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)