WEED CONTROLWEED CONTROL IN PEANUTSIN PEANUTS

20002000

Dr. Eric P. ProstkoExtension Weed Specialist

Department of Crop & Soil SciencesUniversity of Georgia

Tifton

Top 10 Most Troublesome Top 10 Most Troublesome Weeds in Georgia PeanutsWeeds in Georgia Peanuts Fla. Fla.

BeggarweedBeggarweed nutsedgenutsedge tropic crotontropic croton sicklepodsicklepod Texas Texas

panicumpanicum

bristly starburbristly starbur morninggloriesmorningglories wild poinsettiawild poinsettia citronmelon citronmelon pigweedspigweeds

Peanut Weed ControlPeanut Weed ControlMethodsMethods

culturalcultural

mechanicalmechanical

chemicalchemical

When do those weeds When do those weeds needneed

to be controlled?? to be controlled??

Weed Competition in Weed Competition in Peanuts - IPeanuts - I

Critical Periods (weeks)Critical Periods (weeks)

PlantMinimumWeed-free

MaximumInterference

horsenettle 2 6s. nightshade 4-12 <4cocklebur 12 2b. signalgrass 6 6f. panicum 2 2

Weed Competition in Weed Competition in Peanuts - IIPeanuts - II

Critical Periods (weeks)Critical Periods (weeks)

PlantMinimumWeed-free

MaximumInterference

w. poinsettia 10 2bristly starbur 6 2f. beggarweed 4 10sicklepod 4 10

Peanut Weed ControlPeanut Weed ControlHerbicide Selection Based Herbicide Selection Based

Upon...Upon...

weed problemsweed problems

rotational cropsrotational crops

cost/Acost/A

Peanut Weed ControlPeanut Weed ControlSoil-Applied HerbicidesSoil-Applied Herbicides

DualDual FrontierFrontier LassoLasso ProwlProwl

PursuitPursuit SonalanSonalan Vernam (?) Vernam (?) ZorialZorial

Prowl and Sonalan Label Prowl and Sonalan Label Changes for 2000Changes for 2000

can now be applied PREcan now be applied PRE after planting but before after planting but before

emergenceemergence must be irrigated within 48 be irrigated within 48

hourshours

** Prowl: 0.75” Prowl: 0.75”

** Sonalan: 0.5-1.0” Sonalan: 0.5-1.0”

Preplant Incorporated vs. Preplant Incorporated vs. PreemergencePreemergence

0

20

40

60

80

100

PANTE DIGSP DTTAE

Weed

Con

trol

(%

)

Sonalan-PPISonalan-PREProwl-PPIProwl-PRE

W.C. Johnson, III 1997-99

Herbicide IncorporationHerbicide Incorporation herbicide in upper 2”herbicide in upper 2” operating depth (4”)operating depth (4”) Roterra/power tillerRoterra/power tiller tandem disk - 2X tandem disk - 2X

** perpendicular, perpendicular, angleangle

field cultivator - 2Xfield cultivator - 2X

** angle onlyangle only irrigationirrigation

Do you need a soilDo you need a soil

applied herbicide???applied herbicide???

Peanut Yield Peanut Yield With/Without PPI Herbicides (PPI)With/Without PPI Herbicides (PPI)

967

1754 1842 1764

0

500

1000

1500

2000

None Dual II Frontier Sonalan

Herbicide

Yiel

d (l

bs/A

)

TAES, Yoakum, 1997 LSD 0.05 = 579

Peanut Weed ControlPeanut Weed ControlPostemergence HerbicidesPostemergence Herbicides

BasagranBasagran BlazerBlazer CadreCadre ClassicClassic Poast PlusPoast Plus

PursuitPursuit SelectSelect StarfireStarfire StormStorm ToughTough 2,4-DB2,4-DB

Why didn’t my Why didn’t my postemergence postemergence herbicide work??herbicide work??

Weed Control - Weed Control - PostemergencePostemergenceKeys to SuccessKeys to Success

calibration calibration

timing, timing, timing, timing,

timingtiming

additivesadditives

nozzle selectionnozzle selection

growing conditionsgrowing conditions

The influence of additives on The influence of additives on sicklepod control with Cadre - sicklepod control with Cadre -

68 DAT68 DAT

44

91 91

66

87

0

20

40

60

80

100

None Phase LI 700 Herbimax DyneAmic

Additive

Con

trol

(%

)

A. S. Culpepper, 1999A. S. Culpepper, 1999 LSD 0.05 = 5LSD 0.05 = 5

Nozzle SelectionNozzle Selection

Cadre Rotational ConcernsCadre Rotational Concerns

18 month cotton 18 month cotton rotationrotation

dry weather at time dry weather at time of application very of application very importantimportant

injury as low as 1.8 injury as low as 1.8 ppbppb

crop recovery??crop recovery??

