weed management in texas cottoncotton.tamu.edu/weed management/cotton weed control 042016.pdf ·...

WeedManagementinTexasCotton

SCS-2016-16

WeedManagementinTexasCotton

JoshuaMcGinty,Ph.D-AssistantProfessorandExtensionAgronomist,CorpusChristi,TX

EmiKimura,Ph.D.-AssistantProfessorandExtensionAgronomist,Vernon,TXPaulBaumann,Ph.D.-ProfessorandStateExtensionWeedControlSpecialist,CollegeStation,TX

PeteDotray,Ph.D.-ProfessorandExtensionWeedControlSpecialist,Lubbock,TXGaylonMorgan,Ph.D.-ProfessorandExtensionCottonSpecialist,CollegeStation,TX

Contents

GENERALPRACTICES....................................................................................................................................2

HERBICIDERESISTANCE...............................................................................................................................2

Table1.Mechanismofactionofherbicideslabelledforuseincotton.......................................................4

CULTURALCONTROL...................................................................................................................................5

PREPLANTBURNDOWN...............................................................................................................................7

WEEDMANAGEMENTATPLANTING...........................................................................................................7

POSTEMERGENCEWEEDCONTROL.............................................................................................................7

POST-HARVESTWEEDMANAGEMENT........................................................................................................8

Table2.Preplantburndownherbicideoptions...........................................................................................9

Table3.Preplant-incorporatedherbicideoptions....................................................................................13

Table4.Preemergenceherbicideoptions.................................................................................................15

Table5.Postemergenceover-the-topherbicideoptions..........................................................................18

Table6.Post-directedorhoodedherbicideoptions.................................................................................22

Table7.Wickorwiperappliedherbicideoptions.....................................................................................26

PHOTOGRAPHSOFCOMMONWEEDS......................................................................................................27

2

GENERALPRACTICES

Akeycomponentinsuccessfulcottonproductionistheeffectivemanagementofweeds.Thecottonplantisnotparticularlycompetitivewithmanyweedspecies,especiallyearlyintheseason.Researchhasshownthatevenlightinfestationsofweedsduringthisperiodoftimecansignificantlyimpactcottonyields.Weedscanalsocreatedifficultiesduringharvestandnegativelyimpactlintqualityduetostainingandincreasedforeignmaterialinthelint.Thispublicationdescribeskeypointstoconsiderwhenmanagingweedsincottonaswellascurrentrecommendationsforcontrol.

HERBICIDERESISTANCE

Herbicideresistantweedsarenaturallyoccurringbiotypesofaspecieswiththeinheritedabilitytosurviveandreproducedespiteexposuretoaherbicidethatpreviouslywaseffectiveforcontrollingthespecies.Thetermbiotypedescribesplantswithinaweedspeciesthatmaylookexactlyalikebuthavebiologicaltraitsuncommontothepopulationasawhole.Thedevelopmentofresistanceisacceleratedwhenweedcontrolmeasuresrelyheavilyuponchemicalcontrolandwithoutincludingcultural,mechanical,andbiologicalweedcontrolmeasures.Therearecurrently246species(143dicotsand103monocots)ofherbicideresistantweedsglobally(Heep,2015).Ofwhich,herbicideresistantweedsidentifiedinTexasincludeperennialryegrass(ALSinhibitors),barnyardgrass(PSIIinhibitor),Palmeramaranth(PSIIinhibitorsandEPSPsynthaseinhibitors),kochia(ALSinhibitors),johnsongrass(ALSinhibitors),andtallorcommonwaterhemp(EPSPsynthaseinhibitors)(Heap,2015).Oftheseherbicideresistantweedcases,theglyphosateresistantAmaranthusspp.(Palmeramaranthandcommonwaterhemp)arethemosttroublesomeinTexascottonduetothewidespreadrelianceuponglyphosatealoneforweedmanagement.Theseweedsarecapableofproducinginexcessof500,000seedperfemaleplantandcanspreadrapidlythroughoutaregiononceestablished.Belowareafewkeypointstoconsiderformanagingtheseherbicideresistantweeds.

