What’s Happening What’s Happening in Weed Control in Weed Control

20012001

Dr. Eric P. Prostko

Extension Weed Specialist

Tifton

Certified Crop Advisors Meeting, Dec 15, 2000, Tifton GACertified Crop Advisors Meeting, Dec 15, 2000, Tifton GA

Topic for DiscussionTopic for Discussion

2000 Problems2000 Problems peanutspeanuts cottoncotton corncorn soybeans soybeans

How dry was it???How dry was it???May Precipitation in GeorgiaMay Precipitation in Georgia

0.01 0.03 0.4

4.023.36 3.4 3.66

0.310

1

2

3

4

5

Attapulgus Plains Tifton Statesboro

Location

Rai

nfal

l (in

)

2000 Average

85-90% of GA peanuts were planted in May85-90% of GA peanuts were planted in May

Drift Problems in 2000Drift Problems in 2000

Staple Plus on Sorghum

Roundup on Peanuts

Top 10 Tips For Reducing Top 10 Tips For Reducing Pesticide Drift ProblemsPesticide Drift Problems

nozzle selectionnozzle selection reduce pressurereduce pressure lower boom heightlower boom height increase nozzle sizeincrease nozzle size avoid spraying avoid spraying

when winds exceed when winds exceed 10 MPH10 MPH

lookout for lookout for inversionsinversions

use additivesuse additives calibrate sprayercalibrate sprayer keep recordskeep records use common use common

sensesense

““The Year of the Pigweed”The Year of the Pigweed”

dry weatherdry weather incorporationincorporation big weedsbig weeds Palmer amaranthPalmer amaranth resistance??resistance??

Palmer Amaranth Control with Blazer Palmer Amaranth Control with Blazer Applied at Different TimingsApplied at Different Timings

99

5748

0

25

50

75

100

3-5" 7-9" 11-13"

Timing

Con

trol

(%

)

Mayo et al. 1995 Mayo et al. 1995 (KS)(KS)

Pigweed Control with Blazer Pigweed Control with Blazer and Classic - 28 DATand Classic - 28 DAT

64 69

9197

0

25

50

75

100

Blazer Classic

Herbicide

Con

trol

(%

)

Palmer Smooth

Gossett and Toler, 1999Gossett and Toler, 1999 (SC) Applied at V3-V4 stage

Pigweed IdentificationPigweed IdentificationWorld Wide WebWorld Wide Web

Iowa State UniversityIowa State University

* * http://www.weeds.iastate.edu/weed-id/ http://www.weeds.iastate.edu/weed-id/ waterhemp/default.htmwaterhemp/default.htm

Kansas State UniversityKansas State University* http://www.oznet.ksu.edu/library/crpsl2/s80.pdf* http://www.oznet.ksu.edu/library/crpsl2/s80.pdf

PEANUTSPEANUTS

11% of peanut market11% of peanut market in southeast - 2000in southeast - 2000

How would you rate the overall How would you rate the overall performance of Strongarm in your county?performance of Strongarm in your county?

8

4943

00

15

30

45

60

75

Poor Fair Good Excellent

%

2000 UGA County Agent Survey2000 UGA County Agent Survey

What were the weeds that most What were the weeds that most frequently escaped control of Strongarm?frequently escaped control of Strongarm?

7872

2217

0

20

40

60

80

100

sicklepod nutsedge beggarweed pigweed

%

2000 UGA County Agent Survey2000 UGA County Agent Survey

Strongarm - Does it work in GA?Strongarm - Does it work in GA?Attapulgus - 7 WAPAttapulgus - 7 WAP

Untreated Strongarm + Prowl (PPI)

Variety Tolerance to Strongarm (PRE) Variety Tolerance to Strongarm (PRE) Tifton, GA 2000Tifton, GA 2000

5838 5767

0

1500

3000

4500

6000

7500

Untreated Strongarm

Herbicide

lbs/

A

Weed-free testAveraged over 2 varieties (GA Green, C99R)LSD 0.05 = 561

StrongarmStrongarmHow Should It Be Used in GA?How Should It Be Used in GA?

use where starbur, use where starbur, eclipta, and copperleaf eclipta, and copperleaf are problems are problems

tank-mix with DNAtank-mix with DNA irrigate in if possibleirrigate in if possible variable on nutsedgevariable on nutsedge poor sicklepod controlpoor sicklepod control

Strongarm Label UpdateStrongarm Label Update20012001

““at cracking” applicationsat cracking” applications

Snapbean rotation = 9 monthsSnapbean rotation = 9 months

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 label in 2001 label in 2001 (I hope!!)(I hope!!)

Why do we need Valor??Why do we need Valor??

