the top in many varieties a
large open flower is produced.
A very large number of varieties occur. These not only vary in their height and thickness,
but also in colour, length of internodes, toughness of the stem and in many other ways. Many of the
stripes and colour patterns on the stems are just surface changes and sometimes not really good
guides to how different the canes really are.
287
There are also important variations between varieties in how effectively they convert
sunlight to sugar, some varieties are better suited to different temperatures and others can produce
in poorer soils. Some can tolerate drought and withstand salty soils. This means particular varieties
are selected for different regions of the country. Some varieties occur in most areas around the
country while other kinds are just localised in certain villages.
There are also important differences in disease and pest resistance between varieties.
The large number of varieties has been able to develop because in the tropics sugarcane can
both flower and produce seed that will grow.
Sugarcane as an industry
By far the biggest sugarcane industry in Papua New Guinea is the sugarcane people grow
and eat in villages. This is a very important industry and we should never be fooled into thinking
that sugarcane only becomes important in Papua New Guinea when people grow and process and
sell it commercially from plantations. From subsistence sugarcane at least 300,000 tons a year of
sugarcane are produced. For this, many varieties are maintained. Papua New Guinea is the home
of sugarcane and hundreds of varieties have been collected and used in breeding for most of the
sugarcane in the world. But even now in a village, one farmer may keep up to 20 or more varieties
of sugarcane. Some are early maturing and others later, some are soft and some hard. Some grow
very tall and some are shorter with many suckers. Each of these kinds is kept for reasons that are
important to the farmer concerned. They need soft kinds for old people with bad teeth, long kinds
for ceremonies and gift exchanges, and so on. With subsistence sugar, people want small amounts
produced daily, rather than large amounts produced in one season. They need different kinds to suit
different seasons. Most of this sugar grown and eaten in villages, is grown by intercropping with
other crops in food gardens. The methods and the pest and disease problems all work on the same
principles as commercial sugarcane but the way these things are organised is different.
Growing sugarcane
Within subsistence agriculture, by far the most common method of planting sugarcane is to
use the top of the cane. As buds quickly develop and grow from the nodes of the cane, sections of
the cane could be used, but in gardens the canes are normally used for chewing and the tops
planted.
Plants can be ready in 9-10 months but often are left to grow for 2 years or longer.
Although in good soils plants can be cut back and allowed to regrow many times, this is not
normally used in Papua New Guinea.
Tall canes have supporting poles to which they are tied to prevent them falling over and
breaking.
Sugarcane can make very efficient use of sunlight and the wide spacing used with
intercropping in subsistence gardens probably helps its growth.
Where is sugarcane grown?
Sugarcane grows in most areas of Papua New Guinea. Sugarcane grown in the highlands
grows more slowly but is sweeter. Therefore sugarcane is a more important part of gardening and
of the diet at altitudes over 1000 m. In many highland gardens sweet potato and sugarcane are the
two main crops grown.
For most rapid growth sugarcane needs a temperature between 32°-38°C. These conditions
occur on the coast. The average temperature for sugarcane needs to be about 21°C.
For sugarcane to become sweet and store lots of sugarcane it needs to have a check to its
growth. This can be provided by cool temperatures or by drought. That is why commercial
sugarcane is being established in the Markhum Valley where there is a seasonal dry period.
Varieties differ in how they respond to drought. Some can reduce water loss while others let
leaves dry off and die then re-establish new leaves quickly when it rains again.
289
Pests and disease
Many different diseases, insects and other pests like rats have been recorded damaging
sugarcane in Papua New Guinea. Often the same diseases and insects also damage other grasses
similar to sugarcane and damage coastal pitpit.
Sugarcane insect pests
Bugs sucking sap
Aleurodes comata
Amblypelta cocophaga China
Amblypelta costalis szentivanyi Brown
Amblypelta gallegonis Lever
Amblypelta lutescens papuensis Br.
Amblypelta theobromae Brown
Cicadella sp.
Leptocorisa acuta (Thunberg)
Leptocorisa oratorius (Fab.)
Leptocorisa solomonensis Ahmad
Lophops saccharicida Kirk.
Machaerota humboldti
Neomaskellia bergii (Signoret)
Perkinsiella bicaloris
Perkinsiella lalokensis
Perkinsiella papuensis
Perkinsiella rattlei
Perkinsiella vastatrix (Breddin)
Phaenacantha spp.
Plautia brunneipennis
Aphids
Aphis gossypii Glover
Aphis sacchari Zehntner
Ceratovacuna lanigera Zehntner
Myzus persicae Sulzer
Rhopalosiphum maidis (Fitch.)
Scales and mealy bugs
Aspidiotus destructor Sign.
Diaspis rutherfordi
Dysmicoccus brevipes (Cockerell)
Saccharicoccus sacchari (Cockerell)
Borers
Chilo terrenellus Pag.
Lepidiota reuleauxi Brenske (Arrow)
Maliarpha separatella Rag.
Mulciber linnaei Thoms
Papuana spp.
Rhabdoscelis obscurus (Boisduval)
Scoliophthalmus sp.
Sesamia grisescens Walker
Sesamia inferens (Walker)
Silba sp.
Trochorhopalus strangulatus Gyllenhal
Xyleborus perforans (Wollastan)
Eating leaves
Anomala anoguttata Burm.
Araecerus sp. (See Oxyderes)
Araeocorynus sp.
Arrhenes dschilus Plotz.
Atractomorpha crenaticeps Blanch
Austracris guttulosa Walk
Brontispa lateralis
Aleurodidae (HEM)
Coreidae (HEM)
Coreidae (HEM)
Coreidae (HEM)
Coreidae (HEM)
Coreidae (HEM)
Cicadellidae (HEM)
Alydidae (HEM)
Alydidae (HEM)
Alydidae (HEM)
Lophopidae (HEM)
Machaerotidae (HEM)
Aleyrodidae (HEM)
Delphacidae (HEM)
Delphacidae (HEM)
Delphacidae (HEM)
Delphacidae (HEM)
Delphacidae (HEM)
Colobathristidae (HEM)
Pentatomidae (HEM)
Green coconut bug
Papuan tip wilt bug
Tip wilt bug
Severe brown spotting of leaves
Paddy bugs
Paddy bugs
Paddy bugs
Sugarcane white fly
Sugarcane leafhoppers
Sugarcane leafhoppers
Sugarcane leafhoppers
Sugarcane leafhoppers
Sugarcane leafhoppers
Sugarcane bug
Stink bugs
Aphididae (HEM)
Aphididae (HEM)
Aphididae (HEM)
Aphididae (HEM)
Aphididae (HEM)
Melon aphid
Sugarcane aphid
Sugarcane woolly aphid
Green peach aphid
Corn leaf aphid
Diaspididae (HEM)
Diaspididae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Coconut scale
Pyralidae (LEP)
Scarabaeidae (COL)
Pyralidae (LEP)
Cerambycidae (COL)
Scarabaeidae (COL)
Curculionidae (COL)
Chloropidae (DIPT)
Noctuidae (LEP)
Noctuidae (LEP)
Lonchaeidae (DIPT)
Curculionidae (COL)
Scolytidae (COL)
Sugarcane borer
Ramu canegrub
White stem borer
Rutelidae (COL)
Anthribidae (COL)
Anthribidae (COL)
Hesperiidae (LEP)
Acrididae (ORTH)
Acrididae (ORTH)
Chrysomelidae (COL)
Pineapple mealy bug
Sugarcane mealybug
Taro beetles
New Guinea sugarcane weevil
Larvae boring into stems
Stem borer
Violet rice stem borer
Larvae boring into stems
Adults bore into stems near ground
Larvae and adults bored into
sugarcane stems at ground level
Moderate damage
Slight damage
Spur throated locust
Cirphus unipuncta Haw
Dasychira horsfieldi Saunders
Elassogaster sepsoides Walk.
Enoplopteron ?hieroglyphicum de Miej
Gesonula mundata sanguinolenta Kraus
Gryllotalpa africana Pal.
Heteropternis obscurella (Blanch)
Hypolixus ritsemae Pasc.
Agrotidae (LEP)
Lymantriidae (LEP)
Platystomididae (DIPT)
Tephritidae (DIPT)
Acridiidae (ORTH)
Gryllotalpidae (ORTH)
Acrididae (ORTH)
Curculionidae (COL)
Locusta migratoria (Linnaeus)
Melanitis constantia Cramer
Mythimna loreyi (Dup.)
Mythimna separata (Walk.)
Opogona saccharella
Orinaeme sp.
Oryctes rhinoceros (L.)
Oxya vittigera (Blanch)
Pachybrachius nervosus Horv.
Patanga sp.
Phaciocephalus sp.
Phragmatiphila truncata
Protaetia fusca Herbst.
Rhyparida coriacea Jac.
Rhyparida morosa Jac.
Spodoptera exempta (Walker)
Spodoptera mauritia (Boisduval)
Stenocatantops augustifrons (Walker)
Tauchiridea adusta Bolivar
Tettigella pasiphae Kirk
Valanga irregularis (Walker)
Acrididae (ORTH)
Satyridae/Nymphalidae (LEP)
Noctuidae (LEP)
Noctuidae (LEP)
Hieroxestidae (LEP)
Cerambycidae (COL)
Scarabaeidae (COL)
Acrididae (ORTH)
Lygaeidae (HEM)
Acrididae (ORTH)
Derbidae (HEM)
Agrotidae (LEP)
Scarabaeidae (COL)
Chrysomelidae (COL)
Chrysomelidae (COL)
Noctuidae (LEP)
Noctuidae (LEP)
Acrididae (ORTH)
Acrididae (ORTH)
Cicadellidae (HEM)
Acrididae (ORTH)
Amblypelta bug
Plautia
Ramu canegrub
Atractomorpha
Leptocorisa bug
Sugarcane aphid
White stem borer
Austracris
Cutworm
On sugarcane
Lophops
Peach aphid
Asiatic rhinoceros beetle
Bands of grasshoppers
Adults fed on leaf sheaths
Mango flower beetle
African armyworm
Paddy armyworm
Slight damage to sugarcane foliage
Giant grasshopper
Perkinsiella leafhopper
Corn leaf aphid
NG Sugarcane weevil
African mole cricket
291
African mole cricket
Damage slight
Long narrow areas had been chewed
in leaves but damage was slight
Migratory locust
Larvae feeding on leaves
Rice armyworms
Rice armyworms
Phaeacantha
Sugarcane borer
Sesamia stem borer
Migratory locust
Violet stem borer
Sugarcane diseases
Red rot leaf sheath
Eye spot
Pineapple disease
Veneer blotch
Brown stripe
Pokkah boeng
Red rot
Ring spot
Yellow spot
Downy mildew
Rind disease
Tar spot
Rust, orange
Red leaf streak
Leaf scorch
Ramu stunt
Red stripe
Fiji disease
Mosaic
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Fungus
Athelia rolfsii
Bipolaris sacchari
Ceratocystis paradoxa
Deightoniella papuana
Dreschlera stenospila
Gibberella fujikuroi
Glomerella tucumanensis
Leptosphaeria sacchari
Mycovellosiella koepkei
Peronosclerospora sacchari
Phaeocytostroma sacchari
Phyllachora sacchari
Puccinia kuehnii
Ramulispora sacchari
Stagnospora sacchari
Bacteria
Virus
Virus
Pseudomonas rubrilineans
Sugarcane Fiji disease virus
Brown spot of sugarcane is caused by a fungus Cercospora longipes Butler. Brown spots form on the older leaves.
They are long and oval in shape 13 mm by 1 mm. The spots are paler on the lower surface. There may be a pale
yellow ring around the spots. They are similar to those of yellow spot. (Mycovellosiella koepkei). Presumably the
disease spreads by wind blown spores. It can cause moderate damage to leaves causing them to die off. Some kinds of
sugarcane get less damage. To help with control gardeners should a void taking plants that have the disease on the
leaves to their new gardens. The disease is described in the CMI Descriptions of Pathogenic Fungi No 418
Brown stripe sugarcane is caused by the fungus Bipolaris stenospila (Drechsler) Shoem. The disease spots are long
and thin. (25 mm or more long). This makes them form streaks but they do not have a shape like eye spot. (Bipolaris
sacchari). When spots join large dead areas may form. The fungus that causes the disease grows best at 28° to 32°C.
The disease gets more severe in dry weather, and when sugarcane is not growing well. It is presumed that the spores of
the fungus blow in the wind. Damage can be serious with some varieties but many sugarcane varieties have resistance.
So it is important to use varieties that get less disease. The disease is described in the CMI Descriptions of Plant
Pathogenic Fungi No.306 and map 483. Also by Krishnamurthi,M., & Koike,H.,1982, Sugarcane collecting expedition:
Papua New Guinea,1977. Hawaiian Planters' Record 59(13) 273-313.
Downy mildew of sugarcane also affects Coastal pitpit and is caused by the fungus Peronosclerospora sacchari (Miy.)
Shirai & Hara. Long light green stripes occur on the leaf. These may have white spots and leaves may strip into shreds.
Older stripes may turn yellow. Fine white soft down can sometimes be seen. Young leaves get attacked first. The
disease spreads when the temperature is about 25°C and there is a high relative humidity. It can spread in infected
planting material. The disease mostly attacks the plant through the young buds on the stem. The spores (conidia)
spread mostly in the middle of the night. They can blow 400 m in the wind. Growth of the sugarcane is restricted.
Plants infected early can die. A number of grass plants can be attacked - sugarcane, sorghum, pitpit, Setaria and
maize/corn. Some varieties of sugarcane get less disease. Healthy planting material should be used. Crops in grassland
may be more attacked. It is important to get rid of diseased plants including nearby crops. Sugarcane sets can be
treated with hot water (52°C for 1 hour) or chemicals. The disease is described in the CMI Descriptions of Pathogenic
Fungi No. 453. Also by Leu, L.S. & Egan, B.T., in Ricaud, C et al, 1989, Diseases of Sugarcane. Elsevier p 107-117.
Eyespot of sugarcane is caused by the fungus Bipolaris sacchari (Butler) Shoem. Several small red-eyed spots
develop on young leaves of sugarcane. These start about 1 mm x 1 mm across and grow to 3-6 mm x 5-12 mm across.