PreventionandManagementofResistantWeedsa. Diversifycropproductionpractices

Croprotationisoneofthemostsignificantcomponentsofeffectiveweedmanagementincotton.Inadditiontohelpingwithnematodeanddiseasemanagement,croprotationsallowtheuseofadditionalherbicidemechanismsofaction.

b. CultivationOnceamainstayofweedmanagementincotton,cultivationhasdeclinedsignificantlywiththecommercializationofglyphosateandglufosinatetolerantcottonvarieties.However,withtheriseofglyphosateresistantweedsincottonproduction,cultivationisonceagainaviableweedmanagementtoolinmanyoperations.

c. Usetherecommendedrate,timingofapplication,andsprayvolume.Whenapplyinganyherbicide,besuretousethefulllabeledrateofthatproductandapplyatthepropertime.Manypostemergenceherbicidesareonlyeffectivewhenappliedtoverysmallweeds.Ifappliedtoolateorattoolowanapplicationrate,weedescapescanbeexpected.Theefficacyofnon-systemicherbicides,suchasglufosinate(Liberty),ishighlydependentuponobtainingthoroughspraycoverageasisstatedontheproductlabel.Goodspraycoverageisachievedbyapplyingtherecommendedcarriervolumeandusingtheappropriatespraynozzle.

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d. AvoidusingasinglemechanismofactioninyourherbicideprogramHerbicidemechanismofactiondescribesthewaythataherbicidecontrolssusceptibleweedspecies.Currently,thereare12herbicidemechanismsofactionavailableforuseincotton(Table1).Itisimportanttotargetproblematicweedspecieswithatleasttwodifferentmechanismsofaction,andtochangeherbicideprogramsfromyeartoyear(Figure1).TheWeedScienceSocietyofAmerica(WSSA)hasdevisedanumberingsystemforclassifyingherbicidemechanismsofactionintogroups.Often,thesegroupnumberscanbefoundonproductlabels.AllherbiciderecommendationsinthispublicationwillincludetheWSSAgroupnumber(s)foreachherbicide.UseoftheWSSAnumberingsystemshouldbeasimplerapproachforunderstandingtheherbicidemechanismofaction.

Figure1.Exampleofthesustainabilityofutilizingmultipleherbicidesitesofactionandrotatingthesefromseasontoseason(adaptedandmodifiedfromwssa.net).

Season1:Group9

Season2:Group9

Season3:Group9

Season1:Group9and4

Season2:Group9and14

Season3:Group1and2

SustainableMinimizesresistantweed

evolution

NotSustainableAcceleratestheevolution

ofresistantweeds

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Table1.MechanismofactionofherbicideslabelledforuseincottonMechanismofAction WSSAGroup# Representativeproducts

ACCaseinhibitors 1 AssureII,FusiladeDX,PoastPlus,SelectMax

ALSinhibitors 2 Envoke,Express,FirstShot,Harmony,LeadOff,Staple

Microtubuleassemblyinhibitors 3 Prowl,TreflanSyntheticauxins 4 2,4-D,Clarity

PhotosystemIIinhibitors5 Caparol,7 Cotoran,Direx,Karmex,Linex

EPSPsynthaseinhibitors 9 Roundup(glyphosate)Glutaminesynthetaseinhibitors 10 Liberty

Carotenoidbiosynthesisinhibitors12 BrakeFX13 Command

PPGoxidaseinhibitors 14 Aim,Cobra,ET,Goal,Reflex,Resource,Sharpen,Valor

VLCFAinhibitors 15 DualMagnum,Warrant,Zidua,Outlook

Unknown 17 MSMAPhotosystemIinhibitors 22 GramoxoneSL

e. Keeprecordsofweedpopulationsandherbicideapplication

Goodrecordkeepinghelpstoplananeffectivepreventionprogramforherbicideresistantweeds.Italsohelpstoavoidusingthesameherbicidemechanismofactioneachyear.Ifaherbicideprogramfailedtocontrolaweedorweeds,thatprogramshouldbeavoidedinthefieldwherethefailure(s)wereobserved.Repeatedapplicationsofthesameherbicidewillonlyservetoincreaseherbicideresistantweeds.