Florida beggarweedFlorida beggarweed rotation restrictionsrotation restrictions mode of actionmode of action reduced costs/A?reduced costs/A?

Although Valor has many strengths, Although Valor has many strengths, growers/dealers need to be made growers/dealers need to be made

aware of its weaknesses such as . . . .aware of its weaknesses such as . . . .

cockleburcocklebur nutsedgenutsedge sicklepodsicklepod increased crop injury with delayed increased crop injury with delayed

applicationsapplications

Other Peanut Weed Control IssuesOther Peanut Weed Control Issues

paraquat formulationsparaquat formulations

* Starfire (old)* Starfire (old)

* Gramoxone Max* Gramoxone Max

* Boa* Boa Ultra BlazerUltra Blazer

* * sodium salt vs. amine formulationsodium salt vs. amine formulation

* less peanut injury???* less peanut injury???

COTTONCOTTON

GMO Cotton Varieties in GAGMO Cotton Varieties in GA

1832 32

82

0

20

40

60

80

100

Bt HerbicideResistant

Stacked All

Type

% o

f A

cres

Source: NASS, June 2000

Top 12 Varieties in 2000 GA CropTop 12 Varieties in 2000 GA CropB/RR RR B ConvDP 458 BR (14.8 %)DP 655 BR (7.0 %)SG 125 BR (3.6 %)DP 451 BR (3.4 %)ST 4892 BR (2.0 %)

DP 5690 RR (11.1 %)DP 90 RR (9.1 %)DP 5415 RR (4.9 %)

NuCOTN 35B (6.5 %)NuCOTN 33B (4.2 %)

FM 989 (3.2 %)DP 90 (2.1 %)

(USDA Ag Marketing Survey, Sep 2000)

Roundup Ready ProgramsRoundup Ready Programs

Options (6) Preferred StandardPPI / PRE Dinitroaniline

OTT 1-2 LF

OTT 2-4 LF

glyphosate orglyphosate + Staple

PDIR 6-10 LF

LAYBY

diuron or prometryn +MSMA

Glyphosate formulationsGlyphosate formulations((labeled for OT uses on RR cottonlabeled for OT uses on RR cotton))

Acquire Glyphomax Roundup Ultra

Credit Glyphomax Plus Roundup UltraDry

DuPont Glyph. Glyphosate Orig. Roundup UltraMax

Gly-Flo Rattler

Glyfos Roundup D-PAK Touchdown IQ*

Glyfos X-TRA Roundup Original

* not Touchdown 5L* not Touchdown 5L

Glyphosate is a good herbicide but Glyphosate is a good herbicide but it does have some weaknesses it does have some weaknesses such assuch as ….. ….. morningglorymorningglory nutsedgenutsedge dayflowerdayflower hemp sesbaniahemp sesbania prickly sidaprickly sida Florida pusleyFlorida pusley

Say Bye Bye to Bladex Say Bye Bye to Bladex (cyanazine)(cyanazine)

no sales or no sales or distribution after distribution after 9/30/029/30/02

cannot be used cannot be used after 12/31/02after 12/31/02

Does anyone Does anyone have some??have some??

Cyanazine ReplacementsCyanazine Replacements

diuron diuron prometrynprometryn fluometuronfluometuron CobraCobra

GoalGoal HarvadeHarvade ValorValor glyphosateglyphosate

Cyanazine ReplacementsCyanazine ReplacementsIssuesIssues

Contact activity (CoA)Contact activity (CoA) Residual activity (R)Residual activity (R) Carryover potential (CaP)Carryover potential (CaP) Injury potential (I)Injury potential (I) Cost ($)Cost ($)

Cyanazine ReplacementsCyanazine ReplacementsStrengths / WeaknessesStrengths / Weaknesses

diuron -- CoA, R, I, $ / CaP?diuron -- CoA, R, I, $ / CaP? prometryn -- CoA, R, CaP, I, $prometryn -- CoA, R, CaP, I, $ fluometuron -- R, I, $ / CoA, CaP?fluometuron -- R, I, $ / CoA, CaP? Cobra -- CoA, CaP, I / R, $Cobra -- CoA, CaP, I / R, $ Goal -- CoA, CaP, I / R, $Goal -- CoA, CaP, I / R, $ Harvade -- CoA, CaP, $ (IPOZZ) / RHarvade -- CoA, CaP, $ (IPOZZ) / R Valor -- CoA, R, CaP / I, $? experimentalValor -- CoA, R, CaP / I, $? experimental Glyphosate -- CoA, CaP, $ / R only RRGlyphosate -- CoA, CaP, $ / R only RR