They have a narrow yellow area around them. Large areas of leaf can die. Sugarcane must have moisture on the leaves
for the disease to get started. Dew is more important than heavy rain. It is commonest in cooler months. Plants get
worse damage when they are growing very quickly. Temperatures need to be less than 25 °C. The fungus spreads by
wind, and rain. It can be spread on machinery. Badly infected sugarcane can produce a lot less food. Elephant grass
and lemon grass can also get the disease. Some varieties of sugarcane are more resistant so get the disease less. Too
much nitrogen fertiliser should not be used. The disease is described in CMI Descriptions of Pathogenic Fungi No 305
& Map 349. Also by Comstock, J.C., & Steiner, G.W. in Ricaud, C. et al, 1989, Diseases of Sugarcane. Elsevier. p 123129. Frohlich, G. et al , 1970, Pests and Diseases of Tropical Crops. Pergamon. p 235 Plate 35. and Holliday,P.,1980,
Fungus Diseases of Tropical Crops. Cambridge. p 144.
Fiji disease of sugarcane is caused by Fiji Disease Virus (FDV). The sugarcane leaves become distorted and lumps
and galls develop on the undersurface of the leaves. When leaves are growing quickly new leaves can be shorter and
stiffer and look like a fan. The plant can be stunted. The disease occurs from the coast to the highlands. The disease is
spread by a small sap sucking sugarcane leafhopper insects Perkinsiella spp.. The disease can also be spread if planting
material is taken from a plant which already has the disease. It cannot be spread on tools like bush-knives. The adult
leafhoppers move in large numbers on nights with no wind. They sometimes move towards lights. The number of
insects varies depending on highly favoured varieties of sugarcane being available. Plants can die. The disease can be
serious if varieties of cane that favour the leafhopper and the disease are present. Coastal or long pitpit can also get the
disease. To control the disease healthy planting material should be used as well as resistant varieties. Infected plants
should be harvested early then the remainder of the plant destroyed. The disease is described in CMI Distribution Map
17 and by Egan, B.T., et al in Ricaud, C., et al, 1989, Diseases of Sugarcane. Elsevier. p 265-280 and Kula, G.R., Plant
Pathology Note No 10 or Harvest 7(2) p 89
Leaf scorch of sugarcane is caused by the fungus Stagonospora sacchari Lo & Ling. Very small red spots develop on
the leaves. They gradually become long and develop a yellow ring around the edge. Finally spots can be 20 cm x 1 cm
in size. The disease spreads most rapidly when temperatures are between 20 °-25°C. Wind blown rain and dew are
essential for the fungus to spread. Infected canes store less sugar. Some wild grasses in the sugarcane family can get
the disease. Some varieties get less disease and should be used. The diseases is described in CMI Descriptions of
Pathogenic Fungi No. 418 and by Lo, T.T. & Leu, L.S., in Ricaud, C.,et al, 1989, Diseases of Sugarcane. Elsevier. p
135-140.
Leaf spot or ring spot of sugarcane is caused by the fungus Leptosphaeria sacchari v.Breda de Haan. Dark green
spots with narrow yellow edges develop on leaves. These can become oval and irregular in shape and form dark
reddish patches. The spots are more common on older leaves. The disease is probably caused by a fungus but this
fungus may start to grow after other fungi have damaged the leaf. The spores of the fungus blow in the wind and are
washed by rain. They can live for an extended time on old dead leaves. The disease is not normally serious but it may
reduce seedling growth in some varieties. Control is not normally required. The disease is described in Abbott, E.V., in
Hughes, C.G. et al (ed)., 1964, Sugarcane diseases of the world. Vol 1 p 53-58 and CMI Description of Pathogenic
Fungi No 145 and Distribution Map No 330
Orange rust of sugarcane also affects Coastal pitpit and is caused by the fungus Puccinia kuehnii (Krug.) Butler.
Small long yellow rust spots develop on both sides of leaves. These spots get longer and turn brown. Then an orangebrown rust pustule breaks out. The lumps occur in groups on the lower half of the leaf. (Another rust called common
rust (Puccinia melanocephala) is spreading to most countries of the world, probably in the wind. It suits the highlands.
18° C.) The disease probably gets worse when temperatures are between 20°-25°C and up to 30°C and humidity of 7090%. Cloudiness and wind help spread the disease. It is spread by wind and rain. The disease is not normally serious
but leaves may die early. Sugarcane, coastal pitpit and wild Saccharum pitpit grasses also get the disease. For control,
use varieties with high levels of resistance. Other control is not normally required. The disease is described in CMI
Descriptions of Pathogenic Fungi No 10 and by Ryan, C.C.& Egan, B.T. in Ricaud, C et al, 1989, Diseases of
Sugarcane. Elsevier. p 189-202.
Pineapple disease of sugarcane is caused by the fungus Ceratocystis paradoxa (Dade) Moreau. With this disease,
sugarcane setts turn red then rot. They have a smell like pineapples. The disease is caused by a fungus. The fungus
normally occurs in the asexual or imperfect form. Small long spores and larger curved spores are produced in chains.
It likes warm conditions between 25°-32°C such as on the coast in Papua New Guinea. When soils are cold and wet the
sugarcane cuttings start to grow more slowly which gives the disease more time to attack the plants. The fungus gets
spread from the soil by rain and wind. It gets into damaged and cut stalks more easily. Wind blown spores can get into
canes through rat damage etc. The fungus can last in the soil for quite a long time. Sugarcane setts can rot completely
and not grow. The fungus also damages pineapples, coconuts, oil palm and bananas. Sometimes it damages betel nut
palm and other palms, soursops, sweet potato, corn and other plants. Control is by using healthy planting material and
providing good growing conditions such as a warm, well-drained, moist soil. Diseased setts should be removed.
Cuttings can be soaked in benomyl solution (1 part in 1600 parts of water). The disease is described in CMI
Descriptions of Pathogenic Fungi No 143 & Map 142 and by Wismer, C.A. & Bailey, R.A. in Ricaud, C.,et al, 1989,
Diseases of Sugarcane Elsevier. p 145-151.
Pokkah Boeng of sugarcane also affects Coastal pitpit and is caused by the fungus Gibberella fujikuroi (Sawada) Ito
apud Ito & Kimura. Young sugarcane leaves go yellow near the base, and leaves are wrinkled and red areas can occur.
Stems can also be distorted. The disease gets worse in very wet weather especially when this follows a dry period.
Cane between 3 to 7 months old and growing rapidly gets most disease. The disease can spread from the soil or
through cut stalks or in the air. It is a fairly common but not very serious disease. Sets may not grow. When the disease
gets bad, plants can die. It occurs on many grass plants including maize, rice, sugarcane and pitpit. It causes pink ear
rot of corn and foot rot of rice. Some varieties have resistance. Sugarcane sets can be dipped in benomyl fungicide.
Excessive amounts of nitrogen fertiliser should be avoided. The disease is described in CMI Descriptions of Pathogenic
Fungi No 22 and by Martin, J.P., et al in Ricaud et al, 1989, Diseases of Sugarcane. Elsevier p 157-165.
Ramu scorch of sugarcane has an unknown cause. Large straw-coloured spots with red-brown edges occur on leaves.
The spots have a yellow ring around them. In some varieties the spots joined to kill the leaves. Damage can be severe
293
in susceptible varieties. So for control use varieties that get less damaged by disease. The disease is described in Egan,
B.T., New diseases appear in Papua New Guinea. BSES Bulletin (1986) No 16, 8-10.
Ramu stunt of sugarcane is probably caused by a virus or mycoplasma. White to pale yellow-green stripes occur on
leaves. The growth rate is reduced and roots develop poorly. It spreads very rapidly. It causes serious loss in yield.
The disease is described in Egan, B.T. New Diseases appear in Papua New Guinea. BSES Bulletin (1986) No 16, 8-10
and by Waller, J.M., Egan, B.T. & Eastwood, D., 1987, Ramu stunt, an important new sugarcane disease in Papua New
Guinea. Tropical Pest Management 33(4),347-349.
Red rot of sugarcane also affects Coastal pitpit and is caused by the fungus Glomerella tucumanensis (Speg.)Arx &
Muller. Red areas with white flecks occur within the stems. Small red spots can occur on the leaf sheath especially
near the midrib. The buds get damaged & a poor stand of cane is produced. Stalks need to be cut lengthwise to check
red and white patches in the stalk. Damaged stems, including borer damage, allows the disease to get started. It gets
worse in cooler areas. The fungus can spread from the soil or old crop remains. Spores can be blown by wind. It can
be spread in planting material. The fungus can only live for 6 months in the soil. Plants grow less well and can die.
Sugarcane is less sweet. The disease occurs on Saccharum and Sorghum grasses. For control don't plant diseased
material and get rid of diseased plants. Different varieties have different amounts of resistance. The fungus in canes for
planting can be killed with hot air treatment. It is important to rotate sugarcane crops. The disease is described in CMI
Descriptions of Pathogenic Fungi No 133 & Map 186 and by Singh, K.& Singh, R.P., in Ricaud, C.et al, 1989, Diseases
of Sugarcane. Elsevier. p 169-182
Red stripe of sugarcane is caused by bacteria Pseudomonas rubrilineans (Lee et al) Stapp. It can cause leaf stripe and
top rot. The leaf stripe has long narrow, uniform, dark-red stripes. They may start as watery-green stripes but become
red. The disease is more commonly on young leaves. It gets worse with high humidity. It is worse in cool places. It
spreads with wind blown rain. The bacteria ooze onto the surface of leaf spots during moist warm weather. This can
wash down plants or splash between plants. It is rarely transmitted by cane knives. It can lie in the soil for a month and
on old dead plants for up to 7 months. It can cause the top of plants to rot. It can also occur on sorghum grasses and
maize. For control, use resistant varieties. Changing the planting dates can reduce top rot of seedlings in some areas.
The disease is described in CMI Descriptions of Pathogenic bacteria No 127 and Distribution Map 39. Also by
Haywood, A.C. in Fahy, P.C. & Persley, G.J. (eds), 1983, Plant Bacterial Diseases. A Diagnostic Guide. Academic. p
124-127, And by Martin, J.P. & Wismer, C.A., in Ricaud, C et al, 1989, Diseases of Sugarcane. Elsevier. p 81-91.
Rind disease of sugarcane is caused by a fungus Phaeocytostroma sacchari (Ell.& Ev.) B Sutton. Leaves may turn
yellow early due to the fungus on the leaf sheaths. Black spots like pimples (pustules) on the stalks can give off black,
coiled, hair like masses of spores under moist conditions. The disease gets worse where there is low temperatures, high
salinity, poor drainage, and mechanical damage to cane for planting. The small fungal spores blow in the wind or rain.
It gets on seed cuttings and reduces their germination. It can seriously affect over mature cane causing the stalks to rot.
It occurs on plants in the sugarcane group. Some varieties of sugarcane get worse damage. Harvest the sugarcane when
it is mature especially if it has suffered injury to the stalks. The disease is described in the CMI Description of
Pathogenic Fungi No 87 and Distribution Map 255
Sugarcane mosaic is also called yellow stripe disease and is caused by the sugarcane mosaic virus. A pattern of light
green and dark green areas, develop on the leaves. The pale areas can be most easily seen in young rapidly growing
leaves. Sometimes these are just yellowish stripes but there can be large yellowish patches. The pale areas can also be
on the leaf sheath and the cane stalk. The virus can be spread by aphids (eg corn leaf aphid Rhopalosiphum maidis) and
sugarcane aphid (Longiunguis sacchari). It can also be spread mechanically with things like bush knives. It can spread
from infected planting material. The damage can be serious with kinds of sugarcane that get the disease easily.
Sometimes plants can recover from the disease. It also occurs in maize, sorghum and on many other grasses. Control is
by using disease free planting material and kinds of sugarcane that get the disease less. The disease is described in the
CMI Distribution Map 330 and by Koike, H.& Gillaspie, A.G., in Ricaud, C et al, 1989, Diseases of Sugarcane.
Elsevier. p 301-314.
Tar spot of sugarcane also affects Coastal pitpit and is caused by the fungus Phyllachora sacchari P.Henn. Black tar
like spots occur on the leaves. The disease probably spreads by wind and rain spreading spores from infected crop
debris. Leaves can dry up in serious cases. It is not normally serious. Sugarcane, coastal pitpit, sorghum, and other
Sorghum and Saccharum grasses also get the disease. No control is normally required. The disease is described in the
CMI Descriptions of Pathogenic Fungi No 588 and by Holliday, P.,1980, Fungus Diseases of Tropical Crops.
Cambridge. p 330.
Veneer blotch of sugarcane also affects Coastal pitpit and is caused by a fungus Deightoniella papuana D.Shaw. The
disease causes a distinct pattern on the upper surface of the leaves. It begins as a small oval leaf spot, light green with a
red border. New long spots develop on either side of the original spot forming a long patterned leaf spot. Sugarcane,
long pitpit and other sugarcane type grasses get the disease. The disease is described by Holliday,P., 1980, Fungus
Diseases of Tropical Crops. Cambridge. p 1124 and Shaw, D.E.,1959, PNG Ag. J. 11(1956):77
Yellow spot of sugarcane also affects Coastal pitpit and is caused by a fungus called Mycovellosiella koepkei
(Kruger)Deighton. Different races of the fungus occur which means vertical resistance introduced by plant breeders
can break down. On the young leaves of sugarcane and coastal pitpit small yellow pinpoint spots appear. These spots
later join and become irregular in shape. The disease gets worse during wet, humid weather and high temperatures
(28°C). Humidities over 80% are possibly necessary. The spores (conidia) are washed off leaves. Although it does not
spread on sets where pieces of the stalk are used it probably can spread on tops as used in Papua New Guinea. The
leaves of sugarcane and pitpit die early. Some varieties get less of the disease (Traditional varieties are less damaged
than hybrids.) The disease is described in the CMI Descriptions of Pathogenic Fungi No 417 & Map 341 and by
Holliday, P, 1980, Fungus Diseases of Tropical Crops. Cambridge. p 71; Martin, J.P. et al ,1961, Sugarcane Diseases of
the World. Vol 1. Elsevier. p 357ff and by Ricaud, C.& Autrey, L.J.C. in Ricaud, C et al,1989, Diseases of Sugarcane.
Elsevier. p 231-241.
Sugarcane leaf spots
Nitrogen deficiency of sugarcane
295
TON
Scientific name: Pometia pinnata
Names
The tree that is called Ton (or Taun) in Tok Pisin was first described in 1776 by the
botanists J.R. & G Forster. They gave it the scientific name Pometia pinnata. The name Pometia
comes from a Latin word "pomum" which means fruit or apple. The other part of the name,
pinnata, describes the way the leaflets grow opposite each other along a stalk. In many people's
minds, these two things are typical of the tree - leaflets drooping from long stalks and a very
enjoyable fruit.