f. ScoutherbicidefailuresfollowingsprayingWeedswhichsurviveaherbicideapplicationmaybetheresultofapplicationerrorsandarenotnecessarilyresistantweeds.Herbicidefailurecanbecausedbypoorspraycoverage,incorrecttimingofapplications,“washing-off”ofpostemergenceherbicidesbyrainfall,oradverseenvironmentalconditionssuchaspoorsoilmoisture,lowhumidity,orextremetemperatures.Whenweedcontrolfailuresoccur,checktoseeifspatialpatternsexistinthefield.Ifsurvivingweedsarepresentin“streaks”acrossthefield,thismaybetheresultofanapplicationerror.Ifthedistributionofsurvivingweedsisscatteredor“patchy”,thismayindicatethepresenceofaherbicideresistantbiotype.Ifresistantweedsaresuspected,itcanbeconfirmedbycollectingseedsofthesuspectedresistantweedsandhavingalegitimatescreeningtrialconductedonthemtodetermineresistance.Afew“redflags”ofherbicideresistantweedsare:(1)ifthesameherbicidehasbeenrepeatedlyappliedinthesamefield,(2)thesameweedspeciesarerepeatedlyfoundsurvivinginthesamelocationofthefield,and(3)ifdead(susceptible)plantscanbefoundatthesamelocationasthesurvivingweedsandthesedeadplantswereatthesamestageofgrowthatapplication.

Formanagementstrategiesforglyphosateresistantpigweeds,pleaserefertotheAgriLifeExtensionpublication,‘4-stepProgramforManagingGlyphosateResistantPigweedsinTexasCotton’.

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CULTURALCONTROLFieldSelection

Growthofcottonseedlingsisslowbecauseoftheperennialnatureofcotton,whichdevotesmuchofitsenergyintorootdevelopmentratherthanshootgrowth.Thefirst10weeksafterplantingisthecriticaltimeofweedmanagementuntilcottonseedlingsbecomecompetitiveagainstweeds(BuchananandBurns,1970).Weedmanagementbecomeseasierifacleanfieldwithlittleweedinfestationisselected.Itisimportanttoknowthefieldcharacteristicssuchassoiltestresults,fertility,insect/diseasemanagementhistory,andweedpopulationandinfestationlevel.Understandingthefieldcharacteristicsimprovesefficacyandefficiencyofweedmanagementprograms.Prevention

Weedmanagementshouldbeconductednotonlywithinthefield,butalsoaroundthefields,ditchbanks,andfencelines.Theweedsaroundthefieldcanproduceprolificamountsofseedsandspreadtheinfestationintothefield.Italsoprovidesrefugeforinsects,diseases,andnematodes.Itisimportanttothoroughlycleanequipmentandclothestopreventthetransportofweedseedsintootherfields,especiallyinthecaseofpigweed(orcarelessweed).SeedbedPreparation

Itisbeneficialtotakeadvantageofrainorapplyirrigationtoallowforweedgerminationbeforeseedbedpreparation.Seedbedpreparationshouldbeconductedaftercontrollingtheweedseedlings.Cottonrequiresamoistandfirmseedbedwithgoodseed-to-soilcontact.Properseedbedpreparationallowscottonseedstogerminaterapidly,resultinguniformseedlingemergence.Auniformcottonstandismorecompetitiveagainstweedinfestation.RowDirection

Rowdirectioncaninfluencetheamountofsunlightavailabletoweeds.Whenrowsarearrangedinanorth-southdirection,theremaybegreatershadingofthemiddles.However,importanceshouldbeplacedontheotherpreventativemeasuresasrowdirectionisdependentuponothermanagementfactors,suchastheavailablelengthofrow,slopes,andequipment.RowSpacing

Canopyclosureoccursearlierwithnarrowerrows(<15in)andsolidplantingascomparedtowiderrows(>40in)andskiprowpatterns.Narrowerrowspacingprovideshigherweedsuppressionascomparedtothewiderrowspacingduetothegreatercanopycoverage;however,narrowrowspacingrequiresmoreresourcessuchassoilmoistureandnutrientsthanwiderowspacing.Rowspacingshouldbeproperlyadjustedtotheavailableresourcestoensuremaximumplantgrowthandproduction.QualitySeed

Useofweed-freeseedsisessentialtoreduceintroductionofnewweedspeciesandweedinfestationintheplantingrow.Highqualityseedsalsoprovideadvantagessuchasseedlingdiseaseresistance,highgerminationpercentage,reducedriskforreplanting,rapidanduniformseedlingemergence,andeasierdecisionmakingforweed,insect,anddiseasecontrol.Alltheseadvantageshelptoproduceacompetitivecottonstandagainstweedinfestation.

