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APPENDIX A

Contents: abbreviated analysis of variance (ANOY A) tables

199

Tab l e

IA Analysis of variance of total dry mass ( r oots

+ shoots) of maize seedlings exposed to atrazine in aqueous medium in the NPK-experiment (Table 4 , Chapter 2)

Source

Nutrient (Ntr)

Atrazine (A)

Ntr x A

Error

Total

C.Y.

(%)

R 2

DF

7

2

14

72

95

Total dry mass

MS

F value

23.50

179.01

17.64

1.30

18 .00

137.07

13.51

25

0 .

89

PR

>

0 .

0001

0.0001

0.0001

F

Tab l e

2A Analysis of variance of percent damage to maize seedlings exposed to atrazine in aqueous medium in the NPK-experiment (Table 4 , Chapter 2)

Source

Nutrient (Ntr)

Atrazine (A)

Ntr x A

Error

Total

C.Y.

(%)

R 2

DF

7

7

48

63

Total dry mass

MS

F va l ue

1836.6

6506.7

264.9

185 .

9

9.06

32.09

1.31

30

0 .

70

PR

>

F

0.0001

0.0001

0 .269

8

200

Table 3A Analysis of variance of leaf diffusive resistance of maize seedlings exposed to atrazine in aqueous medium in the NPK-experiment (Table 5 , Chapter 2)

Source

Nutrient (Ntr)

Atrazine (A)

Ntr x A

Error

Total

C.Y.

( % )

R 2

DF

7

2

14

72

95

Leaf diffusive resistance

MS F value

2.98

103.29

0.49

0.96

3.09

106.92

0.51

12

0.77

PR > F

0.0066

0.0001

0.9196

,

Table 4A Analysis of variance of percent atrazine remaining 0 , 14 and 28 days after application of the herbicide in aqueous medium in the NPK experiment (Figure 1 ,

Chapter 2)

Source

Time (T)

Nutrient (Ntr)

Atrazine (A)

T x Ntr

TxA

Ntr x A

T x Ntr x A

Error

Total

C.Y.

( % )

R 2

14

2

7

14

48

95

DF

2

7

Percent atrazine remaining in solution

MS F value PR > F

33645.9

270.1

12.3

159.8

32 .

2

123.3

69.1

44.9

749.29

6.02

0.28

3 .56

0.72

2 .

75

1.54

0.0001

0 .

0001

0 .

6024

0 .

0005

0.4924

0 .

0176

0 .

1334

9

0.97

201

Tab l

e SA Analysis of variance of total dry mass of maize seedlings exposed to atrazine in aqueous medium in the CaMg-experiment (Table 6, Chapter 2)

Source

Nutrient (Ntr)

Atrazine (A)

Ntr x A

Error

Total c.y.

( % )

R '

DF

3

2

6

48

59

MS

Total dry mass

F value

10 .

05

1 68.49

15 .

06

2 .

60

3.86

64 .

71

5.79

29

0.78

PR > F

0 .

0149

0.0001

0.0001

Table 6A

Analysi s of varianc e of percent damage to maiz e s eedlings exposed to atrazine in aqueou s medium in the CaMg-experiment (Table 6 , Chapter 2)

Source

Nutrient (Ntr)

Atrazine (A)

Ntr x A

Error

Total

C.Y. ( % )

R '

DF

3

3

32

39

MS

Total dry mass

F value

3709.7

8342.3

10.44

23.47

476 .

0

355.4

1.34

39

0.64

PR

>

F

0.0001

0 .

0001

0 .

2789

202

T a bl e

7 A Analysis of variance of leaf d i ffusive resistance of maize seedlings exposed to at r azine in aqueous medium in the CaMg experiment (Table 7, Chapter 2)

Source

Nutrient (Ntr)

Atrazine (A)

Ntr x A

Error

Total

C.Y

. (%)

R 2

DF

3

2

6

36

47

Leaf diffusive resistance

MS

F value

6.01

101.56

10.33

6.33

0 .

95

16 .

04

1.63

PR

>

F

0.4269

0 .

0001

0.1666

32

0 .

55

Tab l e SA

Analysis of variance of percent atrazine remaining

0 , 14 and

28 days after app l ication in aqueous medium in the CaMg-experiment (Figure

2,

Chapter

2)

Source

Time (T)

Nutrient (Ntr)

Atrazine (A)

T x Ntr

TxA

Ntr x A

T x Ntr x A

Error

Total

C.Y. (%)

R 2

6

48

71

6

2

3

DF

2

3

Percent atrazine remaining in solution

MS F value

PR

>

F

31432.5

482 .

2

402.9

128.3

101.9

19.6

5.2

51.1

615 .

6

9.45

7.89

2.51

2.00

0.38

0.10

0.0001

0.0001

0.0072

0.0339

0.1469

0.7649

0.9958

12

0.96

203

T ab l e 9A Analysis of variance of total dry mass (roots

+ shoots) of maize seedlings exposed to different PI eve l s and atrazine in aqueous medium (Table 9, Chapter

2)

Source

Phosphorus (P)

Atrazine (A)

PxA

Error

Total c.Y.

( % )

R 2

DF

5

2

10

90

107

Dry mass (g planrl)

MS F value

0.12

75.97

0.09

0.Q7

1.73

1070.45

1.35

14

0.96

PR

>

F

0.1360

0.000 1

0 .

2161

Tab l e

lOA

Analy s is of variance of leaf d i ffusive resistance of maize seedlings exposed to different PI evel s and atrazine in aqueous medium (Tab l e 9 , Chapter 2)

Source

Phosphorus (P)

Atrazine (A)

PxA

Error

Total c.Y

.

( % )

R 2

DF

5

2

10

90

107

Leaf diffusive resistance (s em I)

MS

258 .

1

6177.3

75 .

9

32 .

7

F value

7 .

88

188.57

2.32

PR

>

F

0 .

0001

0.000 1

0.0177

26

0.83

204

Ta bl e ll A

Analys i s of varia n ce of total dry m ass ( r oots

+ s h oots) of m aize seed l ings exposed t o a tr az i ne i n n utrie nt so l ut i o n s conta i n i ng different combinatio n s of P a n d

NH . + :NO, -N ra ti os (Tab l e 10, Chapte r 2)

Source

P/NH/ : NO ,-

( N tr)

Atrazi n e (A)

N t r x A

Error

Total

C.Y.

(%)

R 2

DF

4

2

8 lOS

119

Dry m ass (g p l a n r')

MS F va lu e

2.0

5

4 .77

0.09

0.02

85.12

197.9

1

3.57

12

0 .

87

PR

>

F

0.0001

0.000

1

0.00

11

T a bl e 12A

Ana l ysis of variance of photosy nt he ti c Co, fixa ti on tempo of m aize seedlings exposed to a t raz i ne i n n ut rien t so lu t i ons con t aining diffe r ent co mb i n a ti ons of

P and NH. + :N O ,-N r at i os (Table 11 , Chapter 2)

Source

P / NH / : N O ,-

(Ntr)

A t raz in e (A)

Nt r x A

E rr or

Total

C.Y.

(%)

R 2

DF

4

2

8

45

59

COrfixat i on tempo ( 01 g 01 -

2 s ' )

MS

0.

1 20

3 .

954

0.095

0 .

035

F val u e

1 1

3.45

3.78

2.72

PR

>

F

0.0

1 54

0 .

0001

0.0

1 54

1 9

0.85

20 5

T a bl e 13 A

Analys i s of variance of perce n t P in shoots of maize seedlings exposed to atrazine in solut i ons conta

(Table 10 , Chapter 2) i n i ng d i fferent combinations of P and NH., + :N0

3-

-N ratios

Source

P / NH / :N0

3-

(Ntr)

Atrazine (A)

Ntr x A

Error

Total

C .

Y. ( % )

R 2

DF

4

2

8

15

29

Percentage P in shoots

MS

0.99

0 .

1

0.898

034

0.016

F value

62.23

56 .

39

2.13

II

0.96

PR

>

F

0.0001

0.0001

0.0981

Table 14A

Analysis of variance of grain yield of maize exposed to different fertilizer

(3:2: 1 25 % ) a nd atrazine rates in t h e field (Table 13 , C h apter 2)

Source

Replicate (R)

Fertilizer (F)

Atrazine (A)

FxA

E rror a (A x R)

Error b (F x R)

Error c (A x F x R)

Total

C.Y.( % ) Main plots

C .

Y.( % ) Sub-plots

R 2

DF

6

24

2

4

12

8

48

104

MS

1.05

2.22

3.24

0 .

36

0.34

1.37

0 .

22

Grain yield (ton ha ')

F value

0.54

1.62

9 .

59

1.65

0 .

31

18

71

PR

>

F

0 .

3675

0 .

2607

0.0005

0 .