Ton trees can vary a lot, and different forms or types of the tree have been described. Some
types do not have edible fruit. Two main types are called:
Pometia pinnata JR & G Forster forma pinnata
and
Pometia pinnata JR & G Forster forma tomentosa.
In some books these were described as two different species. They are in the plant family
called Sapindaceae.
The tree
A ton tree can grow into quite a large tree up to 40 metres high. At the base of the tree there
are often large buttresses and the bark is a bright orange brown colour and rough and scaly. The
young leaves and twigs of the tree are bright red.
The lowest pair of leaflets are small and clasp the stem like stipules. There are often 5-11
pairs of leaflets along a stalk and the leaflets at the centre are often the largest.
The flowers are produced in clusters on stalks that are up to 50 cm long and grow near the
ends of the branches. The flowers are small and yellowish green and do not have any scent.
Several varieties of ton occur, but the main part that varies is the colour of the fruit. Young
fruit are green, but as they get ripe the colour can change to green, yellow, red or purple depending
on the variety. They all taste much the same.
The fruit
In Papua New Guinea in coastal areas and on the islands this is one of the most popular
fruits. The fruit is a bit like a rambutan, or a litchi, two fruits that are better known from Malaysia
and China. The edible part is a white shiny layer around the seed. Scientists call this layer the aril.
When a ton fruit is ripe, the skin peels off very easily, just like peeling a mandarin.
Where do the trees grow?
Ton trees only grow in SE Asia. The trees occur in Sri Lanka, Malaysia, Indonesia,
Philippines, Papua New Guinea and some Pacific Islands.
The tomentosa type does not have fruit that can be eaten or if it is eaten it is much less
attractive. It tends to grow on hill slopes and ridges between an altitude of 900 and 1200 metres. It
is normally in well-drained positions. The type that has edible fruit is more commonly in the
lowland rainforest, on riverbanks and in poorly drained places. It is this second type that is an
important food plant.
Fruit production
Ton fruit are produced seasonally. The season is near Christmas, (December/January) and it
tends to be short and a very distinct season with few trees bearing early or late. Sometimes there is
a minor season in mid-year about June and July. These fruit are not as sweet. The season does not
exactly coincide in different provinces of the country, and it can be a month or two later in New
Ireland. As well, trees do not fruit equally well each year. On Manus Island, ton trees only produce
a lot of fruit every few years. These good seasons then become times of great excitement and
happiness. (Yen, in his study of this tree in the Solomon Islands said that flowers formed later in
the year often did not set fruit. It appears that some fruit setting problem occurs, which needs
study.)
Growing ton
Ton are planted from seed. Also self sown seedling are transplanted and some trees occur
wild in the bush. The seeds are probably spread around by fruit eating bats. It probably takes about
5 years from planting until the trees bear fruit.
In the Solomon Islands, and in Malaysia, ton seeds are eaten after they are roasted. Also in
the Solomons, ton leaves are chewed with lime. It is not known if either of these practices occurs in
Papua New Guinea. The actual seeds have been reported as poisonous without treatment.
297
Watermelon
Scientific name: Citrullus lanatus
The plant
The watermelon plant is a climbing pumpkin family plant. The leaves and vines are hairy
and it has tendrils enabling it to cling onto things. The leaves are up to 20 cm long and have 3 to
seven lobes. The flowers are yellow and about 2 cm across. There are male and female flowers.
The fruit vary in shape from round to oval and from green skinned to kinds streaked with various
shades of green. The flesh is red or yellow. There are black flattened seeds in amongst the flesh.
Because the plants cross-pollinate considerable variation exists between the plants.
Growing watermelons
It suits dry areas or can be grown in the dry season in other places. It is grown on the coast
and up to about 1000 metres altitude. It suits sandy soils and is commonly seen and grows well on
the sandy soils around Port Moresby. It must have a well-drained soil. It requires a high
temperature for best production. The seeds germinate best where temperatures are between 24° and
30 °C. Fruit ready for harvest can be produced in 3 months from planting. Seed will keep for 2
years if carefully stored, dry.
Seed is sown 1 cm deep and with plants about 1 to 1.5 metres apart. Seed germinate within a
week. If large fruit are desired they fruit should be thinned out to 2 or 3 per plant. It is not easy to
tell when fruit are ripe but looking at the tendril near the fruit to see if it has wilted, watching a
slight colour change from white to yellow where the fruit rests on the ground and tapping the fruit
for a dull sound all give some indication. The fruit can be stored for 2 or 3 weeks in a cool place.
The flesh of the fruit is sweet and watery and provides a refreshing substitute for a drink.
The seeds are eaten raw or cooked. Small unripe watermelons can also be cooked as a vegetable.
Pests and disease
Watermelon diseases
Leaf spot
Leaf spot
Black rot
Powdery mildew
Damping off
Mosaic
Root knot
Cercospora citrullina
Colletotrichum lagenarium
Leptosphaerulina trifolii
Mycosphaerella melonis
Oidium sp.
Pythium irregulare
Fungus
Fungus
and
Fungus
Fungus
Fungus
Probably virus
Nematode
Meloidogyne incognita
Watermelon insect pests
Tiracola plagiata Walk
Dacus cucurbitae Coq
Planococcus pacificus Cox
Noctuidae (LEP)
Tephritidae (DIPT)
Pseudococcidae (HEM)
Cacao armyworm
Melon fruit fly
Wrapping the fruit with paper while growing can help reduce fruit fly damage.
299
Nuts
Aila
Breadfruit family
Candlenut
Castanopsis chestnuts
Coconut
Galip nuts
Finschia nuts
Karuka family
Terminalia
302
305
310
312
314
316
318
324
328
331
338
341
343
347
348
350
Breadfruit
Jackfruit
Parartocarpus
Karuka
Wild karuka
Pandanus antaresensis
Okari
Talis
Java almond
Pao nuts
Aila
Parartocarpus
Breadfruit
Candle nut
Jackfruit
Castanopsis nuts
Galip
Coconut
Finschia
Karuka
Pandanus
Wild karuka
Okari
Talis
Coastal
almond
Pao
301
Aila
Scientific name: Inocarpus fagifer
What is an aila tree like?
An aila or Tahitian chestnut is a large tree 20 metres or more tall and with buttresses at the
base of the trunk. The bark is dark grey and gives a red sap when cut. The branches droop
downwards.
The leaves are long (20 cm), leathery, shiny and feather veined. The leaves have short
stalks and are one after the other (alternate) along the branch. Young leaves are pink.
The flowers of aila are not obvious. They are pale yellow and hang loosely on the twigs
from the angles where leaves join. They have 5 narrow petals joined in a tube. The flowers smell
sweetly.
The fruit is irregular or kidney shaped and has one seed inside. The outside of the pod is
thick and leathery with a lumpy surface. It can be 8-10 cm across and 3 cm thick. The ripe fruit is
yellow.
The fleshy layer around the seed is eaten.
Where do aila nut trees grow?
Aila nut trees grow near sea level. Often they are very close to the waterfront. They are
common on some of the off shore islands.
They can grow in swampy ground and are common in some river estuaries.
Trees can probably grow from sea level up to about 300 m altitude. They do better where
there is no distinct dry season.
Aila nut trees do not only occur in Papua New Guinea but occur in some other South East
Asian and Pacific countries as well. The map shows places where the trees occur naturally or
commonly.
Map from Balgooy Pacific Plant areas
The countries include Malaysia, Indonesia and Pacific islands such as Fiji, Tahiti and Samoa
as well as Papua New Guinea.
Growing Aila nuts
Aila nut trees often grow self-sown. The fruits are distributed by bats and other animals,
although the seeds float easily as well.
Trees can be grown from seed. Trees can commence producing fruit about 8 years after
planting. It is also possible to grow trees from cuttings.
Aila nuts are produced seasonally. The season is about the beginning of the year probably
from January to May.
303
Insect pests of Tahitian chestnut
Scales and mealy bugs
Ischnaspis longirostris (Signoret)
Lepidosaphes rubrovittata Cockerell
Parlatoria crotonis Douglas
Pinnaspis aspidistrae (Signoret)
Pinnaspis buxi (Bouche)
Pinnaspis strachani (Cooley)
Icerya seychellarum (Westwood)
Ceroplastes rubens Maskell
Coccus longulus (Douglas)
Coccus viridus (Green)
Neoplatyolecanium sp.
Dysmiccocus brevipes (Cockerell)
Maculicoccus malaitensis (Cockerell)
Planococcus pacificus Cox
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Margarodidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Black thread scale
Pink wax scale
Green scale
Pineapple mealybug
Aila nuts as food
The nuts are usually roasted although they can be boiled.
Soaked nuts can be grated, mixed with coconut milk and roasted in banana leaves.
Seeds can be stored by partly fermenting them in pits in the ground.
Nuts can be stored for a considerable time but once shelled or cooked will only keep a short
time.
The wood of the tree is good for firewood.
Food value per 100 g edible portion:
Edible portion
Nut
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
43.0
1008
4.5
0
2
Iron
mg
Zinc
mg
The breadfruit family
Breadfruit
Artocarpus altilis
Jackfruit
Artocarpus heterophyllus
Pakal
Parartocarpus venenosa
Also Artocarpus vrieseanus
305
Breadfruit
Tok Pisin: Kapiak
Scientific name: Artocarpus altilis
The breadfruit tree
The breadfruit tree is a large tree often up to 15 or 20 metres tall. It has large, rough leaves
that vary in how much they are divided around the edge. It produces male and female flowers
separately but near each other on the same tree. It has a white sticky sap that leaks out from
damaged parts of the bark.
Where is breadfruit grown?
The breadfruit tree is grown not only in Papua New Guinea but also in a number of other
Pacific Island countries. It has also been taken to a number of other countries such as the West
Indies. There is a famous story about one of the early explorers who tried to take a shipload of
breadfruit trees to the West Indies. All the men on the boat refused to sail the ship any further so
the crew were put off the boat on a small Pacific Island called Pitcairn.
But the breadfruit that is most common in the Western regions of Papua New Guinea is
fairly different from the breadfruit that is grown on the coast and islands and in other Pacific
countries. This is because the people in these places have picked out breadfruit that are full of
seeds. It is these seeds that are eaten.
A breadfruit in the Western areas of Papua New Guinea looks fairly different from the
breadfruit that coastal people know. This breadfruit has a lot of soft pointed spines all over the
fruit. The breadfruits on the New Guinea islands have fruit with small rounded lumps all over
them.
Breadfruit can be seen growing up to about 1200 metres altitude above sea level. It is not
common at 1200 metres but becomes fairly common at places lower down.
Breadfruit seeds
A breadfruit seed weighs about 5 grams and is
about 3 or 4 centimetres across.
A seed looks like this
drawing
Growing breadfruit
Most of the seeded breadfruit is grown from seed. The seeds are often self-sown by birds
and bats. These trees just come up naturally. Trees are also planted by people and some trees are
transplanted from where the seeds grew naturally. Normally seeds should be planted fresh before
they have dried out.
People have several different named varieties of their seeded breadfruit. These seem to
continue to produce a similar variety of tree even when grown from seed.
Breadfruit can be grown from root cuttings and this method could be used if it were
important to maintain a good kind of tree. This is the method used for the seedless types.
307
A shoot growing
from a root of a
seedless breadfruit
Pest and diseases
Breadfruit insect pests
Abgrallaspis cyanophylli (Signoret)
Aonidiella aurantii (Maskell)
Aspidiotus destructor Sign.
Ceroplastes rubens Maskell
Chrysomphalus aonidum (Linnaeus)
Coccus hesperidium Linnaeus
Coccus longulus (Douglas)
Bactrocera umbrosus (F.)
Dysmiccocus brevipes (Cockerell)
Dysmicoccus nesophilus Williams
Ferrisia virgata (Cockerell)
Hemiberlesia palmae (Cockerell)
Icerya seychellarum (Westwood)
Kilifia acuminata (Signoret)
Maconellicoccus hirsutus (Green)
Milviscutulus mangiferae (Green)
Mutabilicoccus vanheurni (Reyne)
Parasaissetia nigra (Nietner)
Pinnaspis strachani (Cooley)
Planococcus pacificus Cox
Pseudococcus longispinus Targioni
Pseudaulacaspis pentagona (Targ.)
Saissetia coffeae (Walker)
Telostylinus sp
Xyleborus spp.
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Tephritidae (DIPT)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Diaspididae (HEM)
Margarodidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Coccidae (HEM)
Diaspididae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Neriidae (DIPT)
Scolytidae (COL.)
Yellow scale
Coconut scale
Pink wax scale
Florida red scale
Soft brown scale
Fruit fly
Pineapple mealybug
Hibiscus mealy bug
Nigra scale
Longtailed mealybug
White scale
Coffee scale
Island pinhole borer
Breadfruit diseases
Leaf spot
Rust
Pseudocercospora artocarpi
Uredo artocarpi
Fungus
Fungus
Rust
Leaf spot
Leaf shapes vary considerably
Male flowers have a sweet smell and are burnt to keep mosquitoes away
Breadfruit as food
The young leaves and the male flowers can be eaten after cooking.
The seeds are cooked by roasting or boiling then eaten.
Seedless fruit are cooked and eaten.
Food value of 100 g edible portion:
Edible portion
Fruit
Leaves
Flowers
Seed
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
74.4
506
1.5
4
25
0.4
0.2
56.5
799
7.4
26
6.6
3.7
0.9
309
Jackfruit
Scientific name: Artocarpus heterophyllus
What is a jackfruit like?
The jackfruit tree is a large evergreen tree in the breadfruit family. Trees can be up to 20 m
high.
The leaves are entire and leathery.
Flowers occur on spikes on stalks from the trunk or main branches. Some stalks only have
male flowers, others only have female flowers while some have both male and female spikes.
The fruit are very large and hang from the trunk and the main branches. Fruit can be 60 cm
long and weigh up to 30 kg in weight. They have spikes or prickles all over the surface of the fruit.
Fruit are long and green. The flesh inside is yellow. The seeds are large and oblong with a slimy
membrane over it and a brown skin.
The trees have a thick milky sap. Leaves can be 22 cm long.
Names
The scientific name is Artocarpus heterophyllus. Two other scientific names have also been
used. These are Artocarpus integrifolia and Artocarpus integra. These names are no longer
correct.
Where do jackfruit grow?
Jackfruit are less tropical than breadfruit and can be grown in cooler places. They will
probably grow up to 2000 metres or more altitude. A warm wet climate is best. The soil needs to
be well drained but otherwise a variety of soils will produce good jackfruit.
How do you grow jackfruit?