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VarietySelectionUnlikewheatseeds,cottonseedscannotbesavedforthefollowingyearsduetothepatented

herbicidetolerantandinsectprotectiontraitsofrecentcottonvarietiesunlessconventionalseedsareused.Over90%ofTexascottonproducerspurchasecertifiedseedseachyearwithsingleanddoublestackedherbicidetoleranttraits.Itiscriticalthatproducersknowproblematicweedsintheirfieldssothattheappropriateherbicidetolerantvarietiesmaybeselected.PlantingDate

Cottonplantingisbestdeterminedbysoiltemperaturesinceadequatesoilandairtemperatureimprovesgrowthrateandseedlingvigor,producingacompetitivecottonstandagainstweedinfestations.Favorablesoilconditionsforcottonseedgerminationincludehighsoiloxygenconcentration,adequatesoilmoisture,andsoiltemperaturesabove64°F(BomanandLemon,2005).Optimumplantingdatecanbedeterminedbymeasuringthesoiltemperatureat8-inchdeptheverydayuntilthe10-dayaveragetemperaturebecomes65°F.Cottonplantedearlywithlowsoiltemperatureextendsthegrowingseason;however,thisalsoincreasesriskofstandestablishmentfailurebyslowgrowth,weakseedlingvigor,andweakcompetitivenessagainstweeds.SeedingRate

Plantedseedsandseedlingsareexposedtoasevereenvironment,whereoftenonlyafractionofplantedseedwillbecomematureplants(Gwathmeyetal.,2010).Cottonplantedattoolowaseedingrateincreasestheriskfornon-uniformorthinstands,resultinginyieldlossandreducedharvestefficiency.Cottonplantedattoohighaseedingrateincreasescompetitionamongcottonplantsforwater,nutrients,andsunlight,resultinginlowseedlingvigor.Properseedingrateadjustedtothefieldconditionproducesavigorousanduniformstand.Goodseedlingestablishmentiscriticalforsuccessfulweedmanagement. CropRotation

Croprotationwillhelpreducetargetweedpopulationsgradually.Eachcrophasitsownplantingandgrowingwindows,life-cycle,rootingdepth,leaforientation,andnutrientandmoisturerequirements.Thesecultural,biological,andseasonaldifferencesmodifythefavorableconditionsforweedscreatedundercontinuouscottonproduction,thusnegativelyinfluencingthegrowthandreproductionofsomeweedspecies.Croprotationalsoallowsforrotatingherbicidestotargetproblematicweedspecies.Inaddition,croprotationhasbeenobservedtohaveapositiveeffectonlintyield.Cottonlintyieldwas18to44%higherinthecotton-sorghumrotationsystemthanthecontinuouscottonsystemwhenevaluatedatHalfway,Texas.Thepositiveeffectoftherotationonlintyieldwasevenmorepronouncedinthewaterstressedenvironmentofan8-yearstudyconductedbyTexasAgriLifeResearch(Bordovskyetal.,2011).FieldScouting

Pre-,mid-,andpost-seasonfieldscoutingishighlyrecommendedtokeeprecordsofweedspeciesandinfestationlevel.RefertoapublicationpreparedbyTexasA&MAgriLifeExtension,WeedIdentification:UsingPlantStructuresasaKey,forhelpwhenscoutingfieldsforproblematicweeds.

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PREPLANTBURNDOWN

Akeycomponenttoeffectiveweedmanagementistostartwithacleanfield.Thiscanbeachievedbynormaltillageoperationsandherbicideincorporationsinconventionallytilledfields,orthroughtheuseofpreplantburndownherbicides.Manyherbicideoptionsareavailableforcontrollingemergedweedspriortoplantingaswellasprovidingresidualcontrolofweedsuntilplanting.Alwaysbeawareofplantback(croprotation)restrictionstoavoidcropdamage.RefertoTable2forcurrentrecommendationsforpreplantburndownherbicides.

WEEDMANAGEMENTATPLANTING

Often,themostcompetitiveweedsarethosethatemergebeforeoratthesametimeasthecrop.Thisisparticularlytrueincotton,whichtendstohaveaslowergrowthrateasaseedlingascomparedtoothercrops.Theseearly-seasonweedsareveryeffectiveatcompetingforthesameconsumableresourcessuchaswater,nutrients,andsunlightthatthecottonseedlingneedsforhealthygrowth.Iftheseweedsarenotcontrolled,significantyieldlossescanbeexpected.Witheffectiveearlyseasonweedcontrol,theyieldpotentialofthecropisprotected.Thus,itisimportanttoapplyresidualherbicides(herbicideswithsoilactivity)justpriorto,oratplanting.Theseherbicideswillcontrolweedsbeforetheyemerge,reducingtheneedforpostemergenceherbicideslaterintheseason.Itisimportanttonotethatrainfall,irrigation,ormechanicalincorporationisneededwiththeseresidualherbicidestomovethemintothesoilandactivatethem.RefertoTables3and4forrecommendationsforpreplantincorporated(PPI)andpreemergence(PRE)herbicides.