0692

206

Table 1

SA Analysis of variance' of percent reduction in growth caused by atrazine to dry beans and sunflower in a glasshouse (Table 15, Chapter 3)

Source

Replicate

Crop (C)

Soil

(S)

Atrazine (A)

CxS

CxA

SxA

CxSxA

Error

Total

2

C.Y.

( % )

R 2

OF

2

8

9

72

72

8

9

355

536

Percent reduction in top growth dry mass

MS F value PR

>

F

26

50577

38410

19770

2133

673

1067

318

49

0 .

5

1049.7

797 .

2

410.3

44 .

3

\3.9

22 .

2

6.6

0.5888

0.0001

0.0001

0.0001

0.0001

0.0001

0.0001

0.0001

20

0.97

'ANOYA conducted on data from Experiment I.

2 Number of missing values

=

3 (unsatisfactory emergence at three separate treatment combinations) .

207

Tab l e 1

6A Analysis of variance' of percent reduction i n growth caused by atrazine to oats and soybeans in a glasshouse (Table 16, Chapter 3)

Source

Replicate

Crop (C)

Soil (S)

Atrazine (A)

CxS

CxA

SxA

CxSxA

Error

TotaJ2 c.Y. (%)

R 2

72

72

8

9

8

9

DF

2

356

537

Percent reduction in top growth dry mass

MS

F value PR

>

F

0.2546

39

68431

13178

18518

438

620

346

588

29

1.4

2394.2

461.1

647.9

15.3

21.7

12.1

20.6

0.0001

0.0001

0.0001

0.0001

0.0001

0.0001

0 .

0001

II

0.97

'ANOY A conducted on data from Experiment

1.

2 Number of missing values

=

2 (unsatisfactory emergence at two separate treatment combinations).

208

Table 17 A

Dry beans alone: analysis of variance of percent growth reduction caused by atrazine (Table 17, Chapter 3)

Source

Replicate

Soil (S)

Atrazine (A)

SxA

Error

TotaJi

C.Y. ( % )

R 2

DF

2

72

174

265

8

9

Percent reduction in top growth dry mass

MS F value PR

>

F

45

14752

7041

723

53

0.85

278.40

132.87

13 .

65

0.4281

0.0001

0.0001

0 .

0001

29

0.96 lFour missing values were recorded due to unsati s factory emergence at four separate treatment combinations.

Table 18A

O a ts alone : analysis of variance of percent reduction in growth cau s ed by atrazine (Table 18 , Chapter 3)

Source

Replicate

Soil (S)

Atra z ine (A)

SxA

Error

Total

C.Y.

( % )

R 2

DF

2

9

9

81

198

299

Percent reduction in top growth dry mass

MS

F value PR

>

F

73

16569

11312

527

30

2.45

554 .

71

378.72

17.65

0.0886

0.0001

0 .

0001

0.0001

10

0.98

209

Table 19A

Soybeans alone: analysis of variance of percent reduction in growt h caused by atrazine (Table 1 9, Chapter 3)

Source

Replicate

Soil

(S)

Atrazine (A)

SxA

Error

Total'

C.Y. ( % )

R 2

DF

2

72

176

267

8

9

Percent reduction in top growt h dry mass

MS F value PR

>

F

23

6720

7230

445

28

0.81

234.46

252 .25

15.52

0.4484

0.0001

0.0001

0 .

0001

15

0 .

97

'Two missing values were recorded due to unsatisfactory emergence at two separate treatment combinations.

Table 20A

Sunflower a lon e: analysis of variance of percent reduction in growth caused by atrazine (Table 20 , Chapter 3)

Source

Replicate

Soil

(S)

Atrazine (A)

SxA

Error

Total'

C

R

.

2

Y.

( % )

DF

2

9

9

81

192

293

Percent reduction in seed yield

MS

89

24275

16056

682

53

13

0.98

F value

2.32

627.54

415.06

1 7.65

PR

>

F

0.\010

0.0001

0.0001

0.0001

'Six missing values were r ecorded because of unsatisfactory emergence at six separate treatment combinations .

210

Table 21A Analysis of variance of percent reduction in growth caused by atrazine to grain sorghum (Table 21, Chapter 3)

Source

Replicate

Soil (S)

Atrazine (A)

SxA

Error

Total c.Y.

(%)

R 2

DF

64

160

242

2

8

8

Percent reduction in top growth dry mass

MS F value PR> F

24

6981

13345

338

26

0.90

260.25

497.45

12.63

0.4104

0.0001

0.0001

0.0001

13

0.97

211

Table 22A Analysis of variance of percent reduction in growth caused by atrazine to the test plant oats, 35 days after herbicide app l ication (Figure 3, Chapter 4; data given in Table 2B)

Source

Replicate

Locality (L)

Atrazine (A)

LxA

Error

Total'

C.Y

.

(%)

R 2

DF

4

9

4

36

181

234

Percent reduction in top growth dry mass

MS F value PR

>

F

IOI.3

6450.4

45356.8

570.3

116.9

0.87

55.16

387.89

4.88

0.4852

0.0001

0.0001

0.0001

22

0.92

'Two replicates at locality no .

8 , and one at l ocality no . 10 were discarded due to unsatisfactory p l ant stand.

Table 23A Analysis of variance of percent reduction in growth caused by atrazine/atrazine residues to the test plant oats , 182 days after herbicide application

(Figure 4, Chapter 5; data given in Table 3B)

Source

Replicate

Locality (L)

Atrazine (A)

LxA

Error

Total'

C .

Y.

(%)

R 2

6

4

24

125

163

DF

Percent reduction in top growth dry mass

MS F value PR

>

F

4 840.5

2852.4

12972 .

3

936.7

2 .

77

9.40

42.84

3.09

0.0301

0.0001

0.0001

0.0001

303.4

74

0.71

'Two replicates were discarded at locality no. 4 due to unsat i sfactory plant stand. In addition , one m i ss i ng value was recorded.

212

Tab

l

e 24A

Analysis of variance of perce n t reduction in growth caused by atrazine/atrazine residues to the test plant oats, 365 days after herbicide application

(Figure 5, Chapter 5; data given in Table 4B)

Source

Replicate

Locali ty (L)

Atrazine (A)

LxA

Error

Total'

C.Y.

(%)

R 2

DF

4

24

4

6

126

164

Percent reduction in top growth dry mass

MS F value

PR

>

F

2372.5

2401.7

527.6

279.7

513.4

4 .

62

4 .

68

1.03

0.54

0 .

0016

0.0002

0.3957

0 .

9572

50

0.33

'Ten missing values were recorded because data from one replicate at each of the no.

4 and no. 6 localities were discarded due to unsatisfactory plant stand .

213

Ta

bl

e 25A

Analysis of variance of percent reduction in sunflower yield caused by residues of the recommended rates of atrazine applied 12 months previously (Table 27 ,

Chapter 6)

Source

Replicate

Soil

Error

Total c.Y. (%)

R 2

DF

4

6

24

34

Percentage yield reduction

MS

14

396

22

F value

0.6

18.2

40

0.82

PR

>

F

0.6360

0.0001

Table 26A

Analysis of variance of percent reduction in sunflower yield caused by residues of the recommended rates of atrazine applied 24 months previously (Table 28 ,

Chapter 6)

Source

Replicate

Soil

Error

Total

C.Y. (%)

R 2

DF

4

5

20

29

Percentage yield reduction

MS F value

4

676

6

0.7

116.1

45

0.96

PR

>

F

0.6083

0.0001

2 14

Table 27 A

Analy s i s o f varia n ce of pe r cen t reductio n i n seed y i e l d of dry beans ca u sed by resid u es of a ll a tr azine r ates app l ied 12 m o nth s pr ev i o u s l y ( D ata appear i n Ta b le 5B)

Sou r ce

R ep li ca t e

Loca l i t y (L)

Atraz in e (A)

LxA

E rr or

Tota l '

C.Y.

R 2

(%)

D

4

7

5

F

35

182

233

Percen t red u ctio n i n seed y i e l d

M S

22.99

5 4 3.0

1

17 4 .48

33 .

11

1 5 .4

9

78

0.68

F va lu e

1 .48

35 .

04

11.26

2.

1 4

P R

>

F

0.2089

0 .

0001

0.000

1

0.0007

'Six m issing values were r eco r ded - five of w hi c h were d u e to on l y fou r replicates being u sed a t Kroo n stad as a res u lt of flooding in t hat part of the trial at one stage .

Ta bl e 2 8A

Ana l ys i s of var i ance of percent r ed u ction in p l ant stand o f dry beans ca u sed by residues of a ll at r azi n e r ates ap pli ed 1 2 m o n t h s p r evious l y (Data appear in Table 6B)

Source

Replicate

Loca l i t y (L)

At r az i ne (A)

LxA

Error

Tota l ' c

R

.

2 y .