Often jackfruit are grown from seeds. Seeds need to be fresh or they won't grow. Seeds
grow more quickly if they are soaked in water for 24 hours. Seeds germinate in about 3 weeks and
need to be sown where the tree is to be grown as seedlings do not transplant easily. This is because
the seedlings have a long delicate taproot.
Trees need to be spaced 12 to 14 metres apart.
Jackfruit trees grow quickly. A tree starts producing fruit about 4 to 6 years after planting.
Fruit take about 100 to 120 days from when the flower is pollinated until a fully mature fruit is
developed but can take another 4 months to ripen. Fruit are available most of the year round
although the main season is October to May. Often trees have larger crops every second year.
Jackfruit as food
The flesh between the seeds of the fruit is edible. The seeds can also be eaten after they are
cooked. The young flower clusters can be eaten and the young fruit can be used in soup. The fruit
has a strong smell when ripe.
Food value in 100 g edible portion:
Edible portion
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
74.5
57.6
85.8
75.5
395
600
1.5
5.6
1.6
5
30
60
6.7
10
13
0.6
0.8
0.1
0.4
Fruit raw
Seed boiled
Fruit + seed
Leaves
Flowers
300
170
Pests and diseases
Jackfruit diseases
Pink Disease
Leaf spot
Phanerochaete salmonicolor
Colletotrichum sp.
Fungus
Fungus
Insect pests
Parastasia guttulata Fairmaire
Chrysomphalus dictyospermi (Morgan)
Hemiberlesia lataniae (Signoret)
Hemiberlesia palmae (Cockerell)
Pinnaspis buxi (Bouche)
Unaspis citri (Comstock)
Icerya seychellarum (Westwood)
Anthococcus kerevatae Williams
Ceroplastes rubens Maskell
Coccus longulus (Douglas)
Milviscutulus mangiferae (Green)
Parasaissetia nigra (Nietner)
Planococcus pacificus Cox
Scarabaeidae (COL)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Margarodidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
311
Adult reported boring tunnels into fruit
White louse scale
Pink wax scale
Nigra scale
Pakal
Scientific name: Parartocarpus venenosus
What is the plant like?
This is quite a large tree up to 25 metres or more tall. It has milky sap inside. It is in the
breadfruit family.
The leaves of the tree are entire on outline and they are arranged on a spiral around the stem.
The leaves are shiny on both surfaces. The veins are raised under the leaf and sunken on
top. The leaf is lighter green underneath.
The leaf looks like this
The fruit is large and can be 14 cm to 24 cm across. It has an irregular shape. The fruit is
brown and slightly rough on the outside and with yellow flesh inside. There are quite a few large
seeds inside. The seeds are something like breadfruit. The seeds have a yellow layer over them
and are white inside.
A seed
The fruit hangs from the branches similarly to breadfruit. As the fruit get ripe they give off
as strong sweet smell. This helps people find the fruit in the bush.
How are pakal trees grown?
Often pakal trees just grow wild in the bush. Flying foxes eat the fruit and they spread the
seeds around. Small trees are sometimes transplanted nearer to houses.
Where do pakal trees grow?
Pakal trees can grow from sea level up to about 1000 metres above sea level. Mostly they
are near the sea and are more common on islands.
In Papua New Guinea they mostly occur along the North Coast and on islands off the coast.
Where did the name come from?
Pakal is a Tok Ples name from one of the
languages of Manus. It also has other Tok Ples names in
other areas of PNG, but doesn't have a common Tok Pisin
name.
The scientific name is Parartocarpus venenosus.
The word parartocarpus means near or related to the
breadfruit group of plants. Pakal or parartocarpus is a
fruit tree like breadfruit or Kapiak.
Tok ples names
Wogeo Is
Madang
Manus
New Ireland, Kalau
New Ireland, Lamekot
Rabaul
Salang
Yang
Pakal
Situ
Livu
Lapua
How are pakal used?
The yellow flesh inside the pakal fruit is eaten cooked. The flesh of the fruit is very dry and
therefore it is necessary to have a drink of water afterwards.
The seeds are poisonous at least when they are unripe. In some places the seeds are cooked
and eaten, but only after they have been soaked in seawater for a few days.
313
Candlenut
Scientific name: Aleurites moluccana
The candlenut tree
The tree is a large evergreen tree that can grow up to 40 metres tall and have a trunk which
is one metre through at the base. The bark is rough. The trees can be identified at a distance by the
pale green colour of the leaves.
The leaves, leaf stalks and flowers are all covered with short soft hairs. The leaves are large
and can be round, triangular or have several lobes. Leaves of young trees are often a different
shape from mature leaves on older trees. Two distinct brown glands occur where the leaf blade
joins the stalk. The leaf stalk is long.
The flowers are small and white and in large groups on the ends of branches. Male and
female flowers are separate but on the same tree. The female flowers are on the end surrounded by
small male flowers.
The fruit are 4 to 5 cm across and green with one or two seeds inside. They do not open
naturally to release the seeds.
The seeds or nuts are in a very hard shell. As well, the kernels do not easily come free from
the shell and often they must be dug out. The outside of the shell is rough.
How do you grow candlenuts?
Candlenut seeds have a very hard shell. If the seeds are just planted it may take many
months for this hard shell to break down and the seed to start growing. So a special way of
preparing the seeds is required. A single layer of seeds is put on the ground. Then some dry kunai
grass is spread over the top. The kunai grass is burnt and then while the seeds are still hot they are
dropped into cold water. This cracks the shells so that when the seeds are planted they will grow
more quickly.
Often candlenut trees are just self-sown, growing in the bush where the seeds fell. These
small trees can be transplanted to a more suitable place if needed.
Where do candlenuts grow?
Candlenuts grow better in a drier climate. In Papua New Guinea they are quite common in
areas like the Eastern Highlands, Bulolo and in the Western Province. They are most commonly on
well-drained sandy soils.
The trees can be grown from sea level up to about 2000 metres altitude, but are more
common in the lowlands.
Candlenut trees are common in Pacific Islands Countries, Papua New Guinea, Indonesia and
Malaysia and as far as India. They have also been taken to other countries.
Candlenuts as food
The raw kernels of candlenut are poisonous. They are a strong purgative. Before eating
they must be well cooked.
Mostly the nuts are roasted in the fire until the shell is blackened and half burnt, then the
kernels are taken out by cracking the shells.
The nuts should probably only be eaten in moderate amounts.
Because the kernels are high in oil, they can be burnt as candles. Also the black soot from the burnt
seeds is used as a black paint for faces.
Food value:
When the seeds are dry they are high in both energy and protein. A 100 g sample contains:
Edible portion
Moisture
%
Energy
KJ
Protein
%
Kernel
Kernel treated
Kernel cooked
24.4
12.8
1.4
2426
1400
2836
7.8
0.5
20.6
ProVit A
µg
Provit C
mg
Pests and disease
A leaf spot probably due to a fungus can be seen on candlenut tree leaves.
Insect pests
Chrysomphalus aonidum (Linnaeus)
Hemiberlesia lataniae (Signoret)
Hemiberlesia palmae (Cockerell)
Pinnaspis strachani (Cooley)
Coccus longulus (Douglas)
Eucalymnatus tessellatus (Signoret)
Dysmicoccus nesophilus Williams
Planococcus pacificus Cox
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Diaspididae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
Coccidae (HEM)
315
Florida red scale
Iron
mg
Zinc
mg
2.7
2.7
22.6
3.2
Castanopsis chestnuts
Scientific name: Castanopsis acuminatissima
Tok Pisin: no name
Tok Ples names:
Huli
Pai
Wiru
Ka wongo
Mendi
Pole
Pe
Pai
Foi
Bai
The Castanopsis chestnut tree
This tree grows up to 40 metres tall and it can have a trunk 1 metre through at the base.
Most trees have several suckers growing from their base and the roots of the tree are close to the
surface.
The male and female flowers occur separately but they both occur on the one tree.
The tree has flushes of growth with new leaves having a slightly reddish colour.
The nut has a spiky type of covering around it and as it ripens this peels back and the nut
falls. The nut is pointed, brown and slightly hairy. It is about 1.5 cm long and has two large
"seeds" inside.
Where do these chestnut trees grow?
They grow throughout Papua New Guinea. The most common place is between 1100 and
2300 metres above sea level but they can occur down to 500 metres in many places and are at the
sea level in the South Coast of New Britain. Some people have suggested that they grow down as
far as the afternoon clouds commonly come down.
Often these chestnut trees are more common on the boundary between the grassland and the
forest. They form a thick covering of leaves that stops many smaller plants from growing
underneath. As well they commonly grow in groups or clumps made up only of chestnut trees.
From aeroplanes, these Castanopsis forests can be picked out because they have a distinctive
yellowish brown colour. Under the trees there is usually a thick layer of fallen leaves.
Growing Castanopsis chestnuts
The seeds grow easily. Self-sown plants can often be found under large trees. These can be
transplanted to where you want to grow a tree. Or you can set up your own nursery by planting
some seeds and then transplanting them when they are big enough.
Although suckers are common near the base of trees they do not grow easily.
The chestnuts
A nut is quite small. One nut weighs about 1 gm and the
edible seed inside weighs about 0.5 g.
Small numbers of the nuts are eaten raw by children.
Mostly the nuts are cooked and eaten. If small amounts are available they are boiled in a
container. If large quantities are available they are mumued. Cooked they taste like rice.
Cases have been reported of mouth ulcers and anaemia after people have eaten a lot of raw
nuts. It is therefore safest to cook them.
Pigs like the nuts very much and in some areas such as Pangia people take their pigs out and
tie them up under the trees in the bush during the nut season.
The tree as timber
Foresters call the tree Papua New Guinea oak because it is in the oak family and the timber
looks like oak. It is a very valuable timber. The timber is hard and posts last a long time. People
like it for house posts. The bark is used for walls, for insulation.
317
Coconut
The coconut palm
The coconut palm is one of the most familiar plants in the coastal regions of Papua New
Guinea and the tropics. A common saying is that coconuts will not grow if they are out of sight of
the sea, but they will grow reasonably well up to about 300 metres altitude.
The palm grows up to 30 metres tall and is normally unbranched. The trunk often curves
towards the sunlight. They do not do well in shady and overcast areas. Coconuts in Southern
Bougainville yield only very poorly because it is wet and cloudy. But coconuts also do not do well
in areas with a long dry season unless they have underground water.
Coconuts need a moist atmosphere and a moderate temperature between 27°C and 32°C and
a loose well-drained soil. These conditions are normally met near the coast. Coconuts do not
require a salty soil but can tolerate some salt.
The flower stalk grows from the axil of the leaves and has both male and female flowers
separately on the stalk. There are 20 to 40 female flowers near the base of each branch and 200 to
300 male flowers on the upper parts of each branch. Because the male flowers shed their pollen
before the female flowers are open, plants are normally cross-pollinated. Wind and insects spread
the pollen between palms. About 6 nuts mature on each flower stalk so that a palm produces 60 to
70 fruit each year. The green skin becomes yellow as the fruit ripen.
When the coconut is mature it is about 30 cm across and weighs about 2 kg. The nut inside is
about 10-15 cm across and weighs 1.5 kg. The centre of the nut contains about 0.5 litres of sap
called the coconut water. This is sweet and slightly aerated and makes a very refreshing drink. The
white layer around the seed inside the nut grows and hardens and as a nut germinates an "apple"
forms inside. These can both be eaten. The dried white layer is copra that is removed, dried and
sold.
Planting coconuts
It takes about 4 months for the shoot to appear. Young coconut seedlings go on feeding from
the nut for a few months during their early growth. The trees need to be planted in a sunny place.
They can be put in a nursery and transplanted after 6 to 12 months. Early sprouting nuts normally
make the best plants.
Palms start producing nuts after about 6 to 7 years although the dwarf kinds produce earlier
as do some of the newer varieties.
319
Pest and disease
Coconut diseases
Sooty mould
Fungi
Stem bleeding
Black leaf mould
Fungus
Fungi
and
Fungus
Fungi
and
White thread blight
Leaf spots
Root rot
Brown root rot
Bud rot
Fungus
and
Fungus
Fungus
Capnodium sp
Chaetothyrium sp
Meliola sp
Ceratocystis paradoxa
Clasterosporium cocoicola
Sporidesmium macrurum
Corticium penicillatum
Bipolaris incurvata
Pestalotiopsis palmarum
Pseudoepicoccum cocos
Ganoderma lucidum
Rigidoporus microporus
Phellinus noxius
Phytophthora palmivora
Basal stem rot coconut (Also called Butt rot and Ganoderma wilt)
It is due to a fungus Ganoderma lucidum. When coconuts get this disease the new fronds fail to open and the palm
looks wilted and paler green. The older fronds then wilt and die from the tips. At the base of the palm dead spots occur
with dead roots. Near the dead spot there is a bright yellow zone. The white fungal threads are visible. Bracket fungal
bodies develop. The top of these has zones and a shiny appearance. Underneath is soft. The disease gets worse in dry
weather because this allows the wilting to get worse. Poor drainage, heavy weed growth and poor soil fertility possibly
help a little in the disease attack. The fungus is common on rotting trees. It can attack old coconut stumps. When new
palms are planted near these the fungus spreads via the roots. Often the new palm does not show damage for 10-15
years. This type of fungus is common in forests on old rotting trees. Affected palms can die in 6 -12 months. It can
also affect oil palm and other rotting tree stumps.
Control is by getting rid of all likely infected stumps before re-planting old plantations.
Brown root rot of coconut. This is due to the fungus Phellinus noxius. When coconuts get this disease, dead spots
develop on the trunk. The trunk collapses. Sometimes before this occurs the leaves may turn yellow, wilt and hang
down. The spots on the trunk are dark brown with dark brown zones. It mostly attacks palms over 10 years old. Palms
in poor soil conditions especially low potassium get the disease more. The disease spreads by the fungal spores
blowing in the wind. The disease takes 1 to 3 years before the palm is killed. It also attacks oil palm. It can attack
avocado, cacao, coffee, rubber, kapok, mandarin, mangosteen, rambutan and other trees.
Control is by cutting out spots that need to be found early and then cut out. The area needs to then be treated with coal
tar. Dead palms should be removed.
Bud rot coconut is due to the fungus Phytophthora palmivora (Butler) Butler
With this disease spots develop especially on young nuts and at the stalk end. It occurs in warm areas with a high
rainfall. The fungus often occurs around the roots of coconuts and may spread from here. The disease mostly starts
following damage to the young nuts. Nuts fall off early. The fungus also attacks cacao (Black pod), rubber (black
stripe), pawpaw (fruit rot) and over 135 other plants.