Florida Beggarweed Florida Beggarweed ControlControl

Zorial - PREZorial - PRE Starfire + Storm or Starfire + Storm or

Basagran - CRACKBasagran - CRACK Tough + 2,4-DB - Tough + 2,4-DB -

EPOST (3”)EPOST (3”) Cadre - EPOST (2”)Cadre - EPOST (2”) Classic - LPOST (10”)Classic - LPOST (10”) new productsnew products

Peanut Weed ControlPeanut Weed ControlStrip TillageStrip Tillage

knockdownknockdown

* * RoundupRoundup

* * GramoxoneGramoxone

** 2,4-D ?? 2,4-D ?? residualsresiduals postemergencepostemergence

rainfall/irrigationrainfall/irrigation

New Options For Weed New Options For Weed Management in PeanutsManagement in Peanuts

SpartanSpartan Strongarm Strongarm ValorValor

Spartan 75DF or 4L Spartan 75DF or 4L FMC FMC introduced in 1991introduced in 1991 sulfentrazonesulfentrazone triazolinone familytriazolinone family PPO oxidase inhibitorPPO oxidase inhibitor PPI or PREPPI or PRE 5.3 ozs/A (DF) or 8 ozs/A (4L) 5.3 ozs/A (DF) or 8 ozs/A (4L)

Strongarm 84WDGStrongarm 84WDG

Dow AgroSciences Dow AgroSciences introduced in 1995introduced in 1995 diclosulam diclosulam sulfonanilide familysulfonanilide family ALS/AHAS inhibitorALS/AHAS inhibitor PPI or PREPPI or PRE 0.45 oz/A 0.45 oz/A

Valor 50WDG Valor 50WDG Valent Valent introduced in 1989introduced in 1989 flumioxazinflumioxazin NN-phenylphthalimide derivative-phenylphthalimide derivative PPO oxidase inhibitorPPO oxidase inhibitor PREPRE 2-3 ozs/A 2-3 ozs/A

Crop Rotation Restrictions Crop Rotation Restrictions - I- I

(months)(months)Herbicide Cotton Corn Soybean Tobacco Wheat

Spartan 18 10 0 0 4

Strongarm 10 18 0 18 4

Valor 4 4 0 4 4

Cadre 18 9 9 9 4

Crop Rotation Restrictions Crop Rotation Restrictions - II- II

(months)(months)Herbicide watermelon onion sweet

cornsnapbeans

Spartan ? ? 18 ?

Strongarm 30 30 30 30

Valor 12(FB)

12(FB)

4 12(FB)

Cadre 26 26 18 9

Florida Beggarweed Florida Beggarweed ControlControl

8192

8573

0

25

50

75

100

Strongarm Valor Spartan Cadre

Herbicide

% C

ontr

ol

Yellow Nutsedge Yellow Nutsedge ControlControl

76

36

8693

0

25

50

75

100

Strongarm Valor Spartan Cadre

Herbicide

% C

ontr

ol

Tropic Croton ControlTropic Croton Control

7890

98

70

0

25

50

75

100

Strongarm Valor Spartan Cadre

Herbicide

% C

ontr

ol

Bristly Starbur Bristly Starbur ControlControl

92 94 93

78

0

25

50

75

100

Strongarm Valor Spartan Cadre

Herbicide

% C

ontr

ol

Wild Poinsettia Wild Poinsettia ControlControl

97 92 9790

0

25

50

75

100

Strongarm Valor Spartan Cadre

Herbicide

% C

ontr

ol

Hophornbeam Hophornbeam Copperleaf Copperleaf

Stand Reduction - 31 DAPStand Reduction - 31 DAP

9893

7261

0

25

50

75

100

Strongarm(PPI)

Strongarm(PRE)

Valor (PRE)

Cadre(POST)

% R

educ

tion

Erath County, TX 1999Erath County, TX 1999 Includes Sonalan at 2 pts/A - PPIIncludes Sonalan at 2 pts/A - PPI

SummarySummaryNew ProductsNew Products

crop safety concerns crop safety concerns new products will help new products will help

control many weeds in control many weeds in peanutspeanuts

rotational concernsrotational concerns When will they be When will they be

labeled??? labeled??? How much will they How much will they

cost??cost??

UniversityUniversityof Georgiaof Georgia

Weed ScienceWeed Science