(%)

DF

4

7

5

35

1 82

233

Perce n t r ed u ct i o n in sta n d

M S

27 .

38

17 .

77

1 0.72

5.74

15.49

F value

3 .1

6

2.05

1.

24

0.66

1 92

0.23

' S i x m i ss i ng va l ues were r eco r ded (see foot n ote Tab l e 27A) .

P R

>

F

0 .

0 1 54

0 .

0512

0 .

2936

0.925

1

215

Ta bl e 29A

Analysis of variance of percent reduction in seed yield of sunflower caused by residues of al l atrazine rates applied 12 months previously (Data appear in Table 7B)

Source

Replicate

Locality (L)

Atrazine (A)

LxA

Error

TotaP c.Y

R 2

.

( % )

DF

4

6

5

30

162

207

Percent reduction in seed yield

MS

F value

30.1

2629.4

742.8

42.9

23.0

1.31

1 14.15

11.26

1.86

38

0.85

PR

>

F

0.2703

0.0001

0.0001

0.0077 lTwo missing values were recorded as a result of unsati s factory plant emergence in two plots.

Tab l e 30A

Analysis of variance of percent reduction in plant stand of sunflower caused by residues of all atrazine rates applied 12 months previously (Data appear in Table 8B)

Source

Replicate

Locality (L)

Atrazin e (A)

LxA "

Error

Total

I c.Y.

R 2

( % )

DF

4

6

5

30

1 62

207

Percent reduction in stand

MS

29 .

58

I 071.20

254 .

99

40.79

28.31

F value

1.04

37.84

9.01

1.44

86

0 .

66

PR

>

F

0.3858

0 .

0001

0.0001

0.0788 lTwo missing values were recorded as a result of unsatisfactory emergence .

216

Table 31A Analysis of variance of percent reduction in seed yield and plant stand of dry beans caused by residues of atrazine that was applied 24 months previously at

Warmbad (Data appear in Table 9B)

Source

Replicate

Atrazine

Error

Total'

C .

Y .

(%)

R 2

DF

4

5

15

24

MS

Seed yield

F value

8.33

621.63

13.25

0.63

46.91

PR > F

0.6494

0.0001

Source

Replicate

Atraz i ne

Error

DF

4

5

16

25

MS

115.27

1296.14

73.07

10

0.98

P l ant

stand

F value

1.58

17.74

PR> F

0.2283

0.0001 c.Y

R 2

.

(%) 38

0.88

'Five missing values recorded for yield data as a result of flooding across replicates on one side of the trial.

2 Four missing values recorded because plants in only one of the plots mentioned above cou l d still be counted.

217

Table 32A Analysis of variance of percent reduction in seed yield and plant stand of su nflower caused by residues of atrazine that was applied 24 months previou s ly (Data for yield and stand are given in Table lOB and Table liB, respectively)

Source

Replicate

Locality (L)

Atrazine (A)

LxA

Error

Tota l '

C.Y.

( %)

R 2

Source

Replicate

Locality (L)

Atrazine (A)

LxA

Error

Tota1

2

C.

R 2

Y . ( % )

DF

4

5

5

25

1 36

175

DF

4

5

5

25

137

176

MS

6.6

4933 .

0

30.3

31.0

3.9

MS

80.6

9 1.9

83.0

21.7

28.9

Seed yie ld

F value

36

0.98

Plant stand

25

0.31

1.7

1277.6

7.8

8.0

F value

2.79

3 .

1 8

2.88

0.75

PR

0.1535

0.0001

0.0001

0.0001

PR

>

F

>

F

0.0288

0.0095

0.0168

0.7931

'Four mi ssi ng va lu es were r eco rded three as a result of un sat i sfactory emergence and one due to bird damage.

~ hree mi ssi ng va lue s were recorded .

Source

Soil (S)

Soil water (W)

Temperature (T)

Atrazine (A)

S x

W

SxT

SxA

Wx T

Ax W

AxT

S x

W x

T

S x

W x

A

SxTxA

SxWxTxA

Error

Total

C.y.

(%)

218

Table

33A

Analysis of variance of percent atrazine

remaining in two

soils 30

days

after

incubation under

different soil water and

temperature

levels (Table 29 , Chapter

7)

OF

2

2

4

2

2

4

2

2

2

2

1

8

36

71

4712.6

1352.1

205.2

9.0

33.3

100.5

77.1

86.3

33.3

3.4

15.1

91.9

26.9

15.5

9.6

Percent atrazine in soil 30 d.a. t.

MS

F value

PR

>

F

492.28

141.24

21.44

0.94

3.47

10.49

8.05

9.01

3.47

0.36

1.58

9.60

2.81

1.62

0.0001

0.0001

0.0001

0.3379

0.0417

0.0003

0.0074

0.0001

0.0417

0.7030

0.2010

0.0005

0.0735

0.1546

3

0.96

Source

Soil (S)

Soil water

(W)

Temperature (T)

Atrazine (A)

S x W

SxT

SxA

Wx T

AxW

AxT

S x W x T

S x W x A

SxTxA

SxWxTxA

Error

Total

C .

Y. ( % )

R 2

219

Tab l

e 34A Analysis of variance of percent atrazine remaining in two soils 60 days after incubatio n under different soil water and temperature levels (Table 30 , Chapter

7)

2

8

4

2

4

2

2

36

71

DF

1

2

2

2

2

Percent atrazine in soil 60 d .

a .

t.

MS

4736.8

6381.4

650.3

147.3

443.1

234.4

98.0

101.1

15.2

2.4

21.1

73 .

8

4.5

11.1

8.3

F value

569.38

767.04

78.16

17.71

53.26

28 .

17

11.78

12.16

1.83

0.28

2 .

54

8.87

0 .

54

1.33

PR

>

F

0.0001

0.0001

0.0001

0.0002

0 .

0001

0 .

0001

0.0015

0.0001

0.1753

0.7558

0 .

0568

0 .

0007

0.5869

0 .

2605

4

0.98

Source

Soil

(S)

Soil water (W)

Temperature (T)

Atrazine (A)

S x W

SxT

SxA

Wx T

Ax W

AxT

S x W x T

S x W x A

SxTxA

SxWxTxA

Error

Total

C.Y.

(%)

R 2

220

T a bl e 35A

Analysis of varia n ce of amount of atrazine remai ni ng in two soils 30 days after incubation under different soil water and temperature levels (Data given in Table

19B)

2

2

8

36

71

4

2

2

4

DF

2

2

2

2

0.3363

0 .

0458

13.860

0.1821

0.0311

0.2255

0.0173

0.0725

0 .

0054

0.0048

Atrazine r emaining in soil 30 d.a.t.

MS F value

PR >

F

1.1526

0.0717

0.0164

0.0040

0.0017

666.60

194.49

26.47

8015.49

105.29

17.97

130.45

9.98

41.95

3.13

2.76

41.48

9.46

2.30

0 .

0001

0.0001

0.0001

0.0001

0.0001

0 .

0001

0.0001

0.0001

0.0001

0.0560

0.0425

0.0001

0.0005

0.0423

3

0 .

99

Source

Soil (S)

Soil water (W)

Temperature

(T)

Atrazine (A)

S x W

SxT

SxA

W x T

AxW

AxT

S x W x T

S x W x A

SxTxA

SxWxTxA

Error

Total

C.Y.

(%)

R 2

221

Table 36A Analysis of variance of amount of atrazine remaining in two soils 60 days after incubation under different soil water and temperature levels (Data appear in Table

20B)

2

2

8

36

71

2

4

4

2

DF

2

2

2

2

Atrazine remaining in soi l 60 d.a. t.

MS F value PR

>

F

0.0219

0.1871

0.0126

0.0036

0.0547

0.0026

0.0027

1.1704

1.4603

0.1421

11.3129

0.1286

0.0486

0.2426

0.0015

774.56

966.39

94.06

7486.50

85.09

32.

1 7

160.59

14.46

123 .8

1

8.31

2.35

36.21

1. 74

1.78

0 .

0001

0.0001

0.0011

0.0724

0.0001

0.1893

0.1128

0.0001

0.0001

0.0001

0 .

0001

0 .0001

0 .

0001

0.0001

3

0.99

222

Table 37A Analysis of variance of fresh and dry mass of test plants seeded in the field at various stages after atrazine application (Table 31, Chapter 8)

Source

Day

Error

Total

C.V. (%)

R 2

DF

5

12

17

Fresh mass of top growth

MS

5086.6

25.5

F value

199.73

PR

>

0.0001

F

Source

Day

Error

Total

C.Y.

(%)

R 2

DF

5

12

17

10

0.98

Dry mass of top growth

MS

5040.9

19.4

F value

260.54

9

0.99

PR

>

0 .