Drechslera leaf spot of coconut is due to the fungus Bipolaris incurvata of which the asexual form is Drechslera
incurvata. With this disease small spots develop on young coconuts. The spots are oval and brown but get larger and
turn pale in the centre. The edges of the leaves can become dead. It gets worse when young coconuts are overcrowded
or in heavy shade or have poor soil fertility. Heavy nitrogen fertiliser increases the amount of disease. It gets worse
when there is dew on the leaves. The spores of the fungus blow in the wind.
Control is by increasing the spacing of plants, improving the soil fertility, making the nursery less shaded, fertilising
young plants with potassium and phosphorus fertilisers and using shade cloth to reduce dew.
Grey leaf spot coconut. This disease is due to the fungus Pestalotiopsis palmarum. It causes small yellow brown
spots to develop on the leaves. These become white to grey and have a brown edge. The spots are oval and about 1 cm
long. It gets worse under poor growing conditions. This includes wet conditions, planting close together and where
there is heavy shade. It often follows attack by insects. It gets worse with poor soil fertility. The fungus spores blow in
the wind then grow and penetrate the upper surface of the leaf. It is mostly a problem of seedling coconuts. It also gets
on Betel nut and Oil palm.
Control is not normally necessary. The disease is reduced by spacing seedlings more widely, using sprays of chemical
fungicides eg Bordeaux or Zineb, using potassium fertiliser, and adding of sea water (200-1000 ml) and seaweed salt
(20-100 g) to bagged seedlings to reduce the disease.
Stem bleeding of coconut can be due to a fungus Ceratocystis paradoxa of which the asexual stage is Thielaviopsis
paradoxa. But stem bleeding can have other causes. With this disease a rusty brown discolouration of the bark occurs.
The disease produces a characteristic smell. The fungus has a resting stage in its cycle that allows it to survive longer
when conditions are not suitable. The fungus grows well between temperatures of 25°-32°C. The fungus occurs very
widely. It is spread through soil and plant remains. It causes pineapple disease of sugarcane. The fungus can attack
pineapples, bananas, betel nut palms, oil palm, sweet potato, sorghum, cacao and corn. Control is by avoiding
damaging the trunks of coconuts.
Coconut insect pests
Sap sucking bugs
Green coconut bug Amblypelta cocophaga and Papuan tip wilt bug Amblypelta lutescens
papuensis. The adults are greenish brown with smoky wings and 20 mm long. They suck
sap and secrete a toxic layer that causes plants to wilt and fruit to drop. The damage is
probably worse when coconuts are in the bush as these insects live on other bush plants.
Coconut spathe bug Axiagastus cambelli. These insects are dark brown with yellow
marks and 13 mm long by 7 mm wide. They give off a bad smell when disturbed. They
feed on the male flowers of coconuts causing them to turn brown but nuts do not normally
fall. It is mostly on the islands. It is controlled by other insects.
Coconut white fly Aleurodicus destructor. This insect produces long coiled wax threads
that form a woolly covering on the underside of infected leaves. The damage is probably
slight but nuts can fall early.
Coconut leafhopper Zophiuma lobulata. This lophopid treehopper or bug injects a toxin
and can cause serious nut fall of coconuts in the Finschhafen and Popondetta areas. It has
egg parasites that help control the pest. Adults and nymphs are present on palms.
Scales and mealy bugs
Coconut scale Aspidiotus destructor. This yellow insect has a clear round scale over its
body which makes it look like bumps on the leaves. They tend to be along the veins on the
undersurface of the leaves and they suck sap. The leaves turn yellow. Damage can be bad
until suitable predators are introduced into an area.
Soft brown scale Coccus hesperidium. These flat brown scale insects are about 3-4 mm
across and occur on a number of trees. These insects tend to cause sooty moulds to grow
on the secretions from the insect.
Florida red scale Chrysomphalus aonidum.
Pineapple mealy bug Dysmicoccus brevipes.
Pink wax scale Ceroplastes rubens.
FRS
Moths and butterflies
Banana skipper Erionota thrax. The larvae of this case building caterpillar chew the
edges of leaves then use them to builds its case. Drought probably helps outbreaks of this
pest and damage can occur in the Markhum Valley. It also attacks bananas.
Coconut cup moth Thosea sinensis. The larvae of this moth cause extensive damage to
young coconuts in the Central Province. The larvae are green or grey with a stripe along
the back and coloured spots on the side.
Coconut spathe moth Tirathaba rufivena &Tirathaba ignevena. These small light brown
coloured moths have larvae that feed on newly opened coconut buds. They cause nuts to
fall. The larvae bore into male flowers causing them to become webbed together. Some
parasites and predators help control. Populations of crazy ants can make the nut fall more
serious.
Lesser Coconut spike moth Batrachedra arenosella. The larvae chew male and female
flowers and can cause slight damage.
321
Coconut skipper Cephrenes mosleyi.
Beetles and weevils
Asiatic rhinoceros beetle Oryctes rhinoceros is about 35 to 50 mm long and the adult male
has a horn that curves backwards. They mostly fly at night to the crowns of palms. The
creamy white curl grub is 60 mm long and the whole life cycle for the insect takes 5 to 9
months. These beetles also attack pandanus, sago nipa and oil palms as well as bananas.
They can kill young palms by boring into the crown of the palm. But they also allow the
palm weevil to get access to the palm through the hole they make. The insect only occurs
on the islands, but is bad in the Gazelle peninsula. The main control is by getting rid of
breeding places. The beetles can be collected and killed. A virus disease has been
introduced to help control this pest.
Cane weevil borer Rhabdoscelus obscurus is mainly a pest of sugarcane but can bore into
coconut palms.
Coconut bole weevil Sparganobasis subcruciatus attacks the lower parts of coconut palms
and palms eventually fall over. They lay their eggs in the trunk of the palm about 25 cm
from the ground.
Coconut hispids Brontispa longissima; Brontispa palmivora and Brontispa simmondsi,
are small orange and black beetles 10 mm long and 4 mm wide. They lay their eggs
between tightly folded young leaves and the larvae feed inside these leaves. They can
severely damage young coconut palms. The adult chews narrow stripes in the leaf. The
main problem is in nurseries.
Coconut leaf miner Promecotheca papuana is a golden brown colour with a blue tip. It is
about 8 mm long and the insect passes its life cycle in the crown of coconuts. It is normally
only a problem on Manus and New Britain where the adults chew the leaves of mature
palms. It can take a palm up to 2 years to begin producing nuts again. Some other insects
including kurukum ants help control.
Elephant beetle Dynastes gideon. This insect is distinctive because of the long horn on the
male. They live on the underneath surface of the coconut frond and damage young leaves.
Island pinhole borer Xyleborus exiguus; Xyleborus perforans, coconut shot-hole borer.
These bark beetles damage the trunk and allow other diseases and insects to get into the
trunks. The adult beetles are small about 2 mm long and reddish.
Lesser coconut borer Diocalandra taitense. The larvae of this weevil can cause some
damage to coconuts but mostly only where other insect damage has already occurred.
[Possibly also Diocalandra frumenti (F.)]
New Guinea Rhinoceros beetle Scapanes australis grossepunctatus and Scapanes
australis australis. These are large beetles with a horn of their heads. Males have two
horns on the thorax. These beetles occur on the coast and up to about 900 metres altitude.
The adults attack young coconut palms and they can kill the palms. They are controlled by
removing the adults by hand removing decaying logs that are the breeding sites and by
growing cover crops through the plantation.
Palm weevils Rhynchophorus bilineatus - black palm weevil & Rhynchophorus
ferrugineous - red palm weevil. The adult weevils are about 40 mm long with a long snout.
They fly in the morning and evening making a buzzing sound. They are probably the most
damaging pests of young coconuts. They gain entry into the palm through cuts or damage
by other insects. They can also attack young leaves causing them to drop off. To control
them it is important to avoid damaging coconut palms and to seal off damage holes. Fronds
should be cut off, not pulled off.
Taro beetles Papuana spp. These beetles are common in taro gardens. They are about 15
to 25 mm long and the white curl grubs feed on plant roots. These beetles can dig well and
damage the roots of young palms. They are hard to control.
Other beetles and weevils
Ischiosopha ignatipennis Boisd.
Cetoniidae (COL)
Lophotectes penicilliger (Heller)
Curculionidae (COL)
Meredolus cocotis Marshall
Curculionidae (COL)
Oryctes centaurus Sternb
Scarabaeidae (COL)
Reported damaging coconuts.
Pseudoligota sp
Staphylinidae (COL)
On male flower of betel nut palm. On male flower coconut.
Trichogomphus excavatus Mohinke
Scarabaeidae (COL)
Moderate damage to coconut fronds.
Trichogomphus semmelinki Rits
Scarabaeidae (COL)
Rhinoceros beetle
Reported damaging coconuts.
Grasshoppers
Coconut tree-hoppers Eumossula gracilis and Segestidea spp.
These longhorn
grasshoppers damage the leaves and crowns of coconuts especially where there is no long
dry season. The green tree ant is a deterrent, and some other insects also attack these pests.
Oxya japonica (Thnb.)
Acrididae (ORTH)
Also occur on rice, maize, coconuts, cacao, coffee and cotton.
Psammoecus sp.
In old coconut leaf mine.
Silvanidae (COL)
Termites
Microtermes biroi Desneaux
Rhinotermitidae (ISOP)
Building runways on trunk coconuts. See DAL Entomology Bulletin No 47
323
Galip nuts
Scientific name: Canarium indicum
Names
In Tok Pisin the word "galip" can be used in several different ways. It has both a general
and then also a specific meaning. It can be used very widely to include many nuts such as peanuts,
pao nuts, and several other nuts from trees. As the word "galip" was originally a Tolai word from
the Kuanua language this is the way it is being used in this article. Tolais used "galip" for the nuts
of a particular tree that is also called the Canarium almond in English.
Scientists give every plant a scientific name in the Latin language, then it is the same for all
scientists of the world, no matter what language they speak. The name scientists have given to this
plant is Canarium indicum. It was given this name by a man called Linnaeus as long ago as 1759.
Unfortunately early scientists mixed up two similar nut trees and so the scientific names have also
got mixed up and are often used incorrectly. The correct name for the common galip in Papua New
Guinea is Canarium indicum L. A similar, but different, nut tree grown in Malaysia and in Pacific
Island countries such as Fiji, is called Canarium vulgare Leenhauts. A name that has been used
incorrectly for both these plants is Canarium commune L and this name should no longer be used.
The way to tell the difference between these 2 plants is
by looking at a leafy type of growth (called a stipule) that occurs
near where the leaf stalk joins the branch. In the PNG galip
(Canarium indicum) this leafy part stays on the stalk and around
the edge of it, there are teeth like a saw. In the Pacific tree
(Canarium vulgare) this leafy stipule has a smooth edge and
also tends to drop off the tree quickly.
Within the Canarium genus or group, there are several different plant species that produce
edible nuts. The ones that occur in Papua New Guinea and have nuts that are eaten are listed below.
Canarium indicum L - Common galip or galip tru
Canarium solomonense Burtt
Canarium kaniense Laut
Canarium schlechteri Laut.
There is also probably a species in the Western Province of which the flesh is eaten, after
cooking, like the Chinese olives (Canarium album).
It is interesting that such a large and important group of food plants has not been studied and
improved by agriculturalists.
This group of plants called Canarium were given this part of their name after a Malayan
word "kanari" which was used for these plants. There are about 100 different species of plants
belonging to this group called Canarium. All of these plants originally occurred only in a few
countries of the world, mostly in the Asia and Pacific area.
The area is shown on this map drawn by a botanist called Leenhauts who has made a
special study of these plants. A few of these plants also occur in Africa.
Map showing where Canarium nuts occur
The next table is of the different scientific names of the edible Canarium plants known from
other countries.
Canarium album Raeusch
Canarium australasicum
Canarium decumanum Gaertn.
Canarium grandiflorum Benn
Canarium luzonicum A Gray
Canarium muelleri
Canarium nitidum Benn
Canarium oleosum (Lamk.) Engl.
Canarium patentinervium Miqu.
Canarium pseudo-decumanum Hochr.
Canarium rufum Benn.
Canarium schweinfurthii Engl.
Canarium strictum Roxb.
Canarium vulgare Leenh.
Canarium zeylanicum Blume
Canarium amboinensis Hochr.
Canarium bengalense Roxb.
Canarium denticulatum Blume
Canarium littorale Blume
Canarium megalanthum Merr.
Canarium nigrum Engl.
Canarium odontophyllum Miqu.
Canarium ovatum Engl.
Canarium polyphyllum K.Schum.
Canarium purpurascens Benn.
Canarium samoense Engl.
Canarium secundum Benn
Canarium sylvestris Gaertn.
Canarium williamsii C.B.Rob.
Canarium harveyi
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What is a galip nut tree like?
It is a large tree often up to 40 m high. The stems are often twisted or rough and there are
usually buttresses at the base of the tree.
The small branches are more or less powdery. If a small branch is cut crossways and looked
at very carefully, small round vascular strands can be seen in the pith or centre mass of cells. (This
is different to most woody trees where these are in a more or less continuous circle around the edge
of the branch).
The leaf of a galip tree is made up of 3 to 7 pairs of leaflets. The leaves do not have hairs on
them. The leaflets are oblong and can be 7 to 28 cm long and 3 to 11 cm wide.
At the base of a leaf where the stalk joins the branch there is a special leaf like structure that
is important for helping to identify the PNG galip tree. This leafy structure is called a stipule and it
is large and has saw like teeth around the edge. (Another PNG Canarium nut (Canarium kaniense)
also has a similar large stipule.)
The flowers are mostly produced at the end of the branches. A group of flowers are
produced on the one stalk. The flowers are separately male and female. The male flowers have 6
anthers or pollen containers in a ring. In the female flower these 6 stamens are improperly
developed (staminodes) around a 3-celled ovary.
The galip fruit has 3 cells (sometimes 4) but mostly only one cell is fertile so that 2 of the
cells are empty, and one has a kernel.
Where do galip nuts grow?
The galip (Canarium indicum) grows in coastal areas, and is most common in the islands
such as North Solomons Province, New Britain and New Ireland. It also occurs naturally in the
Solomon Islands, Vanuatu and Guam. It occurs on the New Guinea mainland and Irian Jaya as well
as in Maluku in Indonesia. It has been taken to some other countries to grow.
Galip nuts are common in the lowland rainforest.
They mostly grow from sea level up to about 300 m altitude.
How do you grow galip nut trees?
Many of the galip nuts take several months for the seeds to start to grow. As well, the seeds
normally should not be buried under the ground, but should be just near the surface of the ground.
