Whatwill2,4‐DandDicambaAgronomicCropsMeanfor

VegetableProducers?StephenWeller

HLAPurdueUniversity

CurrentSituation

•  DowAgroSciencesandMonsantoaredevelopingagronomiccropswithresistanceto2,4‐Danddicamba.

•  Thistechnologyismovingforward•  Thistalkistoprovidebackgroundon:

–  thelogicforthistechnology–  informationaboutthetechnologyand– concernsweasvegetablegrowersshouldbeawareofasthismovesforward.

BackgroundonHerbicideResistantCrops

•  RoundupReady(RUR)AgronomicCrops– Revolutionizedweedmanagement

–  Increasedno‐tillpractices– Glyphosateappliedpostemergentduringcropseasonprovidedexcellentbroad‐spectrumweedcontrol

– RURCrops–soybean,corn,cotton,sugarbeet,canola

RURWeedManagement

•  Technologyhasnotbeenperfect•  Highselectionpressureonweeds•  Multipleapplicationswithinyears

•  Resistantweedsevolved– 21weedsworldwideareresistant– 3majorweedsinINconfirmed

• Marestail,giantragweed,waterhemp

– Othersuspected

Waterhemp  In the last 15 years, it has emerged as one of the most

problematic weeds to control in soybeans and corn  Documented resistance to triazines, ALS inhibitors, and PPO’s (not as widespread as ALS resistance at the current time)

 Best options for postemergence control in soybean besides PPO’s

Glyphosate Glufosinate (Liberty) Hand removal?

Triple-Stack Corn -  Yield Gard CB -  Yield Gard RW -  Roundup Ready

Triple-Stack Corn -  Herculex I -  Herculex RW -  Liberty Link

Triple-Stack Waterhemp -  ALS resistant -  PPO resistant -  Glyphosate resistant

Sensitive Noble County 0.75 lb ae/A – 21 DAT

GiantRagweedInIndiana

Sensitive Noble County 3.0 lb ae/A – 21 DAT

GiantRagweedInIndiana

WeatherMax 88 oz at 1 inch

WeatherMax 88 oz at 4 inch

WeatherMax 88 oz at 12 inch

PalmerAmaranthinCottoninGA,wedon’thaveit,YET!

WhatdoesWeedResistancetoRoundupMean?

•  Roundupreadytechnologyimperiled•  Requiresuseofadditionalherbicidetoolsandculturalpractices

•  Mustinvestigatenewcontrolmethodsanduseintegratedweedmanagementrelyinglessonthesoleuseofglyphosate

•  Herbicidecompaniesinvestigatingnewmethodsofweedcontrol

FutureWeedManagementTechnology

•  NewHerbicidemechanisms‐limited•  GeneticEngineeringtoobtaincropplantsresistanttootherherbicides

•  DowAgroSciences‐– EnlistWeedControlSystemwith2,4‐Dtoleranceincorn,soybeanandcotton

•  Monsanto – RoundupReadyPluswithdicambatoleranceincorn,soybeanandcotton

WhyHerbicideTolerantCrops?

•  ProvideanadditionaltoolintheRURsystem•  Aherbicidemanagementpackagethatwouldprovideawidespectrumofcontrolwithoutdamagingthecrop

•  Useofmultiplemechanismsofactionmixturesshouldsloworpreventfurtherevolutionofherbicideresistantweeds

•  MaintainsustainabilityofRURsystem

ConcernsRegardingthisTechnology

1.Howwillthisinfluenceweedmanagementinagronomiccrops?

2.Howwillwidespreaduseof2,4‐Danddicambaaffectnon‐targetcropsiftheseherbicidesmoveawayfromthetreatedfieldbydriftand/orvolatility?•  Ourconcernasvegetablegrowersisquestion2

PresentKnowledge

•  2,4‐Danddicambaprovidecontrolofmanybroadleafweedsthathavedevelopedresistancetoglyphosate

•  Thepossibilityofinjurytonon‐targetplantsfromdriftand/orvolatilityarewelldocumented

•  Driftofanyherbicidecancauseproblemsbutisespeciallyproblematicfortheseherbicidesasvegetablesarequitesensitivetoverylowdoses

•  Volatilityhasbeenaproblemwithcertain2,4‐Danddicambaformulations(2,4‐Desters,Banvel)

•  Mustensurethatthistechnologyisthoroughlytestedpriortoanyrelease

PresentStatusofEnlistTechnology

•  EnlistSystem– Genesdiscoveredthatmetabolize2,4‐Dandtheycanbetransformedintotargetcrops

– Abetterformulationof2,4‐Dwasnecessary•  Lessvolatile,lesssusceptibletodrift

–  Colex‐Dtechnologydeveloped•  2,4‐Dcholineisaquartnaryammoniumsalt,notanamineoranester

•  Ultralowvolatility•  Minimizedpotentialfordrift•  Lowodor•  Betterhandlingcharacteristics