0001

F

223

Table 38A Analysis of variance of percent reduction in top growth dry mass caused by atrazine to oats in so i l samples taken from different soil l ayers at I, 30, 60, 90 and

120 days after herbicide application (Table 32, Chapter 8)

Source

Day (D)

Layer (L)

DxL

Error

Total

C.Y.

(%)

R 2

Percent reduction in top growth dry mass

DF MS F value PR

>

F

4

3

6'

36

49

6133.2

422 .

1

470.4

19.0

322.01

22 .

16

24.70

0.000 1

0.0001

0.000 1

14

0.98

'Data for six treatment combinat i ons (day 11100-200 mm; day 11200-300 mm; day

11300-400

mm; day 30 / 300-400 mm; day 60/300-400 mm; day 90 / 300-400 mm) were not available for analysis because only certain soil layers were monitored at specific intervals.

Table 39A Analysis of var i ance of the estimated concentration of atrazine in soil samples taken from different soi l layers 1, 30, 60 , 90 and 120 days after herbicide application in the field (Table 32, Chapter 8)

Source

Day (D)

Layer (L)

DxL

Error

Total

C.Y.

R 2

(%)

DF

4

3

6'

36

49

Estimated atrazine concentration

MS

0.0219

0.0005

0.0009

0.0001

F value

229.81

5.65

9.26

29

0 .

97

PR

>

F

0.000 I

0 .

0028

0.9196

'Data for six treatment combinations (day 11100-200 mm; day 11200-300 mm; day

1 / 300-400 mm; day 30 / 300 400 mm; day 60 / 300 400 mm; day 90 / 300 400 mm) were not available because only certain soil layers were monitored at specific intervals .

Source pH

Day (D)

Atrazine (A) pH x D pH x A

DxA pH x D x A

Error

Total

C.Y.

( % )

R 2

224

Ta bl e 4 0 A

Analysis of variance of percent reductio n in top growt h dry mass of oats caused by atrazine residues at diffe r ent soil pH levels (Table 34 , Chapter 9)

DF

5

4

20

5

4

20

120

179

Percent reduction in top growth dry mass

MS

10170

20830

13187

676

120

448

230

64

F value

157.28

322.14

203 .

95

10.45

1.86

6.94

3.56

PR

>

F

0.0001

0 .

0001

0.0001

0 .

0001

0.1064

0.0001

0.0001

17

0.95

225

Tab l

e 41A Analysis of variance of percent damage caused to oats by the lowest range of atrazine rates used to obtain dose-response curves for three soils (Data in Table 21B)

Source

Soil (S)

Atrazine (A)

SxA

Error

Total

C.Y.

(%)

R 2

DF

2

7

14

48

71

Percent damage in top growth dry mass

MS F value

PR

>

F

1310.2

11216.0

177.6

16.2

80.7

691.1

10.9

0 .

0001

0.0001

0.0001

9

0.99

Table 42A

Analysis of variance of percent damage caused to oats by the first intermediate range of atrazine rates used to obtain dose-response curves for

12

soils

(Data in table 21B)

Source

Soil (S)

Atrazine (A)

SxA

Error

Total

C.Y.

(%)

R 2

DF

II

7

77

192

287

Percent damage in top growth dry mass

MS F value

PR

>

F

685

27223

71

20

33.40

1327.17

3.48

0.0001

0.0001

0 .

0001

8

0.98

226

Table 43A Analysis of variance of percent damage caused to oats by the second intermediate range of atrazine rates u sed to obtain dose-response curves for five soils

(Data in Table 21B)

Source

So il (S)

Atrazine (A)

SxA

Error

Total

C.

Y.

( % )

R

2

DF

24

70

4

6

104

Percent damage in top growth dry mass

MS F value PR

>

F

2092

12755

301

41

51.46

3 13.75

7.42

0 .

0001

0.0001

0 .

0001

17

0.97

Table 44A Analysis of variance of pe r cent damage caused to oats by the highe s t range of atrazine rates u sed to obtain do se -r espo n se curves for five soi l s (Data in Table 21 B)

Source

Soi l (S)

Atrazine (A)

SxA

Error

Tota l

C.Y. ( % )

R

2

OF

4

6

24

70

104

P e r ce nt damage in top growth dry mas s

MS F value PR

>

F

962

1 86 1 7

104

25

39.12

756.72

4 .

21

0.0001

0.0001

0 .

0001

9

0.98

227

Table 45A

Analysis of variance of estima t ed amounts of residual atrazine which were avai l ab l e to the test plant at certai n intervals after application of the herbicide (Tab l e

36 , Chapter 9)

Sou r ce

Soil (S)

Days (D)

S x D

Error

Total

C.V. ( % )

R 2

DF

24

5

120

300

449

0

Concen trati on (mg kg · l

)

.

MS

0068

0.3063

0 .

00 1 5

0.0003

F value

22 .

37

1002.47

5 .

04

1 7

0.95

PR

0 .

>

0001

F

0.0001

0 .

0001

Table 46A

Stepwise procedure for depend e nt variab l e (atrazine half-life)

Variable entered

In sequence

[pH] '

( r2= 0 .

6938)

%C

(R

2

=0.8270)

[C Eq'

(R

2

= 0 .

8431)

Parameter Standard

Variab l e e s timate e r ror

Inter c ep

[pH] 2

Intercep

Int

% C

[pH] 2 e rcep

% C

[pHf

[CEC] 2

10.6015

1.7368

-2 .

2907

20 .

8124

I. 7752

2.9517

19 .

0224

1.6246

0.0060

9.1

0 .

2

7.6

5 .

0

0 .

2

8.2

5 .

0

0 .

2

0 .

0

R e m ove d:

[ CEC]'

1.36

52.13

0.09

16.93

91.96

0.13

14.04

61.35

2 .

17

F-v a lu e Prob > F

0 .

2560

0.0001

0 .7

678

0 .

0005

0 .

0001

0.7248

0.0012

0.000

1

0.1558

APPENDIX B

228

Table IB

Composition of the Nitsch (1972) nutrient solution used in certain pot experiments

Concentration

Combination'

A

Sa l t

KN0

3

KH , PO.

610

310

B

C

MgSO •. 7H , O

(NH.),sO.

Ca(N0

3

) , .4H

, O

EDTA.Na

, Fe

610

310

2440

60

D KCL

H

3

B0

3

MnSO •. H , O

ZnSO •. 7H , O

(NH.).M0

7

O , •. 4H , O

CuSO •. 5H , O

H

2

SO .

6. I

6.7

3.8

0.61

6.1

0 .

31

0.31 cm

3

'A , B , C and D were made up separately to 10 L using deionised water. Once dissolved, these combinations were combined and made up to 2219 L using deionised water.

229

Table 2B Percent reduction in the top growth dry mass of the test plant oats at 10

sites, 35 days after atrazine application (ANDY A in Table 22A)

Locality

Bapsftn. A

Bapsftn. B

Ermelo

Kroonstad

Nelspruit

Pretoria

Standerton

Yentersdorp

Warmbad A

Warmbad B

LSD

T

(0.05)

0.031

Atraz i ne rate (kg ai ha ')

0.062 0.125 0.250 0.500

%

4.4

5.5

8.8

16.4

24.9

15.5

1.3

30.2

16.3

8 .

0

%

13.8

12.1

13.2

46.1

62.9

30.7

18.5

%

19 .

9

23.9

34.8

77.4

99.8

63.0

19.3

%

28.5

60.2

62.0

97.4

100.0

85.1

64.2

35.0

19.2

8.2

62.4

23.8

23 .

0

90.7

53.3

62.6

Locality x Atrazine rate

=

27.3

%

72.2

81.9

94.4

99.7

100.0

94.4

87.4

97.9

82.6

88.2

Mean

27 .

7

36.7

39 .

0

67.4

77.5

57 .

8

38.1

63.2

39.0

38.0

Table 3B Percent reduction in the top growth dry mass of the test plant oats at seven

sites, 182 days after atrazine appl i cation (ANDY A in Table 23A)

Locality

Bapsftn. A

Bapsftn. B

Ermelo

Kroonstad

Pretoria

Warm bad A

Warmbad B

LSD

T

(0 .

05)

Atrazine rate (kg ai ha ')

0.031 0 .

062 0.125 0 .

250

%

13.2

5.8

2.2

3.4

-3.8

10.3

8.2

%

8.8

9.8

0.0

4.4

14 .

8

10.3

18.0

%

1.5

17.4

10.4

21.4

33.6

24.3

29.2

%

11.2

30.0

8 .

8

38.2

38.6

36.0

27.8

Locality x Atrazine rate

=

43

0.500

%

9.0

62.2

12.8

87.2

75.8

85 .

7

62.2

Mean

9.0

25.0

6.8

30.9

31.8

33.3

29 .