Care is needed to see that the seeds and seedlings do not dry out.
As the seed grows or germinates, a well-defined cap is split off the nut.
Trees grow fairly quickly.
Varieties of galip nuts?
Not all galip nuts are the same. People on the St Matthias group of islands off New Ireland
recognise 7 different kinds. These include the most common pale coloured galip but also one with
a reddish black seed, one with a larger kernel, one with a small kernel, one with a round fruit and
one with a thin walled nut. This sort of variation is important for plant breeders who want to
improve the kinds that are grown.
Pest and disease
Disease
Heart rot
Phellinus noxius
Fungus
Insect pests of Galip
Ectatorhinus magicus Gerstaecker
Pinnaspis buxi (Bouche)
Coccus hesperidium Linnaeus
Planococcus pacificus Cox
Pseudococcus solomonensis Williams
Curculionidae (COL)
Diaspididae (HEM)
Coccidae (HEM)
Pseudococcidae (HEM)
Pseudococcidae (HEM)
327
Weevil boring into trunk of galip
Mealy bug
Mealy bug
Finschia nuts
Scientific names:
Finschia chloroxantha
Finschia ferruginiflora
Finschia rufa
The tree and nuts
These three different nut trees occur in the several areas of Papua New Guinea with
especially Finschia ferruginiflora near Kainantu but the others are important in several areas. They
are related to the more famous macadamia nuts that have been introduced and are now being grown
in some areas of Papua New Guinea.
The trees can be up to 24 metres tall and often they have buttresses near the base and they
can have stilt roots. In many areas the trees grow naturally in the forest, but in some areas the trees
are planted and the nuts regarded more importantly.
The leaves are often clustered near the ends of branches so that the tree does not have a
dense covering of leaves. The leaves can be 25 cm by 10 cm in size and have a vein around the
edge joining the other leaf veins. The flowers occur is a long cluster up to 30 cm long and are
bright orange in colour. They hang below the leaves and on the older wood. The flowers have both
male and female parts in the same flower. The fruit are round and 2.5 cm by 3 cm across and
brown. They have a sharp point on one side. The outside of the fruit is soft but there is a hard shell
inside with one large edible seed.
The trees occur from the lowlands up to about 1800 metres altitude and can occur in swamp
forest but not where the soil is covered with water. Because this tree is regarded as a valuable nut
the tree is rarely cut down but the timber is a good hard and attractive timber.
The nuts have a very hard shell but this is removed by cooking. The kernel of the nut is then
removed and eaten. This nut is used in Vanuatu, Solomon Islands and Papua New Guinea as well
as in Micronesia. Trees flower from December to March and nuts are available from March to
August.
Finschia
ferruginiflora
Tree
30 m
Finschia
chloroxantha
5-25 m tall
Finschia rufa
15-18 m tall
Leaves
18 x 5 cm
smooth
40 x 12 cm
smooth
30 x 12 cm
Flowers
Brown
Very hairy
Orange-yellow
Almost smooth
Yellow-brown
Reddish & hairy
40 cm long
Fruit
5 cm round
4 cm flat on one
side
Names.
These trees have been given several different scientific names during the time scientists
were getting to know them and work out how they are related to other trees. These names include:
For Finschia chloroxantha
Helicia micronesica Kanehira
Finschia micronesica (Kanehira) Kanehira
Grevillea densiflora C T White
Finschia densiflora White
Finschia elaeocarpifolia Gillaum
Grevillea micronesica Sleum
and others
The confusion over names comes from the fact that these trees have flowers like Grevillea
trees and fruit like Helicia trees.
These trees are in the plant family Proteaceae and most of the trees in this family occur in
Australia and South Africa. Very commonly the trees will grow well in hot dry climates.
Pest and disease
These have not really been studied for these nuts. It is not known if the pest and diseases
that damage macadamia nuts also damage these trees.
Diseases
Black mould
Rust
Black leaf mould
Chaetothyrium fusisporium
Puccinia finschiae
Stenella sp.
Fungus
Fungus
Fungus
329
Karuka or pandanus family
Karuka
Pandanus jiulianettii
Wild karuka
Pandanus brosimos
Pandanus antaresensis
Pandanus conicus
Coastal pandanus
Pandanus tectorius
Marita
Pandanus conoideus
Karuka
Tok Pisin: Karuka
Scientific name: Pandanus jiulianettii
Two species of pandanus are commonly used for the nuts that are eaten. They are karuka
(Pandanus jiulianettii Martelli) and wild karuka (Pandanus brosimos Merr & Perry). At least 3
other species of pandanus are used occasionally in Papua New Guinea for edible nuts and marita
pandanus is used for the long red fruits. The leaves of many other pandanus species are used for
rain capes, sleeping mats, canoe sails etc.
This article is about cultivated karuka.
The karuka plant
The karuka tree is a tall palm like tree with a straight trunk and aerial prop roots at the base.
Sometimes it branches near the top to produce 3 or 4 crowns of leaves.
The leaves grow in pairs opposite each other and they are twisted to look like a spiral going
up the trunk. The leaves are long (3 m), narrow, have spikes along the edges and are often bent at
the tips.
The fruit is a round composite fruit 15 to 30 cm across which is made up of about 1,000
individual keys which contain the nut which is eaten.
Karuka trees have male and female flowers separately on separate trees. Male trees produce
a white flower but no fruit. They are not very common.
331
Where does karuka grow?
Karuka grows in several highland provinces of Papua New Guinea. It mainly grows at
altitudes between 1800 metres and 2500 metres above sea level. Outside this range it often does not
grow well.
Karuka is only grown in Papua New Guinea.
Within these areas, karuka has a special place where it grows best. Karuka needs fairly
good soil fertility so it does best along the banks of small creeks, in the natural hollows that occur
around the edges of hills, and around the edges of small clearings in the bush. Lots of karuka are
seen out on knobs in the grassland but often these only bear small nuts.
Some areas produce good karukas, while karuka grows poorly in other places. In some
places karukas are grown in lines as boundary markers between garden plots.
The karuka fruit and nut
One crown of leaves on the one branch of a karuka tree normally only produces one cluster
of nuts (called a syncarp) during the one season. In fact, that particular branch normally only
produces one bunch every second year.
On a branch that is about to bear fruit, the leaves are upright and clumped slightly together.
The fruit bunch emerges from the centre of these leaves. It hangs close to the trunk amongst the
dead hanging leaves. Large leaves (bracts) almost cover the fruit bunch while it hangs there.
A fruit bunch hanging down
from between the leaves and
covered by dry brown leaves.
While the fruit is being produced, the tree stops producing new leaves. A new sprout of
leaves eventually shoots up in the centre of the clump and this is normally taken as a sign that the
nuts are ready to harvest. The whole bunch is normally cut down with a bush knife. Often the tree
has to be climbed to do this.
A fruit cut in half
a whole fruit
The outside layer of the fruit is burnt off, in a fire. This allows the bristly ends of the
individual keys to be seen.
A portion of the surface
after the skin has been
burnt off
The honeycomb
looking spongy
central portion
that can be eaten.
In the centre of the bunch is the stalk. This is
surrounded by a spongy type material into which the
ends of the individual nuts are inserted. This spongy
layer (the mesocarp) has an appearance like
honeycomb, when it is separated from the nuts. It can
be cooked and eaten.
333
The individual keys or nuts can then be separated and broken open to get out the kernel that
is eaten.
A single shell and kernel looks like this:
How do you plant karuka?
There are some different ways of planting karuka.
One of the common ways is to cut the top section off one branch of a mature tree that has
several branches. When planted in moist fertile soil it quickly develops roots and becomes
established. This method has two advantages. You can be sure that the new tree will be exactly the
same as the old one because it is vegetative propagation. Also old trees with a number of branches
tend to have smaller clusters of fruit because the fruit are competing on the same plant for their
requirements.
Sometimes karukas develop young suckers or shoots near the ground. When these are seen,
they are broken off and replanted.
Karuka can be grown from seeds. It is best to wait till the nuts are fully ripe and start falling
naturally from the tree. These nuts are taken and planted while fresh. They are planted in the shell
with the bristles uppermost.
Normally the seeds are established in a nursery and then transplanted to their permanent
sites a few months later. Karukas can start to produce nuts 5 or 6 years after planting. They can
keep producing for probably 50 years.
To produce good-sized nuts the karuka plantation needs to be kept free of weeds.
Varieties
There are many varieties of karuka. Up to 20 varieties are maintained by some growers.
One farmer near Paip in the Mendi Valley knew 35 varieties.
One of the most noticeable things that varies is the shape of the nut and kernel. Two kinds
are drawn below.
Nut
kernel
Nut
kernel
Most varieties are roasted before eating but one or two varieties are eaten uncooked. All
varieties can be mumued. All varieties can be smoked and stored.
All varieties tend to fruit at the same time but some kinds get ready to harvest more quickly
than others.
Varieties differ in their height, number of branches, thickness of the shell of the nut, and a
little bit in their general appearance and colour of leaves and bark.
Pests and Diseases
Karuka have some pest and disease problems.
At least 4 different kinds of fungal diseases can be seen damaging the leaves. There is a
sooty mould that makes irregular black patches over the surface of the leaf. It is really only
growing on the rubbish left on the leaf surface by small insects. Another black leaf mould grows in
thin straight streaks along the middle of the leaves. It only seems to grow on some varieties and
village people seem to use it as one indicator to help them recognise the different varieties. These
two diseases probably do not cause too much trouble.
There are also two yellowish leaf spots, one clear and sharp and the other faint and irregular
that can commonly be seen on the leaves. They seem to vary both with variety and time of the year.
One of the serious insect pests of karuka are longhorn grasshoppers.
A longhorn grasshopper
These grasshoppers climb the trees and chew the leaves. Damage can be severe and by
eating out the growing point of the tree they can actually kill the tree. Similar longhorn
grasshoppers damage coconuts on the coast.
Village people try to reduce the damage by pushing grass and leaves in between the leaves
near the crown to stop the insects getting in.
The grasshoppers lay eggs in the grass and rubbish near the base of the tree. In coconut
plantations clearing around the bottom of the tree then spraying, is used. Control of these insects in
karuka has not been studied.
335
A large black grub also damages karuka by burrowing into the bunch of fruit and causing it
to fall before the bunch is ripe. It eats the spongy layer and the fruit goes black outside.
Occasionally wood boring grubs burrow into the aerial prop roots of karuka.
A fungal disease has also been recorded growing on karuka nuts.
Diseases
Black leaf mould
Sooty mould
Leaf spot
Diffuse leaf spot
Fungus on seeds
Lembosia pandani (Rostr.) Thiess
Meliola juttingii Hansf.
Fungus
Fungus
Macrophoma pandani Berk & Vogl
Insects
Longhorn grasshoppers
Cockroaches
Caterpillar
Wood borer
Segetes gracilis
Segistidea montana
Periplanata americana (L.)
Possums are another problem with karuka. People build platforms up the trunk of the tree to
stop possums climbing up.
A framework to stop possums
For karuka nuts stored in houses, rats and cockroaches are the two main problems. These
can be controlled by hanging the nuts in the smoky areas above the fire. But if nuts are left too long
in this position they start to develop a smoky taste that is not liked.
Storing and using karuka.
Karuka nuts can be harvested before they are fully ripe by climbing the tree and cutting the
whole bunch. When this is done, the fruit bunch is cut in half the central pink portion cooked and
eaten and the two halves with the outside skin burnt off can be stored in a platform above the fire.
These halves can be mumued with hot stones and the nuts eaten.
Two varieties at least can be eaten fresh without cooking.
The whole fruit bunch can, if desired be stored in damp waterlogged ground for a few
months if there are too many fruit to use at the one time. These fruit are collected again and cooked
and used as if they had just been harvested.
Particularly for nuts harvested ripe there are two ways to use them. They can be eaten fresh
after cooking. Or they can be dried and stored and eaten later without cooking. When the nuts are
harvested ripe the individual nuts are pulled out from the central honeycomb looking spongy
material. This central piece can be boiled if only a few are available, or mumued if a lot are
available. It is then eaten. The individual nuts can be roasted by tying them along a stick and
holding them over a fire. If they are to be stored they are sun dried. To dry the nuts they are put
out daily in the sun and taken into the house at night. After they are dry they can either be stored in
the shell for about 6 months or if it is wanted to store them for 1 or 2 years, they are normally
shelled and only the kernels stored. These can be stored by filling up a bamboo, or by making a
container of leaves.
Sometimes karuka nuts that have been harvested ripe are stored for up to 6 months by
putting the individual nuts in the ground, separated and surrounded by soil. When they are taken
out they taste like fresh nuts.
Karuka as food
In 100 g of the part eaten there are the following amounts of different nutrients.
Moisture
Energy
Protein
Calcium
Iron
proVitA
%
cals
g
mg
mg
!g
Kernels
9
540-700
11.9-14.1
419
Centre
8.5 dry wt
provitC
mg
This means karuka are good quality food.
Amount of food produced
An average karuka fruit can be about 6 kg weight. It is about 25 cm high and 20 cm across.
It contains about 1000 separate nuts. After burning off the outside and removing the stalk, the
weight is about 5 kg. A single kernel weighs about 0.5 g. The weight of edible kernels in a fruit is
about 8% of the total fresh weight or about 0.5 kg.
Season
Karuka is seasonal. The season is often about February but it may vary from December to
May. Sometimes there is a second small season about July. Often trees only bear a good crop
every second year. Normally any individual branch of a tree only has a bunch of fruit every second
year. If it does have two bunches two years in a row, the bunches are usually small.
337
Wild karuka
Tok Pisin: Karuka
Scientific name: Pandanus brosimos
The wild Karuka plant
The wild karuka plant looks a lot like the cultivated karuka. The leaves are bigger and
normally they point straight up instead of bending over at the top.
The trunk of the tree is straight like a palm but it can have some branches near the top.
The leaves are long and have thorns along the edge. Dead leaves normally hand down around the
top of the tree.
The fruit is a round cluster of nuts. The ends of the individual nuts come to a sharper
point than in cultivated karuka. The shell of the nuts is very hard.
Different varieties of wild karuka are recognised. These have different shaped nuts.
Other small differences are also noticed by village growers.
Sometimes another pandanus that grows in grasslands and bush in the highlands is also
called wild karuka. This pandanus has much larger individual nuts. It has the scientific name
Pandanus antaresensis and is described in a separate article.
Where does wild karuka grow?
Wild karuka (and cultivated karuka) only grows in Papua New Guinea. Wild karuka only
grows in the high mountain areas although sometimes people transplant an occasional tree down to
lower places where they have their gardens.