Conventional ProgramsConventional ProgramsOptions (5) Preferred StandardPPI dinitroaniline

PRE fluometuron + Staple

Early POST MSMA orfluometuron + MSMA orStaple + MSMA

PDIR 6-10 in

LAYBY

diuron or prometryn +MSMA

CORNCORN

Weed Control in CornWeed Control in Corn

numerous optionsnumerous options tough to beat tough to beat

atrazine + cultivation atrazine + cultivation ($$$)($$$)

Prowl and/or Accent Prowl and/or Accent for PANTEfor PANTE

need something for need something for late-season MGlate-season MG

Weed Control in CornWeed Control in CornNew StuffNew Stuff

herbicide resistant hybridsherbicide resistant hybrids

* cost/A* cost/A

* hybrid performance* hybrid performance

* 6% of U.S. crop* 6% of U.S. crop

* GMO Issue* GMO Issue new labelsnew labels

Herbicide Resistant Corn Hybrid Herbicide Resistant Corn Hybrid TechnologiesTechnologies

Cost/ACost/A

Hybrid Seed Herbicide Total

RR $6.00 $6-8.00 $12-14.00

LL $0.00 $13-19.00 $13-19.00

Clearfield $0.00 $12.61 $12.61

Herbicide Resistant Corn Herbicide Resistant Corn Hybrids in GA - 2000Hybrids in GA - 2000

hybrids that performed equal to or hybrids that performed equal to or better than the test averages better than the test averages included the following:included the following:

* Pioneer 32K63LL (Liberty)* Pioneer 32K63LL (Liberty)

* Garst 8222 IT (Clearfield)* Garst 8222 IT (Clearfield)

* Dekalb 626RR (Roundup)* Dekalb 626RR (Roundup)

Weed Control in CornWeed Control in CornNew (er) LabelsNew (er) Labels

Accent Gold Accent Gold Action Action AxiomAxiom Axiom ATAxiom AT AimAim BalanceBalance

Celebrity PlusCelebrity Plus DistinctDistinct Degree ExtraDegree Extra EpicEpic NorthstarNorthstar SpiritSpirit

SOYBEANSSOYBEANS

GA Soybean ProductionGA Soybean Production1989-20001989-2000

0

300

600

900

1200

Year

Acr

es H

arve

sted

(X

100

0)

Source: GASS

Weed Control in SoybeansWeed Control in SoybeansRoundup Ready Tank-MixesRoundup Ready Tank-Mixes

Classic @ 0.33 oz/A ($3.14)Classic @ 0.33 oz/A ($3.14) FirstRate @ 0.15 ozs/A ($3.11)FirstRate @ 0.15 ozs/A ($3.11) Resource @ 4 ozs/A ($4.30)Resource @ 4 ozs/A ($4.30) improved control of morningglory (5-10%)improved control of morningglory (5-10%) mixed results across southern USmixed results across southern US cheaper than split applications of cheaper than split applications of

Roundup but not as effectiveRoundup but not as effective

Newer Roundup PremixesNewer Roundup PremixesSoybeansSoybeans

BASFBASF ExtremeExtreme

** Roundup (2 lb/gal) + Pursuit (0.17 lb/gal)Roundup (2 lb/gal) + Pursuit (0.17 lb/gal)

BackdraftBackdraft

** Roundup (1.25 lb/gal) + Scepter (0.25 lb/gal)Roundup (1.25 lb/gal) + Scepter (0.25 lb/gal)

knockdown + residualknockdown + residual NIS + N required on labelNIS + N required on label

Roundup/Boron/DimilinRoundup/Boron/DimilinTank Mixes??Tank Mixes??

full-bloom to early full-bloom to early pod-fillpod-fill

R2-R3 stageR2-R3 stage Is this the best time Is this the best time

for Roundup?for Roundup? Crop injury?Crop injury? Need more dataNeed more data

Soybean Yield Response to Soybean Yield Response to Roundup/Boron/Dimilin Tank-MixesRoundup/Boron/Dimilin Tank-Mixes

Hartz 7550RRHartz 7550RR

0 10 20 30 40

Untreated

Roundup (R)

Dimilin (D)

Boron (B)

R+D

R+B

D+B

R+D+B

Tifton, GA 2000 P = 0.85CV = 23

Bu/A

Weed Control in SoybeansWeed Control in SoybeansOther New(er) StuffOther New(er) Stuff

ActionAction AxiomAxiom BoundaryBoundary DetailDetail DomainDomain

ExpertExpert Pendimax Pendimax RaptorRaptor ResourceResource

University ofGeorgia

ExtensionWeed Science

http://mars.cropsoil.uga.edu/weedsci/