1

230

Table 4B

Percent reduction in the top growth dry mass of the test plant oats at seven sites , 365 days after atrazine application (ANOY A in Table 24A)

Locality

Bapsftn. A

Bapsftn. B

Erme l o

Kroonstad

Pretoria

Warmbad A

Warmbad B

LSD

T

(0 .

05)

0.031

%

-7.3

6.7

0.3

4.5

11.6

8.1

-37.4

Atrazine rate (kg ai ha ')

0.062 0.125 0.250

%

-1.2

5.8

-10.9

-9.4

II. I

7 .1

-27.8

%

0.8

4.6

1.

0

-3 .4

10 .5

18.5

-21.3

Locality

=

22

%

-1.2

5.9

-0.0

-4.0

15.6

6.5

-0.6

0.500

%

2.1

11.0

8.5

-9.7

11.3

18.4

4.4

Mean

-1.4

6.8

-0.6

4 .4

12.0

11.7

-16.5

231

Table SB

Dry bean yield and percentage reduction in yield 12 months after atrazine application in maize (ANOVA for percentage data appears in Tab l e 27A ; data for recommended rate only are presented in Table 27 , Chapter 6)

Locality

Carltnv.

Baps. A

Baps. B

Vryheid

Pta. A

Pta. B

Delmas

Krnstad.

Control kgl

0 .

483

0.520

0.478

0.232

0 .

748

0.808

0.279

0.729

% 2

3

-2

0

2

4

0

-I

I kg

0.466

0.518

0.483

0.224

0.766

0.808

0.273

0.723

2

Atrazine rate number

3 4

%

0

2 kg

0.481

0.511

0.475

% kg

9 0.442

I

5 0.495

4 0.461

% kg

4 0.465

7 0.485

I 0.472

10

-2

4

0.210 10 0.208 17 0 .

192

0.760

-I

0.817

0.268

0.744

0.800

5 0.264

2 0.764

0 .

802

8

0 .

258

2 0.716 3 0 .

705 5 0.695

19

3

-I

II

%

3

7

-2

8

5 kg

0.468

%

8

0.485 6

0.485

-2

0.188

21

0.772

0

0.819 2

0 .

249 17

0.674 9

6 kg

0.447

0.487

0.486

0 .

183

0 .

747

0.791

0 .

231

0.664

'Kilogram seed per 4 m row section. Formula for transformation to ton ha "

=

111.1[25(kg seed 4 m · I)] / IOOO.

2Percent reduction in yield relative to control (0 atrazine).

3 Different atrazine r a tes were used in each trial. Rates used appear in Table 26 , Chapter 6. Underlined values were measured at the recommended rate for each locality.

NB The trial at Warmbad was terminated when 90-100 % of seed l ings died soon after emergence on all p l ots treated with atrazine.

232

Tab l

e 6B Dry bean stand and percentage reduction in stand 12 months after atrazine application in maize (ANOY A for percentage data appears in Tab l e 28A)

Locality

Carletnv.

Baps . A

Baps. B

Yryheid

Pta . A

Pta. B

Delmas

Krnstad.

Control no.l

42

37

35

32

47

45

40

3 3

% 2 no.

0

0

0

0

3

0

0

0

47

45

40

42

36

35

32

33

%

-2

0

3

2

3

0

3

0

2

41

36

35

31

33 no.

48

45

39

Atrazine rate number

3

2

0

3

0

-3

%

-2

4

5 no.

48

43

38

41

37

36

32

34

0

3

0

3

3

%

0

2

0

4 no .

47

44

40

42

36

35

31

32

0

3

0

3

0

%

0

0

0

5 no.

47

45

40

42

36

35

31

33

%

0

2

3

0

3

0

3

3

6

42

36

35

31

32 no.

47

44

39 lNumber of p l ants per 4 m row section mon i tored.

2Percent reduction in stand relative to control.

3Different atrazine rates were used at each locality .

Rates used are given in Table 26 (Chp. 6) .

Underlined values were measured at recommended rates for each locality.

233

Ta bl e 7B

Su n flower yield and pe r centage reduction i n yie l d 12 mo n t h s after atrazine application in maize (ANOVA for percentage data appears in Table 29A; percentage data for recommended rates only appear in Table 27 , Chapter 6)

Locality

Carltnv.

Baps . A

Baps. B

Vryheid

Pta. A

Pta . B

De l mas

Contro l kg'

1.293

1.328

1.

526

1.340

2.107

1.458

1 .

261

% 2

0

13

-6

12

14

10

10

I kg

1.117

1.190

1.373

1.340

1.824

1.540

1.106

Atra z ine rate number

%

18

17

15

11

-7

15

2

1.103

1.296

1.330

1.881

1.558

1.073

3 4 kg

1.063

I

% kg

I

% kg

%

21 1.025 21 1.

016 25

5

19

14

2

13

-3

1 9

1.078 21

1.305

17

1.050

1.270

23

13

1.315 1.326

1.844 16 1.770

20

1.505 3 1.411

-I

1.027 16 1.064 17 kg

%

0.972 37

1.022 35

1.32

1 18

1.327 5

1.683 21

1.

467 4

1.

043 24

6 kg

0.818

0 .

858

1.247

1.274

1.666

1.395

0 .

961

' Kilog r am seed per 4 m row section. Formula for transformation to ton ha "

=

1 11.1[25(kg seed 4 m · ') ] I1000.

'Percent reduction i n yie l d relative to control (0 atrazine) .

'Different atrazine rates wer e used in each trial. Rates u s ed appear in Table 26 , Chapter 6. Underlined values were measured at the recommended rate for each locality .

NB The tria l a t Warmbad was terminated when 90-100 % of seedlings died soon after emergence on all plots t h at had been treated with at r a z ine.

Sunflower was not monitored at Kroonstad due to unsati s factory emergence which was clearly not l inked to atrazine damage .

234

Table 88

Sunflower stand and percentage reduction in stand 12 months after atrazine appl i ca tion in maize (ANOYA for perce n tage data appears in Table 30A)

Locality

Carletnv

Baps. A

Baps. B

Yryheid

Pta . A

Pta . B

Delmas

.

Contro no!

16.0

14.2

1 5.2

14.2

14.4

13.6

12.4 l

%

6

9

0

0

7

3

2

2 no .

15.0

12.8

15.2

14.2

13.4

13.2

12.2

%

13

0

3

3

2

6

1

2 no .

14.0

13.4

15.0

14 .

2

14.0

13.2

1 2 .

2

Atrazine rate number'

3

-

%

15

17

1

3

3

3 no.

13.6

1l.8

1 5.0

14.4

1 4 .

0

13 .

2

1 2.

0

%

16

14

0

0

3

3

3

4 no.

1 3.4

12.2

15.2

14.2

14.0

1 3.2

12 .

0

%

18

18

3

8

0

2

5 no.

1 3 .

2

1l.

6

14.8

14.0

13.2

13.6

1 2.2

%

26

11.8

18

11

4

6 no.

1l.6

13.6

13 .

6

6 13.6

6

1 2 .

8

6 1l.6

'N umber of plants per 4 m row segment monitored .

2Percent reduction in stand relative to control.

3Different atrazine rates were used at each l ocality. Rates used are g iven in Table 26 (Chp. 6). Underlined values were measured at recommended rates for each locality.

235

Tab l e 9 B

Dry bean yield and percentage reduction in yield 24 months after atrazine application in maize at Warm bad (ANOY A for percentage data appears in Table

31A)

Atrazine rate kg ai h a '

0

1.8

2.1

2.42

2 .

7

3.0

3 .

3

LSD

T

(0.05)

CY %

23

21

38

42

48

50

Yield (4 m row segment)

%'

kg

0.197

0 .

151

0 .

155

0 .

121

0.1

1 4

0.103

0 .

098

0 .

015

6

Plants (4 m row segment)

%

-

11

4

'

10

41

35

18 no.

38 .

0

33 .

8

36.6

34 .

2

22.2

24 .

6

31.2

15 .

7

25

'Percent reduction in yield or stand compared to the controls (0 atrazine). ANOY AS for percentage data appear in Table 31 A.

2Recommended herbicide rate

=

2.4 kg ai ha '.

NB Warm bad was the only site at which significant damag e to dry beans was observed 12 months previous l y .

236

Table lOB

Sunflower yield and percentage reduction in yield 24 months after atrazine application in maize (ANOVA for percentage data appears in Table 32A; percentage data for recommended rates on l y are given in Table 28, Chapter 6)

Locality

Control kg'

1.200

1.050

1.265

1.800

1.560

1.419

%

0

0

-2

0

28

2 kg

1.195

1.046

1.247

1.833

1.555

1.024

Atrazine rate number

-

%

2

0

1

29

3 4 kg

1.180

1.047

% kg

1.188

0 1.053

1.251 1 1.256

1.816 -1 1.815

%

1

1.546

0

1.555 -1

1.008 38 0.872 40

5 kg

1.187

1.037

1 .247

1.789

1.572

0.845 41

0

0

%

0

0

1

6

Carltnv.