2,4‐DMetabolismGene

PresentStatusofEnlistTechnology

•  Corn,soybeanandcottonindevelopment•  Allcropswillcontainglyphosateresistance•  Soybeanandcottonandsomecornwillcontainglufosinateresistance

•  Cornwillhaveresistanceto‘Fop’herbicides•  Offeranexpandedwindowofapplicationbothburndownandlaterinseason

•  Targetreleasedates–2013forcorn,2014forsoybean,2015‐16forcotton

PresentStatusofRoundupReadyPlusCrops

•  RoundupReadyPlus– Genesfordiscoveredthatmetabolizedicambaandcanbetransformedintotargetcrops

– Abetterformofdicambawasnecessary•  Lessvolatile,lesssusceptibletodrift

– dicambaformulationtechnology•  Ultralowvolatility• Minimizedpotentialfordrift

•  Betterhandlingcharacteristics

PresentStatusofRoundupReadyPlusCrops

•  Soybean,cornandcottonbeingdeveloped•  ResistancetoRoundup,dicambaandincottonglufosinate

•  Thistechnologywillprovidebetterweedcontrol,lesscropinjuryandgreaterflexibilityintimingofapplications

•  Releasedatein2015•  BASFandMonsantoworkingtogetheronherbicideandoff‐sitemovementissues

NewHerbicideResistantCropTechnologies

•  Willrequiretheuseofpreemergentherbicides

•  Researchbeingconductedon:– Appropriateapplicationtechnology

• Nozzles•  Effectofoff‐sitemovementbydriftandpotentialforvolatility

•  Environmentalconditioneffects

•  Susceptibilityofnon‐targetplants

WhatdoesthisTechnologymeanforVegetableGrowers?

•  Mustbeawareofthistechnology•  Willrequirebettercommunicationbetweenneighbors

•  Willthereberegulationsontheuseofthistechnology

•  Ifoff‐sitemovementoccurs,whatshouldbedone?

•  Whataboutdamage?

www.driftwatch.org

RegistryofPesticide‐sensitiveAreasdriftwatch(TM)isatooltohelpprotectpesticide‐sensitivecropsandhabitatsfromthedriftthatsometimesoccursduringsprayoperations

www.driftwatch.org

DriftWatchisaPurduebasedProgram

•  Thisprogramprovidesabaseofinformationtoallfarmersaboutthepresenceofsensitivecrops

•  Becomeawareofthissiteandhowtobeinvolvedtominimizeproblems

•  Mapsofsensitivecrops

•  Warningsofwhencropswillbeplantedorexist

WhatistheHLADepartmentdoing?

•  Developingdiagnostictoolsandinformationaboutvegetablecropsresponsetodrift

•  Whatarethesymptoms?

•  Whenorifcropsrecover?

•  Howmuchlossmightoccur?

•  Educationforapplicatorsonhowbesttousethenewtechnology

WhatistheHLADepartmentdoing?

•  Determinationofcropresponse•  Determinationofnozzlesusedinapplicationandhowfarparticlesmove

•  Environmentalconditionsthatresultinvolatilitypotential

•  SCRIgrantinvolvement

•  Companycooperation

WhatResultshavebeenGenerated?

•  Effectsoflow‐dose2,4‐DanddicambaandcombinationswithRoundupto:– Processingtomatoresponses– Freshmarketvegetablesresponse‐Tomatoes,peppers,muskmelon,watermelon

ExperimentalMethods–ProcessingTomatoes

•  TwoApplicationTimings–  Smallplants/Largeplants

•  Cultivars–  2007:611–  2008:611&311(IN),616&818(OH)

•  7Rates–  0,1/1000,1/300,1/100,1/30,1/10,&1/3XrateswhereX=0.5lbsae/A

fordicambaandX=0.6lbs/Aforglyphosate

•  Datacollected–  Cropinjury,yield(redandgreenfruit),and%flowerloss

•  Analysis–  Non‐linearloglogisticmodelinginR

•  PlotDesign–  1.5mx6mplots–  Tomatoestransplantedintoraisedbeds

CommonlyObservedSymptomswithDicamba

5 hours after treatment

3 days after treatment

7 days after treatment

14 days after treatment

28 days after treatment

Results

FlowerLoss– 5%

•  Timing1:1/233rd•  Timing2:1/373rd

– 25%•  Timing1:1/42nd

•  Timing2:1/88th

– 50%•  Timing1:1/15th•  Timing2:1/36th

MarketableFruitLoss–  1%

• Timing1:1/1120th• Timing2:1/622nd

–  5%•  Timing1:1/243rd

•  Timing2:1/224th

–  10%•  Timing1:1/124th•  Timing2:1/144th

(0.5 lbs ae/A = 1X)

