Weed Control Programs in Peanut with Reflex, Sharpen, and Spartan

Eric P. Prostko and Timothy L. GreyProfessor and Associate ProfessorDepartment of Crop & Soil Sciences

APRES 2010

Peanut Production

• Very important to southern region

• Minor crop to rest of country– 1,201,000 planted

acres in 2010

• Limited R&D for weed control

Potential New Peanut Herbicides?

Spartan (Sulfentrazone) in Peanut

• F-6285

• Crop injury and cotton rotations were the big issues

• Had a label in 2004 then????

Objective

• To evaluate the potential use of Spartan, Reflex, and Sharpen for weed control in peanut.

Materials and Methods Locations

Tifton Plains

Planting Date

May 28, 2009

May 12, 2009

Variety GA-06G GA-06G

PRE May 29 May 12

POST June 26

(29 DAP)

June 11

(30 DAP)

pH 6.0 6.1

OM (%) 1.53 1

Sand (%) 96 71

Silt (%) 0 13

Clay (%) 4 16

Materials and MethodsTreatments

• All programs included– Prowl H2O 3.8SC @ 2.1 pt/A (PRE)

– Cadre 2AS @ 4 oz/A + Agrioil @ 1% v/v (POST)

• Strongarm 84WG (SG)– 0.45 oz/A

• Valor 51WG (V)– 3 oz/A

• SG + V– 0.23 oz/A + 1.5 oz/A (1/2X rates)

• Spartan 4F (SP)– 4, 5, 6, 8 oz/A

• Reflex 2SL (R)– 12 and 16 oz/A

• Sharpen 2.85SC (SH)– 1 and 2 oz/A

Stages of growthPOST Timing

Tifton Plains

Peanut 4” tall

R1-R2

6” tall

Palmer

Amaranth

3-12” 2-8”

Annual

MG

3-6” --

Florida

Beggarweed

-- 1”

Results

Peanut Stunting (%) –TiftonJune 23 (25 DAT)

LSD 0.10 = 6

Peanut Stunting (%) –TiftonJuly 23 (55 DAT)

LSD 0.10 = 7

Peanut Leaf Burn (%) – PlainsJune 11 (27 DAT)

LSD 0.10 = 4

Spartan 4F @ 8 oz/A InjuryJune 23 (25 DAT)

Tifton

Sharpen 2.85SC @ 2 oz/A InjuryJune 23 (25 DAT)

Tifton

Palmer Amaranth Control (%) –TiftonJune 23 (25 DAT)

LSD 0.10 = 2

Palmer Amaranth Control (%) – PlainsJune 11 (27 DAT)

LSD 0.10 = 6

Annual MG Control (%) –TiftonJune 23 (25 DAT)

LSD 0.10 = 5

Spartan 4F @ 4 oz/AJune 23 (25 DAT)

Strongarm Based Program

NTCProwl H2O @ 34 oz/A – PRE

Strongarm 84WG @ 0.45 oz/A – PRECadre 2AS @ 4 oz/A – POST (29 DAP)

Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Valor Based Program

NTCProwl H2O @ 34 oz/A – PREValor 51WG @ 3 oz/A – PRE

Cadre 2AS @ 4 oz/A – POST (29 DAP)Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Strongarm/Valor Based Program

NTC Prowl H2O @ 34 oz/A – PREStrongarm 84WG @ 0.23 oz/A - PRE

Valor 51WG @ 1.5 oz/A – PRECadre 2AS @ 4 oz/A – POST (29 DAP)

Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Spartan Based Program

NTC Prowl H2O @ 34 oz/A – PRESpartan 4F @ 5 oz/A – PRE

Cadre 2AS @ 4 oz/A – POST (29 DAP)Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Reflex Based Program

NTC Prowl H2O @ 34 oz/A – PREReflex 2SL @ 16 oz/A – PRE

Cadre 2AS @ 4 oz/A – POST (29 DAP)Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Sharpen Based Program - 1

NTC Prowl H2O @ 34 oz/A – PRESharpen 2.85SC @ 1 oz/A – PRE

Cadre 2AS @ 4 oz/A – POST (29 DAP)Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Sharpen Based Program - 2

NTC Prowl H2O @ 34 oz/A – PRESharpen 2.85SC @ 2 oz/A – PRE

Cadre 2AS @ 4 oz/A – POST (29 DAP)Agrioil @ 1% v/v – POST (29 DAP)

PE-14-09July 2356 DAP

Florida Beggarweed Control (%) – PlainsAugust 1 (80 DAT)

98 98 99

91

99 97 99

57

36

9298

0

20

40

60

80

100

SG V SG/V SP4 SP5 SP6 SP8 R12 R16 SH1 SH2

LSD 0.10 = 14

Plains – August 1

NTC Prowl H2O @ 34 oz/A – PREReflex 2SL @ 12 oz/A – PRE

Cadre 2AS @ 4 oz/A – POST (27 DAP)Agrioil @ 1% v/v – POST (27 DAP)

Peanut Yield (lbs/A) - Tifton

LSD 0.10 = 455CV = 7.32

Summary - I

• Peanut Injury (Tifton)– Spartan (8 oz/A), Reflex and Sharpen

caused the most peanut injury.

• Peanut Injury (Plains)– Spartan (6 or 8 oz/A) caused the most

peanut injury. No injury from Reflex or Sharpen at this location.

• Palmer amaranth control was ≥ 92% with all treatments.– All treatments also included Prowl

Summary - II• Spartan @ 4 and 5 ozs/A and Reflex provided less

residual control of annual morningglory.

• Reflex provided less residual control of Florida beggarweed.

• Peanut Yield (Tifton)– When compared to the highest yielding

treatments, applications of Spartan @ 8 oz/A, Reflex, and Sharpen resulted in lower yields.

• Peanut Yield (Plains)– No data collected due to excessive weather.

Conclusions• Reflex

– Will not be pursued by Syngenta– Rotation restriction for peanut changed to 14 days

• 10 months on current label

• Sharpen– Too much injury at 2 oz/A!– Reduced weed control at 1 oz or less?

• Spartan– Spartan Charge was labeled in 2010

• 3-3.75 oz/A (coarse soils, <1.5% OM)• 3.75 oz/A = Aim 2EC @ 0.65 oz/A + Spartan 4F @ 2.9 oz/A

– Length of residual control at reduced rates particularly FL beggarweed and tropic croton?

– Cotton rotation restriction – 12 months

Sharpen 2.85SC @ 2 oz/A - 2010

PE-17-10June 8 (26 DAT)

229-392-1034 (cell)eprostko@uga.eduwww.gaweed.com