Peanut Weed Control Update 2002 UGA Extension Agent Training Eric P. Prostko Extension Weed Specialist Tifton.

Peanut Weed Control Update

2002 UGA Extension Agent

Training

Eric P. Prostko

Extension Weed Specialist

Tifton

Topics for Discussion

• Valor Problems

• Ultra Blazer Injury

• Classic Concerns

• “herbicides on the horizon”

• 2002 Research

Peanut Acres Treated with Valor and Injury by Region in 2001

0

5,000

10,000

15,000

20,000

25,000

30,000

Atlantic Southeast Oklahoma Texas

Acr

es

Acres Treated Acres Injured

Source: Valent USA Corp.Source: Valent USA Corp.

Valor Injury

Valor Performance

Valor No Valor

Irwin Co, 2001

Peanut Yield As Influenced By PRE Herbicides - 2000

5767 57695456

5838

0

1500

3000

4500

6000

Untreated Strongarm Valor Spartan

Herbicide

lbs/

A

Averaged over 2 varieties (GA Green, C99R) * LSD (0.05) = 561 Lang Farm

Valor Timing Tests - 2002

• 5 locations

• small plot techniques

• Valor (3 oz/A) applied 0 to 10 DAP

• weed-free conditions

• crop injury, yield, maturity

Peanut Yield in Response to Valor Timings

4673

39604221

36803394

2496

1567

0

1000

2000

3000

4000

5000

Untrea

ted

0 DAP

1 DAP

3 DAP

5 DAP

7 DAP

10 D

AP

Valor Timing

lbs/

A

GA GreenTifton, GA 2001

aabc ab bc

c

d

e

Peanut Yield in Response to Valor Timings

4526 4552 44084580

41884459

0

1000

2000

3000

4000

5000

0 DAP 2 DAP 4 DAP 6 DAP 8 DAP 10 DAP

Valor Timing

lbs/

A

C-99RAttapulgus, GA 2001 P = 0.66

Peanut Yield in Response to Valor Timings

3704 38034027 3881 3939

42973789

0

1000

2000

3000

4000

5000

Untrea

ted

0 DAP

1 DAP

3 DAP

5 DAP

7 DAP

10 D

AP

Valor Timing

lbs/

A

NC 12CLewiston, NC 2001 P = 0.56

Peanut Yield in Response to Valor Timings

68756301

6564 6723 67316476

0

1000

2000

3000

4000

5000

6000

7000

Untreated 0 DAP 2 DAP 4 DAP 6 DAP 8 DAP

Valor Timing

lbs/

A

GA GreenCitra, FL 2001 P = 0.31

Peanut Yield in Response to Valor Timings

3394

41204483

4109 39643616

3234

0

1000

2000

3000

4000

5000

Untrea

ted

0 DAP

1 DAP

3 DAP

5 DAP

7 DAP

10 D

AP

Valor Timing

lbs/

A

GA GreenYoakum, TX 2001 P = 0.48

Valor in Peanuts - 2002Suggestions

• calibration

• pre-slurry

• plant 1.5” deep

• apply at planting

• do not irrigate when cracking

• hull scrape

• limited acreage

Ultra Blazer in Peanuts

• new formulation

• G-E control of croton, ragweed, mg, pigweed, etc

• Concerns

* crop injury

* yield loss???

Peanut Yields As Influenced By Ultra Blazer Applications - 2001

(1.5 pts/A + COC 1% v/v)

5265 5649 53304883 4758

54154533

5491

0

1300

2600

3900

5200

6500

Untreat

ed

30 D

AP

45 D

AP

60 D

AP

74 D

AP

88 D

AP

120 D

AP

30 +

88 D

AP

Timing

lbs/

A

Averaged over 2 varieties (GA Green, C99R)*LSD (0.05) = 311+LSD (0.10) = 260 Ponder Farm

Peanut Yields As Influenced By Ultra Blazer Applications - 2001

(1.5 pts/A + COC 1% v/v)

52395704 5470 5631

48425241

5696

0

1300

2600

3900

5200

6500

Untreat

ed

30 D

AP

42 D

AP

55 D

AP

82 D

AP

90 D

AP

30 +

90 D

AP

Timing

lbs/

A

Averaged over 2 varieties (GA Green, C99R)*LSD (0.05) = NS+LSD (0.10) = 534 Plains, GA

4112

5139

4457 45294868

4136 3947

0

1000

2000

3000

4000

5000

6000

Untrea

ted

23 D

AP

36 D

AP

51 D

AP

65 D

AP

79 D

AP

99 D

AP

Timing

Yie

ld (

lbs/

A)

Peanut Yields as Influenced by Ultra Blazer Applications - 2001

(1 qt/A + Induce 0.25% v/v)

Averaged over 2 varieties (GA Green, C99R)P = 0.20 Jay, FL

Ultra Blazer in Peanuts

• small weeds

• before 65 DAP

• surfactant

• 0.5-1.5 pts/A

Classic Issues in Peanut

• 20-25% of acreage

• late-season beggarweed

• tolerance of new varieties

• influence on TSWV

Does Classic have an influence on TSWV in peanut?

• Studies conducted in 2000-2001 indicate…..

• Classic can increase TSWV but not always.

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

• Earlier applications??

TSWV as Influenced by Classic Applications (2000-2001)

-15

-10

-5

0

5

10

15

20

0 20 40 60 80 100

Classic Timing (DAE)

Cha

nge

in T

SWV

(%

)

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

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

-1500

-1300

-1100

-900

-700

-500

-300

-100

100

300

0 20 40 60 80 100

Classic Timing (DAE)

Cha

nge

in Y

ield

(lb

s/A

)

2 trials conducted in GA/1 trial conducted in FLAveraged over 2 varieties (GA Green and C-99R)weed-free conditions

“Herbicides on the Horizon”??

• Spartan (FMC)

* broadleaf/y. nutsedge

* crop injury concerns

* cotton rotations• Callisto (Syngenta)

* preemergence

* broadleaf weeds

* early development

2002 Research Focus

• tropic croton control (Cadre tank-mixes)

• dayflower/spiderwort control

• herbicide/fungicide tank-mixes

• reduced rates of Strongarm + Valor

• Classic/TSWV

• others???

University ofGeorgia

ExtensionWeed Science

(gaweed.com)