POSTEMERGENCEWEEDCONTROL

Weedsthatemergeduringtheseasonmustbecontrolledeitherbycultivationorchemicalmeans.Severalherbicideoptionsexistforpostemergence(POST)weedcontrol.WhenapplyingPOSTherbicides,itisvitaltoapplythematthepropertiming,asmanyPOSTherbicideswillonlybeeffectiveifappliedtoverysmallweeds.Thisisespeciallytrueforthepigweedsorcarelessweeds.InadditiontoPOSTherbicides,therearemanyherbicidesavailableforover-the-topordirectedsprayapplicationsthatwillprovideresidualcontrolofweeds.Postdirectedapplicationstakeadvantageoftheeffectivenessofaparticularherbicideonweedsthatmightbeinjurioustothecrop.Directionalorhoodedsprayapplicationsaccomplishthispracticeinadditiontoprovidingresidualcontrol,dependingontheherbicide.Ideally,POSTherbicideswillbeappliedinatankmixwitharesidualpartnertocontrolemergedweedsaswellastoprovideextendedresidualcontrol.Foremergedgrassweeds,severalhighlyeffectivecontroloptionsexistwiththegraminicide(grass-specificherbicides)suchasAssure,Fusilade,Poast,andSelect.Whenapplyingthesegrass-specificherbicides,avoidtankmixtureswithLiberty280SL,whichhavebeenshowntoresultinreducedgrasscontrol.Additionally,tankmixesofthegrassherbicidesandStapleorEnvokeshouldalsobeavoided.RefertoTables5,6,and7forcurrentrecommendationsforpostemergenceover-the-top,post-directed,hooded,andwickorwiperappliedherbicides.

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POST-HARVESTWEEDMANAGEMENT

Afterharvest,therecanbeasubstantialamountoftimeleftforweedgrowthanddevelopmentbeforetemperaturesdroptoalevelunfavorableforwarmseasonweedgrowth,particularlyinsouthTexas.Thus,weedcontrolstrategiesmustbeimplementedtopreventtheproductionofadditionalweedseedthatwillbecomeproblemsduringthenextseason.Inconventionallytilledfields,tillageoperationsprovidegoodcontrolofemergedannualweeds;howeverthisdisturbancealsobringsnewseedsuptothesoilsurface.Intheabsenceoftillage,herbicidesmustbeusedforweedcontrol.Similartochemicalweedmanagementstrategiesduringthegrowingseason,herbicideprogramsafterharvestshouldincludebothpostemergenceandpreemergenceherbicidestocontrolweedsalreadypresentandprovideresidualweedcontrollaterintotheyear.Inaddition,thepost-harvestperiodprovidesanexcellentopportunitytoreducepopulationsofperennialweedsthatmightbepresentatthistime.Applicationofpostemergencesystemicherbicidesatthistimecangreatlyenhancetranslocationoftheherbicidetotherootsystemofperennialplants,improvingchancesfortheirelimination.Whenchoosingaresidualherbicidetoapplyafterharvest,paycloseattentiontoanyplant-backrestrictionsontheproductlabel.

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Table2.Preplantburndownherbicideoptions

WeedsControlledProduct,Rate/A,ActiveIngredient

Group#

TimetoApply Notes

Selectedbroadleafweeds,refertolabel

AimECupto2.0floz(carfentrazone-ethyl)

14Postemergencetoweeds,priortoplanting

Forbestperformance,applytoactivelygrowingweedslessthan4inchestallorrosetteslessthan3inchesindiameter.Maybetankmixedwithglyphosate,glufosinate,paraquat,2,4-D,ordicamba.

Henbit,seedlingdockCaparol4L1.2–1.6pt(prometryn)

5

Fallorwinter,preemergenceorpostemergencetosmallweeds

UseinGulfCoastandBlacklandsonly.Forbestresults,applybeforeweedemergence.Ifhenbithasemergedbutislessthan4to6inchestall,addasurfactantoremulsifiableoil.Forwinterweedcontrolonly;additionalherbicideswillbeneededforspringandsummerweedcontrol.