Conclusions

•  Lowratesofdicambadriftresultedinsignificantyieldlossregardlessoftiming

•  Thesecondtimingatfloweringcausedhigheryieldlossthanthefirsttiming

•  Resultsweresimilaratbothlocationsandforallcultivarstested

•  Thereisariskofcausingtomatoyieldlossfromdicambadrift

CommonlyObservedSymptomscausedbyGlyphosate

3 days after treatment

7 days after treatment

21 days after treatment

28 days after treatment

Results

FlowerLoss– 5%

•  Timing1:1/20th•  Timing2:1/229th

– 25%•  Timing1:1/13th

•  Timing2:1/85th

– 50%•  Timing1:1/10th•  Timing2:1/47th

MarketableFruitLoss–  1%

• Timing1:1/58th• Timing2:1/337th

–  5%•  Timing1:1/30th

•  Timing2:1/164th

–  10%•  Timing1:1/22nd•  Timing2:1/120th

(0.6 lbs ae/A= 1X)

Conclusions

•  Glyphosatedriftatthetimeoffruitsetleadstogreaterfruitlossthanatthetimeoftransplanting

•  Glyphosatedriftdelayedfruitripening•  Bothcultivarstestedrespondedsimilarlytoglyphosatedrift

•  Tomatoesaresensitivetoevenlowratesofglyphosate

Gly1/300X Gly1/100X Gly1/30X

Dicamba1/300X Dicamba1/100X Dicamba1/30X

Gly1/300XDicamba1/300X

Gly1/100XDicamba1/100X

Gly1/30XDicamba1/30X

Untreated

TomatoResponsetocombinationsof GlyphosateandDicambaDrift

Untreated 1/100X 1/100X 1/100+1/100 glyphosate dicambaGly+dicamba

TomatoResponsetocombinationsof GlyphosateandDicambaDrift

Untreated 1/30X 1/30X 1/30+1/30 glyphosate dicambaGly+dicamba

Glyphosate rate

Dicamba rate

Expected results1

Observed results2

Difference in results Joint activity

______ lbs ae/A______ _____________ % Control _____________

2 WAT

1/300 + 1/300 26 21 -5 Additive

1/100 + 1/100 61 74 13 Synergistic

1/30 + 1/30 95 94 -1 Additive

5 WAT +

1/300 + 1/300 40 32 -8 Additive

1/100 + 1/100 67 69 2 Additive

1/30 + 1/30 95 91 -4 Additive

Theeffectsofthreedifferentdriftratesofdicambaandglyphosateoncommercialprocessingtomatoes.

Conclusions

•  Driftfromcombinationsofglyphosateanddicambahaveanadditiveeffectoncausingtomatoinjury

•  1/30x+1/30Xresultedin>90%injury•  Driftfromeitherglyphosateordicambacausesseriousinjury

•  Driftfromacombinationofthe2herbicidescausesevengreaterinjury

MethodsandMaterials

•  2010and2011studiesperformedatMeigsHorticultureResearchFarminLafayette,IN.

•  Fourvegetablecropswereused:• “Mt.FreshPlus”tomato• “Aristotle”bellpepper• “HalesBestJumbo”cantaloupe• “MardiGras”watermelon

CantaloupeInjury,21DAT

Untreated 8gaeha‐1

8gaeha‐1+8gaeha‐1gly 4gaeha‐1 4gaeha‐1+4gaeha‐1gly

16gaeha‐1

2,4‐D

CantaloupeInjury,21DAT

Untreated 5.6gaeha‐1

5.6gaeha‐1+8gaeha‐1gly 2.8gaeha‐1 2.8gaeha‐1+4gaeha‐1gly

11.2gaeha‐1

Dicamba

TomatoInjury,21DAT

Untreated 8gaeha‐1

8gaeha‐1+8gaeha‐1gly4gaeha‐1 4gaeha‐1+4gaeha‐1gly

16gaeha‐1

2,4‐D

TomatoInjury,21DAT

Untreated 5.6gaeha‐1

5.6gaeha‐1+8gaeha‐1gly 2.8gaeha‐1 2.8gaeha‐1+4gaeha‐1gly

11.2gaeha‐1

Dicamba

ConclusionsTotalHarvest

•  Cantaloupe•  Initialdelayinfruitmaturity•  2,4‐Dtreatedplantsyieldedlessthanuntreated.•  Therewasnototalyielddifferencebetweenuntreatedanddicamba‐treatedplants.

•  Tomato• Delayinfruitmaturitybutoverallnodifferencebetweenuntreatedandtreatedplantsforeither2,4‐Dordicamba.

SCRIResearch

•  Willdetermineeffectsof:– Wind–  Formulation– NozzletypeOnherbicidemovementFurther,wewill:– Quantifyamountsofherbicidethatmove– Quantifyeffectoncropinjury,croprecovery,timetofruitmaturityandcropyield/quality

–  ConductedonmajorvegetablecropsgrownintheMidwestU.S.