Baps.

Baps.

Pta . A

A

B

Delmas

Warmbad

% 2 kg

1 1.192

2

0

-2

1.032

1.260

1.839

2

29

1.524

1.007

'Kilogram seed per 4 m row section. Formula for transformation to ton ha · '

=

111.1[25(kg seed 4 m · ')]Il000.

2Percent reduction in yield compared to control (0 atrazine).

3 Different atrazine rates were used in each trial. Rates used appear in Table 26 , Chapter 6. Underlined values were measured at the recommended rate for each locality. kg

1.200

1.051

1.257

1.806

1.563

0.843

237

Table 11B

Sunflower stand and percentage reduction in stand 24 months after atrazine application in maize (ANOYA for percentage data appears in Table 32A; percentage data for recommended rates only appear in Table 28, Chapter 6)

Locality

Car l etnv.

Baps . A

Baps . B

Pta. A

De l mas

Warmbad

Contro no.1

1 4 .

0

14 .

0

14.0

1 4.0

1 4.0

14.0 l

%

3

0

3

0

0

2

1

14

1

1 no .

13.6

14

3

.

.

.

0

3.6

0

4.0

9

%

0

0

0

0

0

3

2 no.

14.0

14.0

1 4 .

0

14.0

1 4 .

0

13 .

6

Atrazine rate number"

3

%

0

3

0

6

0

6 no.

14.0

13 .

6

14.0

13.2

14 .

0

13.2

%

3

3

3

3

6

14

4 no.

13

13

13.6

13.6

13

.

.

.

6

6

2

12.0

%

0

0

0

0

0

7

5 no.

14.0

14.0

14.0

14.0

14.0

13.0

%

0

0

3

3

3

4

6 no.

14.0

14.0

13.6

13.6

13.6

13.4

INumber of plants per 4 m row segment monitored.

2Per ce nt reduction in stand re l ative to control.

3D i fferent atrazine rates were used at each l ocality . Rates used are given in Tab l e 26 (Chp. 6) . Underlined values were measured at recommended rates for each locality .

238

T a bl e 12B

Rai n fal l an d m ean daily maxi mum an d mini m u m t e mp e r a tu res r ecorded at

K r oo n stad fo r the pe ri od afte r atrazi n e a ppl icat i o n o n 27 N ovembe r 1 987 unti l th e seedi n g of dry beans a n d s u nflower on 3 December 1988 (C h apter 6)

Period

27 N ov-31 Dec 1987

J an . 1 988

Feb.

Mar.

Ap r.

May

J un .

J u l.

A u g.

Sept.

Oc t.

Nov.

30 Nov 3 Dec

Tota l rainfall

Rainfa ll ' (mm)

56

1 7 (99)

89 (81)

220 (96)

1 26 (55)

1 5 (19)

1 2 (6)

(6)

(17)

4 5 (33)

152 (67)

93 (80)

23

850 (632)

Te m perat u re ( 0 C)b

Max.

29

32 (28)

28 (27)

27 (26)

22 (22)

2 1 (20)

16 ( 1 6)

19 (17)

22 (20)

23 (24)

24 (26)

26 (27)

25

Mi n .

15

16 (15)

17 (15)

15 (13)

9 (9)

3 (5)

I

(I)

-1 (0)

2 (2)

7 (8)

10 (II)

1 2 (13)

1 3

'Longt e r m average fo r th e mon t h l y t ota l appea r s i n pare n t h esis. bLo n g-te r m mean dai l y max i m u m a n d mi n i m um tem p e r atures a p pear i n pare n t h esis.

' Long -t e rm year l y ra i nfall (I J a n -31 Dec) a p pears i n pa r en th es i s.

239

Tab l

e 13B Rainfall and mean daily maximum and minimum temperatures recorded at

Vryheid for the period after atrazine application on 23 November 1987 until the seeding of dry beans and sunflower on 5 December 1988 (Chapter 6)

Rainfall' (mm)

90

95 (133)

95 (138)

96 (95)

66 (37)

3 (10)

30 (25)

23 (7)

75 (24)

20 (45)

135 (106)

93 (l00)

51

872 (869)

Max.

27

27 (26)

25 (25)

24 (25)

20 (23)

22 (22)

18 (19)

20 (19)

22

(21)

22 (22)

21 (23)

21 (23)

22

Temperature ( e qb

Period

23 Nov-31 Dec 1 987

Jan. 1988

Feb .

Mar.

Apr.

May

Jun.

Jul.

Aug .

Sept.

Oct.

Nov.

30 Nov-5 Dec

Total rainfall

' Long-term average for the monthly total appears in parenthesis. bLong-term mean daily maximum and minimum temperatures appear in parenthesis.

' Long term yearly rainfall (I Jan-31 Dec) appears in parenthesis .

Min.

17

16 (15)

16 (IS)

16 (15)

12 (12)

9 (10)

7 (7)

6 (6)

9 (8)

.

11

(10)

II

(11)

12 (12)

14

240

T

ab

l

e 14B

Rainfall and mea n maximum and minimum temperatures recorded at

Car l eton ville for the period after atrazine application on I December 1987 until the seeding of dry beans and sunflower on 6 December 1988 (Chapter 6)

Month

Dec. 1987

Jan. 1988

Feb.

Mar.

Apr.

May

Jun.

Jul.

Aug.

Sept.

Oct.

Nov.

30 Nov-6 Dec

Total rainfall '

Rainfall ' (mm)

110 (109)

45 (120)

50 (78)

113 (79)

32 (56)

30 (12)

13

(7)

2 (3)

2 (7)

113 (19)

84 (71)

46 (89)

8

648 (665)

Temperature ( 0 C)b

Max.

27 (27)

29 (27)

27 (27)

26 (25)

22 (23)

21 (20)

17 (17)

19

(18)

22 (20)

27 (24)

24 (25)

25 (26)

23

Min.

18 (14)

16 (14)

16 (14)

14 (12)

9 (8)

3 (3)

0 (0)

-I (0)

3 (2)

8 (7)

II (10)

13 (13)

14

' Long-term average for the monthly total appears in parenthesis . bLong-term mean daily maximum and minimum temperatures appear in parenthesis.

' Long-term yearly rainfall (I Jan 31 Dec) appears in parenthesis .

241

Table 15B Rainfall and mean daily maximum and minimum temperatures recorded at

Delmas for the period after atrazine application on 1 December 1987 until the seeding of dry beans and sunflower on 6 December 1988 (Chapter 6)

Period

Dec. 1987

Jan. 1988

Feb .

Mar.

Apr.

May

Jun.

Jui.

Aug.

Sept.

Oct.

Nov.

30 Nov-6 Dec

Total rainfall'

Rainfall ' (mm)

86 (91)

89 (94)

48 (75)

77 (80)

25 (28)

2 (4)

18 (6)

7

(1)

0 (5)

55

(42)

81

(72)

20 (103)

7 (91)

515 (607)

Temperature ( o qb

Max.

26 (26)

28 (27)

26 (26)

26 (25)

22 (23)

21 (21)

17 ( 17)

19 (18)

21 (20)

21 (37)

23 (24)

24 (25)

25

(26)

Min .

13 (13)

15 (14)

14 (13)

13

(11)

8 (7)

2 (2)

I (0)

-I (-I)

(I)

7

(7)

10 (10)

II (II)

13 ( 13)

' Long-term average for the monthly total appears in parenthesis. bLong-term mean daily maximum and minimum temperatures appear in parenthesis.

' Long term yearly rainfall (I Jan-31 Dec) appears in parenthesis.

242

Table 16B Rainfall and maximum and minimum temperatures recorded at Pretoria for the period after atrazine application on 10 November 1987 and the seeding of dry beans and sunflower on

15 November 1988 (Chapter 6)

Period

IO Nov-30 Nov 1987

Dec. 1987

Jan. 1988

Feb.

Mar .

Apr.

May

Jun.

Jul.

Aug.

Sept.

Oct.

I Nov-IS Nov

Total rainfall '

Rainfall' (mm)

54

84 (110)

64

(133)

37 (77)

138 (84)

78

(49)

0 (II)

9 (4)

3 (2)

0 (6)

34 (21)

70 (69)

23

594 (668)

Temperature ("C)b

Max .

26

28 (28)

30 (28)

28

(27)

27 (26)

24 (23)

22 (21)

18 (18)

20 (19)

23

(21)

25 (25)

25 (26)

26

Min.

15

18

(16)

18

(17)

17

(17)

16

(16)

12 (12)

9 (8)

7 (4)

4 (4)

9 (7)

11 (11)

13 (14)

14

'Lo ng-term average for the monthly total appears in parenthesis. b Long -te rm mean daily maximum and minimum temperatures appear in parenthe sis.

