The Influence of Classic on TSWV of Peanuts

E. P. Prostko, R. C. Kemerait, W. C. Johnson, III, B. J. Brecke, and S. N. Brown

University of Georgia

Tifton

Annual Losses To TSWV inGeorgia Peanuts, 1990-2001

Year

1990 1992 1994 1996 1998 2000 2002

% R

ed

uc

tio

n i

n C

rop

Va

lue

0

2

4

6

8

10

12

14

To

tal

los

se

s i

n $

Mil

lio

ns

0

10

20

30

40

50% Reduction in Crop ValueTotal Loss in Dollars

Peanut Tomato Spotted Wilt Team, 2001

1993 1995 1997 1999 2001

The University of GeorgiaTomato Spotted Wilt Risk Index

• variety

• planting date

• plant population• insecticide• row pattern• tillage• others yet to be

discovered

Classic Issues in Peanut

• 20-25% of GA acreage

• late-season beggarweed

• tolerance of new varieties

• influence on TSWV

Objective

• evaluate the influence of Classic applications on TSWV and yield of peanut.

Materials and Methods

• small plot techniques

• 5 locations (4-GA, 1-FL)

• GA Green, C-99R

• Classic applied 21 to 90 DAE

• TSWV ratings

• yield

Materials and MethodsPlanting Dates

Location 2000 2001

Attapulgus, GA -- April 25

Colquitt Co., GA -- May 25

Jay, FL -- May 16

Tifton, GA May 8 May 10

ResultsTSWV

TSWV As Influenced By Classic Applications - 2000

19

31

37 37

28

21

0

10

20

30

40

Untreated 31 DAE 46 DAE 63 DAE 80 DAE 91 DAE

Classic Timing

TSW

V (

%)

Averaged over 2 varieties (GA Green, C-99R)* LSD (0.05) = 7+LSD (0.10) = 6

*+*+ *+

Tifton, GA

TSWV As Influenced By Classic Applications - 2001

2116

21 22

39

2627

0

10

20

30

40

50

Classic Timing

TSW

V (

%)

Averaged over 2 varieties (GA Green, C-99R)* LSD (0.05) = 9+LSD (0.10) = 7 Tifton, GA

*+

*+

TSWV As Influenced By Classic Applications - 2001

21 23

34

1922

34

21

0

10

20

30

40

Classic Timing

TSW

V (

%)

C-99R*LSD (0.05) = NS+LSD (0.10) = 11 Attapulgus, GA

+ +

TSWV As Influenced By Classic Applications - 2001

13

7

1719

26

118

0

10

20

30

Classic Timing

TSW

V (

%)

GA Green* LSD (0.05) = 11+LSD (0.10) = 9 Colquitt County, GA

*+

+

TSWV as Influenced by Classic Applications (2000-2001)

-15

-10

-5

0

5

10

15

20

0 15 30 45 60 75 90 105

Classic Timing (DAE)

Cha

nge

in T

SWV

(%

)

4 trials conducted in GAAveraged over 2 varieties (GA Green and C-99R)

ResultsPeanut Yield

Peanut Yield As Influenced By Classic Applications - 2000

5619

44644833

51755508

5838

0

1500

3000

4500

6000

Untreated 31 DAE 46 DAE 63 DAE 80 DAE 91 DAE

Classic Timing

lbs/

A

Averaged over 2 varieties (GA Green, C-99R)*LSD (0.05) = 561+LSD (0.10) = 467

*+ *+ *+

Tifton, GA

Peanut Yield As Influenced By Classic Applications - 2001

3124 3079 3123 3268 3177 32933471

0

1000

2000

3000

4000

Classic Timing

lbs/

A

Averaged over 2 varieties (GA Green, C-99R)*LSD (0.05) = 354+LSD (0.10) = 296 Tifton, GA

*+ + +

Peanut Yield As Influenced By Classic Applications - 2001

53565004 5186 5146 5427

49205274

0

1500

3000

4500

6000

Classic Timing

lbs/

A

C-99R*LSD (0.05) = 491+LSD (0.10) = 411 Attapulgus, GA

4038

3631

3997

3079

3880

3517

4105

0

1000

2000

3000

4000

5000

Yie

ld (

lbs/

A)

Peanut Yield as Influenced by Classic Timing - 2001

Jay, FL

Averaged over 2 varieties (GA Green, C-99R)*LSD 0.05 = 554+LSD 0.10 = 463

* ++

Peanut Yield as Influenced by Classic Applications (2000-2001)

-1500

-1300

-1100

-900

-700

-500

-300

-100

100

300

0 15 30 45 60 75 90 105

Classic Timing (DAE)

Cha

nge

in Y

ield

(lb

s/A

)

3 trials conducted in GA/1 trial conducted in FLweed-free conditions

What about other herbicides?

TSWV As Influenced By PRE Herbicides - 2000

26

21

26

21

0

10

20

30

Untreated Strongarm Valor Spartan

Herbicide

TSW

V (

%)

Averaged over 2 varieties (GA Green, C-99R)* LSD (0.05) = 7+LSD (0.10) = 6 Tifton, GA

TSWV in Response to Valor Timings

34 3320

45 46

6978

0

20

40

60

80

100

Valor Timing

TSW

V (

%)

Tifton, GASeptember 13, 2001

GA GreenPlanted: May 8

bc bc

c

b b

aa

TSWV As Influenced By Other Herbicide Applications - 2001

27

8

1621

2

23

1714

2924

7

21

0

10

20

30

40

Attapulgus Ponder Colquitt

TSW

V (

%)

Untreated Max + Bas (AE) fb Blazer (30 DAE)Max + Bas (AE) fb Cadre (30 DAE) Strongarm (60 DAE)

(LSD 0.05 - NS)(LSD 0.10 = 11)

(LSD 0.05 = 9)(LSD 0.10 = 7)

(LSD 0.05 = 11)(LSD 0.10 = 9)

TSWV As Influenced By Ultra Blazer Applications - 2001

17

26

19

28

1721

7

21

0

10

20

30

40

Blazer Timing

TSW

V (

%)

Averaged over 2 varieties (GA Green, C99R)* LSD (0.05) = 12+LSD (0.10) = 10 Tifton, GA

*+

Summary

• Classic can increase TSWV but not always.

• Classic/TSWV interaction can reduce yields but not always.

• Earlier applications of Classic??

• Other herbicides have not influenced TSWV.

ACKNOWLEDGMENT

This research was partially supported through a grant provided

by the Georgia Agricultural Commodity Commission for Peanuts.

University ofGeorgia

ExtensionWeed Science

(gaweed.com)