Annualandperennialbroadleafweeds

Clarity8.0floz(dicamba)

4

Fallorwinterwhenweedsare2–4leafstageandrosettesarelessthan2in.across

Donotapplyinregionsthataveragelessthan25in.precipitationannually.Plantcottononlyafteraminimumof1inchofrainfalloroverheadirrigationand21daysafterapplication.

Manyannualgrassandbroadleafweeds,refertolabelforweed-specificrates

Direx4L0.8–1.6qt(diuron)

7

Preemergenceorpostemergencetoweedslessthan2intall,15to45dayspriortoplanting

Ifapplyingtoemergedweeds,addanonionicsurfactant.Completeanyplannedtillagepriortoapplication,astillageoperationsimmediatelyafterapplicationmaycausecropinjury.

Horseweed,henbit,shepherd’spurse

Envoke0.10oz(trifloxysulfuron)

2 Earlypreplant

CurrentlylabelledinTexasonlyforareaseastofI-35forpreplantuses.Forotherregions,refertothelabelforspecificrestrictions.Applyaloneorintankmixturesforresidualcontrolorsuppression,atleast90dayspriortoplantingcotton.

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Table2continued.preplantburndownherbicideoptions


ETX0.3–1.25floz(pyraflufenethyl)


Applyinaminimumof10gallonswater/Abygroundand5gallonswater/Aaerially.Forbetterresults,add1.0to2.0%cropoilconcentratetospraysolution.UsethehigherCOCrateforlargerlabelledweedsorinlowmoistureconditions.

AnnualbroadleafweedsExpress0.25oz(tribenuron)


Applywhenthemajorityofweedshaveemergedandareactivelygrowing.Allow14daysafterapplicationbeforeplantingcotton.Stressfulconditionsmayweakencottonandresultincropinjury.

Manygrassandbroadleafweeds

FlexstarGT3.0–4.5pt(fomesafen+glyphosate)

14,9Postemergencetoweeds,priortoplanting

OnlylabelledforuseinTexasforareaseastofU.S.Highway77andnorthofStateRoad239,includingallofCalhounCounty.Donotapplytomediumorfinetexturedsoilsascropinjurymayoccur.Moistureisrequiredtoactivatethisherbicideforresidualactivity.

Annualbroadleafweeds

FirstShotSG0.5–0.8oz(thifensulfuron-methyl+tribenuron-methyl)


Allow14daysafterapplicationbeforeplantingcotton.Onlighttexturedsoils,allow21daysbeforeplanting.Maybetank-mixedwithotherherbicidestocontroladditionalweeds.

Manyspecies,refertolabel

Glyphosateproductsratesvary;refertolabel(glyphosate)


Allowatleast2weeksafterapplicationbeforetillage.Whereglyphosateresistantweedsarepresent,addatankmixpartnertocontrolemergedweedsandprovideresidualcontrol.Neverstore,mix,orsprayingalvanizedorunlinedsteeltanks(exceptstainlesssteel).


Goal2XL1.0–2.0pt(oxyfluorfen)

14Preemergenceorpostemergencetoweeds

Someresidualcontrolmaybeexpected.Applytoweedseedlingsnotexceedingfourtrueleaves.Fallowbedsshouldbeworkedthoroughlytoaminimumdepthof2.5inchesbeforeplanting.Donotapplywithin7daysofplanting

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Table2continued.Preplantburndownherbicideoptions

Emergedannualweedsandtopkillsuppressionofperennials

GramoxoneSL2.5–4.0pt(paraquat)

22

Postemergencetoweeds1to6inchestall,priortoplanting

Beforeplanting,preparelandtoallowmaximumweedandgrassemergencebeforetreatment.Plantwithminimalsoildisturbance.Noresidualcontrolwiththisherbicide.Applyinatleast10galwater/Abygroundplus1.0qtnonionicsurfactantper100galspraysolutionor1galcropoilconcentrateper100galspraysolution.Atlowersprayvolumes,useadriftcontrolorspraydepositionadjuvant.Checklabelfortankmixoptions.

AnnualbroadleafweedsHarmony0.3–0.5oz(thifensulfuron)


Maybetankmixedwith2,4-Dorglyphosateherbicidesforincreasedcontrol.Allowatleast7daysafterapplicationbeforeplantingcotton,tankmixtureswithotherherbicidesmayincreasethetimeneededbeforeplanting.Stressfulconditionsmayweakencottonandresultincropinjury.