' Long-term yearly rainfall (I Jan 31 D ec) appears in parenthesis.

243

Tab l e 1 7

B Rainfall and maximum and minimum temperatures recorded at Bapsfontein for the period after atrazine application on

13

November 1987 unti l the seeding of dry beans and sunflower on 16 November 1988 (Chapter 6)

Period

13 Nov-30 Nov 1987

Dec. 1987

Jan . 1988

Feb.

Mar.

Apr.

May

Jun .

Jul.

Aug .

Sept.

Oct.

I Nov-16 Nov

Total rainfall '

Rainfall' (mm)

53

105 (102)

1 00 (139)

47 (108)

129 (89)

77 (38)

2 (5)

20

(14)

4 (6)

0

(6)

69 (34)

70 (76)

170

846 (739)

Temperature ( 0 C)b

Max.

24

27 (26)

29 (27)

27 (26)

26 (25)

22 (23)

21

(20)

17 (17)

19 (18)

21 (24)

23 (23)

24 (25)

25

Min.

12

14 (13)

IS (14)

14 (13)

13

(12)

9 (8)

4 (4)

(I)

2 (I)

5

(4)

9 (7)

9 (10)

8

' Long term average for the monthly total appears in parenthesis. bLong-term mean daily maximum and minimum temperatures appear in parenthesis.

' Long-te r m yearly rainfall

(I

Jan-31 Dec) appears in parenthesis .

244

Tab l

e 18B Rainfall and the mean daily maximum and minimum temperature recorded at Towoomba for the period after atrazine application on 3 December 1987 until the seeding of dry beans and sunflower on lO December 1988 (Chapter 6)

Period

3 Dec-31 Dec 1987

Jan. 1988

Feb .

Mar.

Apr.

May

Jun.

Jui.

Aug.

Sept.

Oct.

Nov.

I Dec lO Dec

Total rainfall '

Rainfall ' (mm)

161

39 (113)

88 (87) lO7

(76)

43 (37)

0 (6)

63

(5)

0 (2)

(4)

36 (16)

133

(61)

18 (102)

21

710 (634)

Temperature ( 0 C)b

Max.

29

31 (29)

29 (29)

28 (28)

25

(26)

24 (23)

20 (20)

22 (21)

25 (24)

27 (27)

27 (29)

28 (29)

28

Min.

17

17 (17)

17 (16)

16 (14)

12

(11)

6 (6)

3 (3)

2 (3)

6 (5) lO

(lO)

13 (13)

14 (15)

16

'Long-term average for the monthly total appears in parenthesis. bLong-term mean daily maximum and minimum temperatures appear in parenthesis.

' Long-term yearly rainfall (1 Jan-31 Dec) appears in parenthesis.

245

Table

1

98 Effect of temperature and

s oil water on amount of atrazine (mg kg · !) remaining 30 days after application to a loamy sand and a clay soil (Chapter 7) - ANOY A in Table 35A

Soil type

Loamy sand

Clay

LSD

T

(0.05)

Atrazine rate

(mg kg

1

2

1

2

· !)

0

0.94

1.95

1.00

2.00

30/16 ° C fc mg kg · !

0.76

1.30

0.92

1.91

Temp . (day / night)

30 / 8 ° C

Soil water

2xfc 0 fc 2xfc 0 mg kg · !

0.71

1.28

0.95

1.93

0 .

92

1.93

1.03

2.00

0.72

1.27

0.87

1.95

0.74

1.35

0.93

1.93

Atrazine x Soil x Temp. x Water = 0.33

0.93

1.96

0.97

1.96

16 / 8 ° C fc mg kg · !

0 .

85

1.63

1.01

1.91

2xfc

0 .

81

1.58

0.96

1.96

246

Tab

l e

2

0B

Effect of temperature and s oil water on amount of atrazine (mg kg · ') remaining 60 days after application to a loamy sand and a clay soi l (Chapter 7) ANOYA in Tab l e 3 6A

Soil

Clay

LSD

T type

Loamy sand

(0 .

05)

Atrazine rate

(mg kg

I

2

I

2

· ')

0

0.86

1.81

0.96

1.95

30/16 ° C fc mg kg · '

0.45

0 .

90

0.73

1.

57

2xfc

0.45

0.9

0 .

7

1

1

1.53

Temp . (day / night)

30 / 8 ° C

Soil water fc 0 2xfc mg kg · '

0.82

1.87

0 .

96

1.96

0.60

1.06

0.74

1.59

0.5

0 .

1

99

0.63

1.50

Atrazine x Soil x Wate r= 0.08

0

0.94

1.9

1

0.94

1.96

16 / 8 fc

° C mg kg · '

0.70

1.33

0.80

1.72

2xfc

0.64

1.29

0 .

76

1.62

247

Table 21B Dose-response of the test plant (percent reduction in top growth d r y mass of oats) to different ranges of atrazine rates applied to a total of 25 soils (ANOYA for lowest range of rates in Table 41A; ANOYA for 1st intermediate range of rates in Table 42A ; ANOYA for

2nd intermediate range of rates in Table 43A; ANOY A for highest range of rates in Table 44A)

Exp. I : Lowest range of atrazine rates

Soil

Colby

Fairdale

Nelspruit

0.002

4

4

3

0 .

004

7

II

7

0.008

15

13

14

LSD

T

(P = 0.05)

Exp. II : First intennediate range of atrazine rates

Atrazine rate (mg kg I)

0.016

42

25

0.032

82

67

19 43

Soil x Atrazine rate = 13

0 .

064

89

75

58

Soil

Bethal

Bothaville

Ermelo A

Leeudoringst. A

Continued overleaf

0.0125

8

16

10

19

0.025

20

35

30

53

0 .

05

44

5 1

44

64

Atrazine rate (mg kg

I)

0.Q75

0.10

61

68

69

69

75

77

74

81

0.125

77

78

79

79

0 .

128

89

89

75

0.15

83

80

84

84

0.256

89

88

82

0.20

82

83

84

84

Mean

52

46

38

Mean

56

61

59

67

Table 2IB cont.

Leeudoringst. B

Nylstroom

Pretoria A I

Carleton ville

Ermelo B

Morgenzon

0.0125

19

9

7

Pretoria A2

Pretoria A3

5

7

16

20

45

40

59

58

68

71

Pretoria A4

Pretoria AS

9

4

4

26

13

41

38

24

52

52

43

69

70

56 Warmbad A

9

LSD

T

(P=0.05)

Exp. III: Second intermediate range of atrazine rates

Soil x Atrazine rate = 16

Atrazine rate (mg kg " )

Soil

0.Q25

0.05 0.10

0.15 0 .

20

3

4

-1

0.025

32

20

14

8

-5

7

0.05

49

45

38

33

2

23

0.D75

60

54

62

56

22

45

0.10

74

61

69

68

55

56

Continued overleaf

0.125

77

73

80

79

78

76

79

67

0.25

90

64

89

0.15

80

80

82

83

83

80

82

73

0.30

91

65

89

83

84

82

82

81

0.20

81

82

82

Mean

59

53

54

55

55

54

53

45

248

Mean

50

30

44

Tabl

e 2

IB c

o

n

ti

n

ued

Red h ill

Vryheid

1

7

12

7

LSD

T

(P = 0 .

05)

Exp. IV : H i g h est range of atrazine rates

Soil

Potgietersrus

Pretoria B

Roodeplaat

Utrecht

Warmbad B

LSD

T

(P = O.OS)

0.Q25

-4

4

8

4

0.05

21

10

37

8

4

22

21

43

18

56

29

Soil x Atrazine rate = 19

Atrazine rate (mg kg · l

)

0.10 0.15 0.20

44

27

45

66

42

64

38

27

56

58

Soil x Atrazine rate = 15

89

65

93

77

79

66

43

0 .

30

90

8 1

93

90

85

65

56

0.40

90

83

94

91

86

Mean

57

45

62

52

49

38

26

249

A PP ENDIX C

Co n tents: Dose-respo n se curves for 25 soi l s (Chapter 9 , Section B)

250

% Damage

1oor---~---------------------------------------'

80

y ,

1 5,6 • 50,02 log(' • 1000)

+

+ + r' ,

0,8846

60

4 0

+

20

+

+ o~~--------------------------------~

_20L---~----~--~---~-----L-----L----~

, 002 ,004 ,008 ,0 1 6 ,0 32 .064 .128 256

Alraz ine rale (mglkg)

Fig . I e Colby soi l

100

% Damage

y , -18,1) • 47,704 log(x • 1000)

80 r

2

, 0,919

60

+

+

40

+

20

+

0

-20

,002

.004 .008

,0 16 , 032 .064

Al r az ine rale (mglkg)

Fig . 2e Fairdale soil

+

.128 ,256

F i g ur es IC & 2C

Dose-response to atrazine in t he Co l by and Fairdale soi l s

%

Damage

1 oor---~---------------------------------------' y , -IS.55 + 41 .