It grows between 2500 and 3100 metres altitude above sea level.
In the Southern Highland Province wild karuka can be seen growing beside the roads that
go to Tambul, Kandep and through the Tari gap. It is also in the bush in other high mountain bush
places but you have to walk in to see it.
Often plants are just scattered singly through the bush.
Who owns the wild karuka?
Normally the wild karuka belongs to the clan on whose land it is growing. Different clans
have different areas of wild karuka. The pattern may vary in different places but the commonest
method of looking after wild karuka in the SHP is: The clan own the karuka. Individual people
within the clan are given permission to look after different sections or trees. These people clear the
bush near the base of the tree and build traps to stop tree kangaroos. When the tree bears fruit, the
person who has been looking after that tree is allowed to share out that fruit with the other people in
his clan. At karuka nut time often lots of friends come from other places to eat karuka.
What does the fruit look like?
As a wild karuka plant is getting ready to produce a bunch of nuts the leaves at the top of
the tree go tightly together and stick straight up. Then the top of the leaves become a red colour
(With cultivated karuka the top of the leaves change to a white colour.)
The round clump of nuts grows out of the top of the tree amongst the leaves then falls
over to hang near the trunk amongst the dead leaves. The fruit has green leaf like bracts over it. If
these green bracts are taken off, the clump of nuts that make up the fruit look like this next picture.
Fruit still
covered by
bracts
Harvesting karuka
Sometimes the wild karuka fruit is not harvested by climbing but the nuts are allowed to
fall. At least when the first few nuts start to fall people know the karuka is ready for harvesting.
The shells of wild karuka nuts are very hard. They are broken with a stone or axe. Sometimes the
nuts are buried in the ground to let the shells soften before breaking them open to eat the kernel.
339
During the wild karuka season families often go to the bush and take their pigs. They
build temporary houses from the leaves of karuka and stay in the bush living off karuka nuts and
wild animals.
The inside of a wild karuka is very similar to a cultivated karuka. The soft spongy layer
around the nuts between the stalk and the nuts can also be eaten. The wild karuka nut looks much
like a cultivated karuka nut except that the outside is a little bit rougher with fibres and the end with
the fibrous hairs is longer and has a sharper point.
nut
Surface of fruit
The wild karuka season
It is not easy to say when the wild karuka season occurs. It is possible to have a good
season for cultivated karuka and yet in the same area to have a poor season for wild karuka. All
places do not have a good wild karuka season in the same year. But the probable pattern is that the
season is either at Christmas or mid year or it can occur at both times. Also trees probably only
have a clump of fruit every two years.
Pests and diseases
Wild karuka does not seem to get many leaf spots even when it is planted next to a
cultivated karuka which has many disease leaf spots. Other diseases of wild karuka seem very rare
but because the plants are scattered and spread around in the bush, it may be that trees simply avoid
the diseases.
Tree kangaroos are a problem with wild karuka the same as they are with cultivated
karuka. People build similar traps to stop them climbing the trees.
Pandanus antaresensis
(Scientific name)
No common Tok Pisin of English name.
Tok ples names:
Mendi: - pem, pembras
Imbongu: - kupili
The plant
This pandanus grows naturally between about 1600 and 2500 metres altitude in the
highlands.
It often grows in swampy places.
Most trees have a number of widely spaced branches. At the top of these there is normally a
shoot of leaves making a point which points upwards.
The leaves are often a light green. They have thorns along the edge, although the thorns are
normally less about the middle of the leaf.
The cluster of nuts hangs down below the leaves on a long stalk.
The pandanus fruit
The fruit of this tree is made up of clusters of nuts grouped together in groups of 4 or 5 nuts.
Together they make up a round knobbed cluster about 30 cm across.
As the fruit matures the cluster turns an orange colour and the small groups of nuts fall, one
by one.
341
An individual group of nuts that fall down look like this.
As the nuts dry out, lots of hairy looking fibres can be seen. The shell is hard and must be
broken with an axe or a stone. The nut inside is small.
Because the shell is hard and the nut small some people don't eat these nuts at all. Other
people only eat them sometimes. But some people plant these pandanus near their gardens and like
the nuts.
The Okari nut family
Terminalia catappa
Terminalia impediens
Terminalia copelandii
Terminalia kaernbachii
343
Okari
Tok Pisin: Okari
Scientific name: Terminalia kaernbachii
The okari nut tree
This tree grows up to 40 m tall. The tree has distinctive type of branching where branches
come out in several "layers" along the trunk. The branches also have short thick twigs along them
and the leaves tend to be in clusters near the ends of branches. The leaves are large (25 cm x 15
cm) and have reddish brown hairs underneath.
At the ends of the branches the tree produces a long flower shoot and the fruits develop on
it. A number of fruits can grow on the end of the one twig.
The fruits are flattened and green when young. As they ripen they change to a red colour.
Inside the fruit is a hard shell and the kernel is inside this shell. It is this kernel or nut that is
eaten.
One layer of
branches with
clumps of leaves
of an okari tree
Where do okari nuts grow?
The okari nut tree grows in the lower areas below about 800 metres altitude. Some trees
growing near Erave (1100 m) only have a few fruit on them although the trees grow well. The best
yield of nuts comes from the lower areas.
Other trees like Okari
Several trees with the name Terminalia are used in Papua New Guinea for edible nuts.
These include the Java almond and Talis. All these trees have the same distinctive type of
branching. The branches come out in layers and they have thick twigs that come out at right angles.
A diagram of the type
of branching of trees
called Terminalia.
Okari and some other
nut trees like it have
this type of branching.
What is an Okari fruit and nut like?
The okari fruit is a green, slightly flattened fruit that becomes dark red when ripe. The
outside layer is soft and fleshy.
Two young green fruits
on a twig.
A mature fruit can be up to 20 cm long and 10 cm wide. It is oval in shape and slightly
flattened.
A ripe red okari nut
fruit.
This fruit is split open with an axe to reveal the kernel that is inside the hard shell. The shell
has ridges and holes in it.
A fruit, shell and kernel
345
It is the kernel inside the shell that is eaten. The kernel can be 7-8 cm long and 3-4 cm
wide.
The kernel is made up of coiled leaves that make up the seed. A kernel can weigh up to 10
grams in weight. These are eaten either raw or after a slight roasting.
Growing trees and producing nuts
Okari nut trees are normally grown from seeds. The trees grow very fast and they can
increase in height by up to 2 metres in one year. But trees need to be fairly old before they produce
many nuts. Twenty year old trees often only produce a few nuts.
Pest problems
Not a lot of insect or disease problems have been recorded on okari nut trees, but these may
not have been well looked at.
Trees can get a leaf spot due to a fungus.
They can also get sooty mould fungus growing over the surface of the leaves. This is a
black sooty like covering over the leaves. This fungus is really only growing on the rubbish left
behind by small insects and can be rubbed off the leaf. But it can block out the sunlight.
Some larvae of moths belonging to the armyworm family have been recorded eating leaves
of Okari nut trees.
Diseases
Leaf spot
Sooty mould
Cercospora sp.
Lembosia terminaliae Hansf.
Larvae on leaves
Insect for mould
Borer termite
Aiteta iridias Meyr.
Perissopneumon mealybug
Neotermes sp.
Insect pests
Talis
Name: Talis
Scientific name: Terminalia impediens
(Other Terminalia are also called Talis)
The plant
A tree that grows up to 42 m tall. Often the tree has buttresses. The twigs are usually fairly
large. The young parts of the tree are sometimes hairy. The young leaves are purple underneath. It
has leaves that are clustered at the ends of thick twigs. Leaves can be 25 cm x 12 cm or larger and
they taper towards the stalk. The leaves are often blunt at the tip. The leaves often have a purplish
colour underneath. The flowers occur on spikes 10-30 cm long. The flowers are small. The flower
spikes are longer than okari nut (Terminalia kaernbachii) and less hairy looking. The fruit are 7-9
cm long by 3.5-6 cm wide. They are red and have fibrous flesh. They usually do not have a wings
or flanges. Inside there is a large woody stone. The stone inside the fruit splits into 2 unequal parts.
The 2 kernels inside are edible.
It occurs in the lowland forest in Papua New Guinea. Trees grow wild and are preserved in
gardens. They grow from seed. The kernel inside the hard shell of the fruit is edible.
347
Coastal almond
Names: Indian almond, Coastal almond
Scientific name: Terminalia catappa
The plant
A large tree that grows up to 25-40 m tall. It loses its leaves during the year. The trunk can
be straight or twisted. There can be buttresses up to 3 m tall. The branches lie horizontally and
come out in layers. The leaves are long, smooth and shiny with an abrupt point at the tip and a
rounded base. Leaves tend to be near the ends of branches. Leaves can be 17-29 cm long and 1015 cm wide. Young leaves have soft hairs. The leaves turn red and fall off twice a year. Flowers
are greenish white and in a spike at the end of the branches. The lower flowers on a spike are
female, then the others are male. The fruit is about 6 cm long by 3-4 cm wide, thick and flattened
with a flange around the edge. The fruit are green and turn red when ripe. The pulp is edible.
Where does it grow?
It is a tropical plant. This tree occurs on the beachfront in most tropical countries in the
world. They occur near the seashore from northern Luzon to southern Mindanao in the Philippines.
They are sometimes cultivated as a shade tree. The tree is common in lowland areas particularly on
sandy or rocky beaches. Seeds are spread by both bats and seawater as well as being planted by
people. Trees are common along streets in coastal towns. They will grow from sea level up to
about 800 m altitude. Plants are frost tender. They can tolerate drought. It suits hardiness zones
11-12.
How do you grow Coastal almond?
Plants can be grown from seed. Seeds can be stored dry for a year or more. Seeds germinate freely
and most seeds grow. Insects can badly damage the leaves of young seedlings. It is fast growing.
Nut production is seasonal.
Coastal almond as food
The kernels of the fruit are eaten raw.
An edible oil can also be extracted.
Moisture
%
Energy
KJ
Protein
%
ProVit A
µg
Provit C
mg
Iron
mg
Zinc
mg
4.2
2987
20.0
0
2
6.3
41.0
This means the nuts are good for energy and protein and are especially high in zinc that is needed
by all growing children.
349
Pao or Barringtonia nuts
Barringtonia edulis
Barringtonia novae-hibernae
Barringtonia procera
Barringtonia niendzuema
Barringtonia racemosa
Pao nuts
Scientific name: Barringtonia spp.
What is the plant like?
A pao nut tree is a small tree in the coastal areas of Papua New Guinea. The tree grows up
to 6 or 8 metres tall. The trunk is often only 10-15 cm across and near the top the tree has a few
short thick branches.
The leaves are large and shiny. The leaves are crowded towards the end of branches. A leaf
can be 50 or 60 cm long and 20-24 cm across. Near the tip of the leaf the edge is wavy and often
slightly toothed, with the tip bent backwards. The veins of the leaf show up clearly on both sides of
the leaf. The leaf stalk is only short about 1 cm long.
A long hanging yellow flower is produced from the branches. It can be 80 cm long and is
densely covered with flowers. There can be up to 120 flowers along a stalk. The flowers do not
have a scent. Along this stalk the fruits form, giving a long hanging stalk of quite large nuts.
The fruit is oval shaped and about 6-8 cm long by 3-4 cm across. The seed or nut inside the
fruit has lines running along its surface. This edible part is about 3 cm long by 1-2 cm across and
white coloured. The seed is flattened particularly on one side.
351
Pao nuts
Pao nut trees tend to flower and produce nuts throughout the year.
There are some different kinds. The size and shape of the nuts can vary slightly. Also some
are white inside and some are red. The most obvious difference is the colour of the outside of the
fruit. Some kinds are green or slightly blue whereas other kinds are a dark reddish black.
The nuts have a fairly hard shell and are split open with a knife. The white part in the centre
is eaten raw. It also has a fairly hard texture.
Naming of Pao nut trees
Pao nut is one of the more common Tok Ples names for these nuts and is often used for
them in Tok Pisin. They also have different Tok Ples names and they have been given scientific
names by scientists.
Two species are grown and used as food in Papua New Guinea. The scientific names of the
two plants are:
and
Barringtonia procera
Barringtonia novae-hibernae.
In 1875, the first plant was named Butonica procera by a botanist named Miers. As more
was learned about the plant it was renamed Barringtonia procera in 1939 by another scientist
named Knuth. Sometimes other names like Barringtonia magnifica have been used for this plant.
They have now been replaced. The other species was first named by a botanists called Lauterbach
in 1911. The name Barringtonia was given after and English naturalist Daniel Barrington who was
born in the year 1800.
Barringtonia procera is a less branched tree and tends to grow nearer the coast. The leaves
are larger.
Barringtonia novae-hibernae has a more branched trunk and a smaller leaf. It grows more
inland and has a sweeter nut.
In Fiji, a very similar, but different species is used for its edible nut. The scientific name of
this species is Barringtonia edulis. It does not occur in Papua New Guinea but sometimes this
name has been used incorrectly for the Papua New Guinea plant.
TOK PLES NAMES
Papua New Guinea
Province
Madang
Morobe
Manus
New Ireland
New Britain
North Solomons
Solomon Islands
Province
Shortland Is
New Georgia
San Cristobal
Santa Cruz
Vanuatu
Province
Language
B. procera
Laluan
B. novae-hibernae
Tegeli
Pao
Pulei/purei
Pao
Pao
Pala
Kuanua
Siwai
Paua-hutun
Pao-vutug
Hari
Language
B. procera
Borolong
Tinga
Hara
Nua
B. novae-hibernae
Sioko
Hala/fala/kenu
Hara
Nuado
Language
B.procera
Va rodh
B.novae-hibernae
Vevingen
Because there are some very poisonous Barringtonia trees it is important to check with
local people both the names and which ones are used as food. One tree is commonly used as a
fish poison to stun fish.
Where do Pao nut trees grow?
Pao nuts mostly grow in tropical lowland coastal areas. In Papua New Guinea they are
common along the North coast at places such as Madang and nearby islands, then they are very
common in New Ireland and occur on New Britain near Rabaul. They also grow in the Solomon
Islands and in Vanuatu. A similar, but different tree grows in Fiji.
The map below will show you some of the places where pao nuts are known to occur.
353
How do you grow pao nut trees?
Pao nut trees are mostly grown from seed. Several different races or types of pao nut have
been selected by villagers and these trees seem to produce fruit that is similar to the seed that was
planted.
Trees can be grown from stem cuttings. Trees grown from cuttings have shorter trunks and
branch closer to the ground.
If trees are planted in suitable sites and well looked after they can produce fruit in a year or
two.
As pao nuts often do well and are most common on low off shore islands and coral
waterfront villages, it may be particularly suited to coral and alkaline soils. This needs to be further
studied.
The major food plants of Papua New Guinea
Aleurites moluccana (L) Willdenow
Allium cepa var aggregatum G.Don
Allium porrum L
Alocasia macrorrhiza (L) Schott
Amaranthus spp.
Amorphophallus paenifolius (Roxb) Bl
Ananas comosus (L) Mead
Annona muricata L.
Annona squamosa L.
Arachis hypogea L.
Areca cathecu L.
Artocarpus altilis (Parkinson) Fosberg
Artocarpus heterophyllus Lam.
Averrhoa carambola L.
Baccaurea papuana F.M.Bail.
Barringtonia novae-hibernae Laut
Barringtonia procera (Miers) Knuth
Basella alba L.
Brassica oleracea var capitata L.
Brassica sinensis
Burckella obovata (Forst.) Pierre
Cajanus cajan (L) Millsp.
Canarium indicum L.
Canavalia ensiformis D.C.
Canna edulis Ker
Capsicum annuum L.
Capsicum frutescens L.
Carica papaya L.
Castanopsis acuminatissima (Bl.) A.DC.
Citrullus lanatus (Thunb.) Mansf.
Citrus spp
Clymenia polyandra (Tanaka) Swingle
Cocos nucifera L.
Colocasia esculenta Schott
Corynocarpus cribbianus (FM Bail) L.S.Sm
Cucumis sativus L.
Cucurbita spp.
Cyathea contaminans (Wall ex Hook) Copel
Cyphomandra betakea (Cavanilles) Sendtner
Cyrtosperma merkusii (Schott) Merrill
Dicliptera papuana Warb
Dioscorea alata L.
Dioscorea bulbifera L.
Dioscorea esculenta (Loureiro) Burkill
Dioscorea pentaphylla L.
Diplazium esculentum (Retz.) Sw.
Dracontomelon dao (Blanco) Merr. & Rolfe
Durio zibethinus Murray
Elaeocarpus spp.
Ficus copiosa Steud.
355
Candle nut
Spring onion
Leek
Giant taro
Amaranths
Elephant foot yam
Pineapple
Soursop
Sweetsop
Peanuts
Betel nut
Breadfruit
Jackfruit
Five corner
314
219
218
61
110
59
284
238
240
187
Pao nuts
Pao nuts
Indian spinach
Cabbage
Chinese cabbage
Bukubuk
Pigeon pea
Galip nuts
Sword bean
Queensland arrowroot
Capsicum
Chilli
Pawpaw
Castanopsis chestnuts
Watermelon
Oranges, lemons, limes
Clymenia
Coconut
Taro
Mundroi
Cucumber
Pumpkins
Tree ferns
Tree tomato
Swamp taro
Dicliptera
Greater yam
Potato yam
Lesser yam
Five leaflet yam
Fern
Mon
Durian
Elaeocarpus nuts
Kumu musong
350
350
306
310
242
167
168
224
324
151
98
172
174
279
316
298
226
226
318
65
269
209
210
122
273
63
134
83
88
84
89
123
265
128
Ficus dammaropsis Diels
Finschia chloroxantha Diels
Flacourtia spp.
Gnetum gnemon L.
Hibiscus manihot L.
Inocarpus fagifer (Parkinson) Fosberg
Ipomoea aquatica Forskal
Ipomoea batatas (Linnaeus) Lam.
Ipomoea macrantha
Lablab purpureus (L.) Sweet
Lagenaria siceraria (Molina) Standley
Luffa acutangula (L.) Roxburgh
Luffa cylindrica (L.) M.Roemer
Lycopersicon esculentum Miller
Maesa edulis White
Mangifera indica L.
Manihot esculenta Crantz
Metroxylon sagu Rottb.
Metroxylon solomonense (Warburg) Becc.
Momordica charantia L.
Morinda citrifolia L.
Morus nigra L.
Musa sp (A &/or B genome) cv.
Myristica holrungii Warb
Nasturtium officinale R.Br.
Nasturtium schlechteri O.E. Schultz
Nastus elatus Holttum
Nypa fruticans Wurmb
Oenanthe javanica D.C.
Omphalea gageana Pax. & Hoffm.
Ormocarpum orientale (Spreng) Merr
Oryza sativa L.
Pandanus antaresensis St John
Pandanus brosimos Merrill & Perry
Pandanus conoideus Lamarck
Pandanus jiulianettii Martelli
Pandanus tectorius (Solander) Parkinson
Pangium edule Reinw
Parartocarpus venenosa (Z & M) Becc
Passiflora quadrangularis L.
Passiflora spp.
Persea americana Mill.
Phaseolus lunatus L.
Phaseolus vulgaris L.
Piper betle L.
Polyscias spp.
Pometia pinnata J.R.& G Forster
Psidium guava L.
Psidium littorale Raddi
Psophocarpus tetragonolobus (L.) D.C.
Pueraria lobata (Willd.) Ohwi
Rubus spp.
Highlands "kapiak"
Finschia
Lovilovi
Tu lip
Aibika
Aila
Kangkong
Sweet potato
Fongaar
Lablab bean
Bottle gourd
Angled loofah
Smooth loofah
Tomato
125
328
257
137
104
302
128
42
99
156
204
211
212
Mango
Cassava
Sago
Solomon's sago
Bitter cucumber
Indian mulberry
Mulberry
Banana
257
20
31
40
213
249
265
7
Watercress
142
143
150
Highlands bamboo
Nipa palm
Waterdropwort
Kalava
Rice
Wild karuka
Marita
Karuka
Coastal pandanus
Sis
Pakal
Granadilla
Passionfruits
Avocado
Lima bean
Common bean
Daka
Valanguar
Ton
Guava
Cherry guava
Winged bean
Kudzu
Raspberries
147
131
341
338
258
331
312
276
276
221
155
153
135
296
246
246
74
Rungia klossii S.Moore
Saccharum edule Hasskarl
Saccharum officinarum L.
Sechium edule (Jacquin) Swartz
Setaria palmifolia (Koenig) Stapf
Solanum nigrum L.
Solanum quitoense Lam.
Solanum tuberosum L.
Spondias cytherea Sonnerat
Stenochlaena palustris (Burm.f) Bedd
Syzygium aquea Burm.f.
Syzygium malaccensis L.
Eugenia uniflora L.
Tacca leontopetaloides (L.) O.Kuntze
Talinum triangulare (Jacq.) Willd.
Terminalia catappa L.
Terminalia spp.
Trichosanthes cucumerina L.
Trichosanthes pulleana Cogn ex Harms
Triphasia trifolia (Burm.f.) P.Wils
Vigna unguiculata subsp unguiculata
Vigna unguiculata subspsesquipedali (L. Verdc.)
Xanthosoma sagittifolium (L.) Schott
Zea mays L.
Zingiber officinale Rosc.
357
Rungia
Long pitpit
Sugarcane
Choko
Highland pitpit
Blackberried nightshade
Naranjilla
Potato
Golden apple
Climbing swamp fern
Watery rose apple
Malay apple
Surinam cherry
Polynesian arrowroot
Waterleaf
Java almond
Okari, talis
Snake gourd
132
187
287
206
193
118
271
26
244
121
254
253
255
96
147
348
343
Limeberry
Cowpea
Snake bean
Chinese taro
Corn
Ginger
226
154
153
54
174
176
Alphabetical index of common name
Baccaurea papuana F.M.Bail.
Maesa edulis White
Myristica holrungii Warb
Nasturtium schlechteri O.E. Schultz
Omphalea gageana Pax. & Hoffm.
Pandanus antaresensis St John
Trichosanthes pulleana Cogn ex Harms
Aibika
Hibiscus manihot L.
Aila
Inocarpus fagifer (Parkinson) Fosberg
Amaranths
Amaranthus spp.
Angled loofah
Luffa acutangula (L.) Roxburgh
Avocado
Persea americana Mill.
Banana
Musa sp (A &/or B genome) cv.
Betel nut
Areca cathecu L.
Bitter cucumber
Momordica charantia L.
Blackberried nightshade
Solanum nigrum L.
Bottle gourd
Lagenaria siceraria (Molina) Standley
Breadfruit
Artocarpus altilis (Parkinson) Fosberg
Bukubuk
Burckella obovata (Forst.) Pierre
Cabbage
Brassica oleracea var capitata L.
Candle nut
Aleurites moluccana (L) Willdenow
Capsicum
Capsicum annuum L.
Cassava
Manihot esculenta Crantz
Castanopsis chestnuts
Castanopsis acuminatissima (Bl.) A.DC.
Cherry guava
Psidium littorale Raddi
Chilli
Capsicum frutescens L.
Chinese cabbage
Brassica sinensis
Chinese taro
Xanthosoma sagittifolium (L.) Schott
Choko
Sechium edule (Jacquin) Swartz
Climbing swamp fern
Stenochlaena palustris (Burm.f) Bedd
Clymenia
Clymenia polyandra (Tanaka) Swingle
Coastal pandanus
Pandanus tectorius (Solander) Parkinson
Coconut
Cocos nucifera L.
Common bean
Phaseolus vulgaris L.
Corn
Zea mays L.
Cowpea
Vigna unguiculata subsp unguiculata
Cucumber
Cucumis sativus L.
Daka
Piper betle L.
Dicliptera
Dicliptera papuana Warb
Durian
Durio zibethinus Murray
Elaeocarpus nuts
Elaeocarpus spp.
Elephant foot yam
Amorphophallus paenifolius (Roxb) Bl
Fern
Diplazium esculentum (Retz.) Sw.
Finschia
Finschia chloroxantha Diels
Five corner
Averrhoa carambola L.
Five leaflet yam
Dioscorea pentaphylla L.
Fongaar
Ipomoea macrantha
Galip nuts
Canarium indicum L.
Giant taro
Alocasia macrorrhiza (L) Schott
Ginger
Zingiber officinale Rosc.
Golden apple
Spondias cytherea Sonnerat
143
341
104
302
110
211
221
7
213
118
204
306
224
167
314
172
20
316
246
174
168
54
206
121
226
318
153
174
154
209
134
59
123
328
242
89
99
324
61
176
244
Granadilla
Greater yam
Guava
Highland pitpit
Highlands "kapiak"
Highlands bamboo
Indian mulberry
Indian spinach
Jackfruit
Java almond
Kalava
Kangkong
Karuka
Kudzu
Kumu musong
Lablab bean
Leek
Lesser yam
Lima bean
Limeberry
Long pitpit
Lovilovi
Malay apple
Mango
Marita
Mon
Mulberry
Mundroi
Naranjilla
Nipa palm
Okari, talis
Oranges, lemons, limes
Pakal
Pao nuts
Pao nuts
Passionfruits
Pawpaw
Peanuts
Pigeon pea
Pineapple
Polynesian arrowroot
Potato
Potato yam
Pumpkins
Queensland arrowroot
Raspberries
Rice
Rungia
Sago
Sis
Smooth loofah
Snake bean
Passiflora quadrangularis L.
Dioscorea alata L.
Psidium guava L.
Setaria palmifolia (Koenig) Stapf
Ficus dammaropsis Diels
Nastus elatus Holttum
Morinda citrifolia L.
Basella alba L.
Artocarpus heterophyllus Lam.
Terminalia catappa L.
Ormocarpum orientale (Spreng) Merr
Ipomoea aquatica Forskal
Pandanus jiulianettii Martelli
Pueraria lobata (Willd.) Ohwi
Ficus copiosa Steud.
Lablab purpureus (L.) Sweet
Allium porrum L
Dioscorea esculenta (Loureiro) Burkill
Phaseolus lunatus L.
Triphasia trifolia (Burm.f.) P.Wils
Saccharum edule Hasskarl
Flacourtia spp.
Syzygium malaccensis L.
Mangifera indica L.
Pandanus conoideus Lamarck
Dracontomelon dao (Blanco) Merr. & Rolfe
Morus nigra L.
Corynocarpus cribbianus (FM Bail) L.S.Sm
Solanum quitoense Lam.
Nypa fruticans Wurmb
Terminalia spp.
Citrus spp
Parartocarpus venenosa (Z & M) Becc
Barringtonia novae-hibernae Laut
Barringtonia procera (Miers) Knuth
Passiflora spp.
Carica papaya L.
Arachis hypogea L.
Cajanus cajan (L) Millsp.
Ananas comosus (L) Mead
Tacca leontopetaloides (L.) O.Kuntze
Solanum tuberosum L.
Dioscorea bulbifera L.
Cucurbita spp.
Canna edulis Ker
Rubus spp.
Oryza sativa L.
Rungia klossii S.Moore
Metroxylon sagu Rottb.
Pangium edule Reinw
Luffa cylindrica (L.) M.Roemer
Vigna unguiculata subspsesquipedali (L. Verdc.)
359
276
83
246
193
125
150
249
310
348
131
128
331
128
156
218
84
155
226
187
257
253
257
258
265
265
269
271
343
226
312
350
350
276
279
187
284
96
26
88
210
98
132
31
212
153
Snake gourd
Solomon's sago
Soursop
Spring onion
Sugarcane
Surinam cherry
Swamp taro
Sweet potato
Sweetsop
Sword bean
Taro
Tomato
Ton
Tree ferns
Tree tomato
Tu lip
Valanguar
Watercress
Waterdropwort
Waterleaf
Watermelon
Watery rose apple
Wild karuka
Winged bean
Trichosanthes cucumerina L.
Metroxylon solomonense (Warburg) Becc.
Annona muricata L.
Allium cepa var aggregatum G.Don
Saccharum officinarum L.
Eugenia uniflora L.
Cyrtosperma merkusii (Schott) Merrill
Ipomoea batatas (Linnaeus) Lam.
Annona squamosa L.
Canavalia ensiformis D.C.
Colocasia esculenta Schott
Lycopersicon esculentum Miller
Pometia pinnata J.R.& G Forster
Cyathea contaminans (Wall ex Hook) Copel
Cyphomandra betakea (Cavanilles) Sendtner
Gnetum gnemon L.
Polyscias spp.
Nasturtium officinale R.Br.
Oenanthe javanica D.C.
Talinum triangulare (Jacq.) Willd.
Citrullus lanatus (Thunb.) Mansf.
Syzygium aquea Burm.f.
Pandanus brosimos Merrill & Perry
Psophocarpus tetragonolobus (L.) D.C.
40
238
219
287
255
63
42
240
151
65
296
122
273
137
135
142
147
147
298
254
338
74
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