41 l o g (x ' 1000) so r ' ,

0 .

957

+

60

+

4 0

20

+

+ or-~~--------------------------------~

_2oL-____

.002 .004 .

008 .016 .032 .

06 4

Al r az ine rate (mg/kg)

Fig. 3c Nelspruit soil

.12S .256

251

100

96 Dama g e

y , 23.76 + 51.53 l o g(, ' 1 00)

SO

, r

' 0.920

+

+

60

+

4 0

+

20

+

0

0 0.05 0 .

1 0.

1 5

Atrazine r a t e (mg/kg)

Fig . 4c Leeudoringstad

A soil

0.2 0.25

Figures 3C

&

4C Do s e-re s p o n s e to atrazin e in th e N e l s pruit a nd Leeudorin g s ta d A s oil s

1 00

% Dam age

80 y , 12 .07' 56 .

44 log(x • 100)

,

,

, 0.981

+

+

60

4 0

20

0

0 0.05 0.

1 0.15

Atraz in e rate (mglkg)

Fig

. 5c

Leeudoringstad B soil

0.2 0.25

252

96 Oamage

1 00 r--~ -------------------------------------. y , 3.9

4 , 66.72 log(x ' 1001

80

" , 0.973

+

+

60

+

4 0

20 o

0.05

_ _ _ _ _ _ _ _

_ _

0.

1 0.

1 5

A traz ine rate (mg/kg)

0 .

2

Fig.

6c

Ermelo A soil

0.25

Figures SC &

6C Dose-r e sponse to atrazine in the Leeudor in gstad Band Ermelo A soils

100

% Damage

y ,

0 .

978 t

64.97 lo g!x • 100 )

80

2 r

, 0.986

+

60

+

-b

+

4 0

20

0

0 0.05 0.1 0.

1 5

Atraz ine rate

(mg/kg)

Fig. 7e

Ny l stroom soil

0.2 0.25

253

100

96 Damage

y , -1.89 t

70 .

21 log(x • 100)

80 r

2

, 0.971 +

60

4 0

+

+

20

0

0 0 .

05

Fig.

8e

Bethal soil

0 .

1 0.15

Atrazine rate

(mglkg)

0.2 0.25

Figures 7C & 8C Dose response to atrazine in the Nylstroom and Bethal soils

100

% Damage

y

~

12.02 • 59.05 log(x • 100)

80 r

,

, 0.98

+

+

60

40

+

10

0

0

0.05 0 .

1 0.15

AtrllZ ine rate (mg/kg)

Fig . 9c Bothaville soil

0.1 0.25

254

100

96 Damage

80 y , -6.18 • 73 .

03 log(x ' 100)

, r ~

0.96

+

+

60

+

+ +

4 0

+

20

0

0

+

+

0.05 0.1 0 .

15

Atraz ine rate (mg/kg)

Fig . lOc Pretoria Al soil

0 .

2 0.25

Figures 9C

&

IOC

Dose-response to atrazine in the Bothaville and Pretoria Al soils

100

% Oam1!ge

y , -5.83 • 72.95 log(x • 1 00)

80 r

2

, 0.98

+

+

60

+

40

20

0 a

0.05 0.1 0 .

15

Alrazme rate (mg/ kg)

Fig. llc

Pretoria

A2 soil

0.2 0.25

255

100

96 Damage

y , -4.39

+

71.67 log(x • 100)

80

2 r

, 0.98

+

60

+

+

40

+

+

20 a

0 0.05 0.1 0.15

Atrazine rate

(mg/kg)

Fig.

12c

Pretoria

A3 soil

0.2 0 .

25

Figures lIC

&

12C

Dose-response to atraz in e in the Pretoria A2 and Pretoria A3 soils

100

%

Damage

y , ·4.39 t

7 1 .6J log(x I 1 00)

80

2 r , 0.98

+

60

+

40

T

+

+

+

2 0

0

0 0.05 0.

1 0.

1 5

Atraz ine rate

(mglkg)

Fig.

13c

Pretoria

A4 soil

0.2 0.25

256

100

% Damage

80 y , ·9.46 • 74.66 log(x • 100) r

,

, 0.96

60

+

4 0

20

0

+

-20

0 0.05 0.1 0.15

Atrazine rate

(mg/kg)

Fig.

14c

Pretoria

A5 soil

0.2 0.25

Figures 13C &

14C Dose-response to atrazine in the Pretoria A4 and AS soils

100

%

Damage

y ~ ~ 1 3.

11 t

69.55 log(x • 100)

80 r

1

, 0.95

+

60

40

+

+

20

0

+

+

-20

0 0 .

05 0.1 0.

1 5

Alraz ine rate

(mglkg)

Fig. 15c Warmbad

A soil

+

0.2 0.25

257

100

% Damelge

y ~ ~37.59 t

78.2

1 10g(x • 100)

80 + r

2

, 0.90

60

4 0

20

0

+ +

+

+

2 0

0 0.1 0.2 0 .

3

Atrazine rate

(mg/kg)

Fig.

16c

Warmbad

B soil

+

0.4 0.5

Figures 15C &

16C Dose respon s e to atra z ine in th e Wannbad A and Warmbad B s oils

100

% Damage

y ,

-37.29.

B2.2o log(x • 100)

80 r

,

, 0.95

+

60

+

40

20

0

-20

0 0.1 0.2 0.3

Atrazine rate (mgt kg)

Fig. l7c Utrecht soil

+

0.4

0.5

258

100

% Damage

80 y ,

-37.37 •

14.28 log(x • 100) r

,

, 0.91

+

60

40

+

+

20

0

+

+

20

0 0.1 0.2

O .

l

Atraz ine rate (mg/kg]

Fig. l8c Pretoria

B soil

0.4

0.5

Figures 17C &

18C Dose-response to atrazine in the Utrecht and Pretoria B so ils

% Damage

120,---~-------------------------------------, y , -4.83 • 65.77 l o g ('

*

10 0)

100 r

2

, 0.93

+

80

+

60

+

40

+

20

0

0 0.

1 0.2 0.3

Atraz in e r ate (mg/kg)

Fig. 19c Roodeplaat

soil

0.4

0.5

259

~

______ ____________________ - ,

120 ,y ,

-21.34 t

74.84 log(x • 1 00)

100

" , 0.86

+

80

60

40

20 o~+---------------------------------------~

_20L--------L------~--------L--------L----

__ o

0 .

1 0.2 0 .

3

0.4 0.5

Atrazine rate (mglkgj

Fig.

20c

Potgietersrus

soi l

Fig ur es 19C &

20C Do se -re spo n se to atrazine in the Rood ep laat and Potgietersrus soi l s

100

96 Oamoge

y ,

~3 .

15 t

73.60 log(x • 10 0)

80 r

2

, 0.9

1

60

+

~O

20

+

+

0

20

0 0 .

05

0 .

1 0.

1 5 0.2 0 .

25

Atraz ine rale ( m glkg )

Fig. 21c Morgenzon soil

+

0.3 0.35

260

100

% Damage

y , -36 .

95 t

79.99 log(x • 1 00)

80 r

2

, 0 .

95

60

+

4 0

+

20

0

+

+

+

- 20

0 0.05 0.1 O .

lS 0.2 0 .

1S

A l razine r ale (mg/kg)

Fig . 22c Carletonville soil

+

0.3 0.35

Figures 2IC

&

22C Dose

re s pon se to atrazine in the Morgenzon and Carletonville soils

96 Damage

60r---~-------------------------------------' yo -29.26 • 55.48 log (x • 1 00)

+

50

r2 =

0.89

4 0

30

+

20

+

1 0

+ +

0

-10

0 0.05 0.1 0.

1 5 0.2 0.25

Atrazine rate (mg/kg)

Fig.

23c

Vryheid soil

0.3 0.35

261

80

%

DClmeLge

60 y , 40.40,67.

23 log(x ' 10 0]

, r o

0.90

4 0

+

+

20

+

0

+

+

-20

0 0.05 0.1 0.15 0 .

2 0.15

Atrazine rate (mg/kg)

Fig.

24c

Errnelo

B

soil

+

0 .

3 0.35

Figures 23C & 24C

Dose-response to atrazine in the Vryheid and Ermelo B soils

%

80 r

__________________________________ - , y ,

-16.17 , 58.57 log!x • 100)

60

r2 :

0.87

40

20

+

0~~~-----------------------------------4

_20L____

_ _ _ _ o

0.05 0.

1 0.15 0.2 0.25

Atraz ine rate (mglkg]

Fig.

25c

Redhill soil

0.3 0.35

Figure 25C Dose-response to atrazine in the Redhill soil

262

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