Manyannualbroadleafweeds,refertolabel

LeadOff1.5–2.0oz(thifensulfuron-methyl+rimsulfuron)

2

Preemergenceorpostemergencetoweeds,priortoplanting

For1.5ozrate,allowatleast30daysbeforeplantingcotton.Forratesof1.5to2.0oz,allow60daysbeforeplanting.Addanonionicsurfactanttospraymixture.Multipletankmixpartnersareavailable,refertolabelformoreinformation.

Manyannualbroadleafandgrassweeds;refertolabel

Liberty280SL22–43floz(glufosinate)

10

Postemergencetoweedsinfallowfields,post-harvest,beforeplanting,orbeforeemergenceofcotton

Spraycoverageiscriticalforperformance,applyinatleast15galwater/Abygroundor10galwater/Aaerially.Seasontotalapplicationsmaynotexceed72or87floz/A,dependingoninitialapplicationrate.Makeapplicationsbetweendawnand2hoursbeforesunsetwithwarm,humidconditionsforimprovedperformance.Makesequentialapplications10to14daysapartasneeded.

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Table2continued.Preplantburndownherbicideoptions

AnnualbroadleafweedsResource2.0–4.0floz(flumiclorac)

14Postemergencetoweeds,priortocottonemergence

Applytoactivelygrowingweedsattheproperstagesofgrowthasindicatedintheproductlabel.Maybecombinedwith2,4-Dorglyphosateherbicides.Applywith1qt/Acropoilconcentrateormethylatedseedoil.Mosteffectivewhenappliedundersunnyconditionsandtemperaturesabove70oF.

Annualandperennialbroadleafandgrassweeds,aswellassedges;refertolabel

Sequence2.0–3.5pt(glyphosate+S-metolachlor)

9,15Postemergencetoweeds

Donotapplytosandorloamysandsoils.Maximumof2.5pt/Aonsandysoilsand3.5pt/Aonmediumandfinesoils.Ifheavyrainfalloccursimmediatelyafterplanting,cropinjurymayoccur,especiallywherepoordrainageoccursortheseedslithasnotbeenproperlyclosed.


Sharpen1.0floz(saflufenacil)

14Postemergencetoactivelygrowingweeds

Formaximumefficacy,usetherecommendedadjuvants,includingMSO+AMSorMSO+UAN.Allow42daysafterapplicationbeforeplantingcotton.Inareaswithlessthan25inchesofannualrainfall,allow42daysbeforeplantingand1inofrainfallorirrigation.Donotapplytosandysoilswithlessthan1.5%organicmatter.CommonlyusedasatankmixpartnerwithglyphosatetobroadenweedspectruminWestTexas.

Annualandperennialbroadleafweeds

2,4-D(6lbai/gal)0.66to2.66pt(2,4-D)


Allowatleast30daysafterapplicationandatleast1inrainfallorirrigationwithina24-hrperiodbeforeplantingcotton.

Selectedweeds,seelabel

ValorSX,Rowel2.0–4.0oz(fallburndown)1.0–2.0oz(springburndown)(flumioxazin)

14

Preemergenceorpostemergencetoweeds,priortoplanting.

Ifweedsareemerged,includeatankmixpartner.Inconventionaltillage,allowatleast30daysand1inchrainfalloroverheadirrigationbetweenapplicationandplanting.Instrip-tillorno-till,allowatleast14daysand1inchofrainfallorirrigationbetweenapplicationandplanting.Includeacropoilconcentrateormethylatedseedoilwithspraysolution.

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Table3.Preplant-incorporatedherbicideoptions


Group#

TimetoApply Notes

Manyannualgrassesandsmall-seededbroadleafweeds

Prowl3.3EC1.2–4.8pt(pendimethalin)

3

Immediatelybeforeplantingorupto140dayspriortoplanting

Incorporateassoonaspossibleandnolaterthan7daysafterapplication.Forincorporation,useanimplementcapableofuniformincorporation1to2inchesdeep.Two-passincorporationwillgivemoreconsistentresults.


ProwlH2O1.0–4.0pt(pendimethalin)

3Upto60daysbeforeplanting

Incorporateuniformlyintotheupper1to2inchesofthesoilbyrainfall,sprinklerirrigation,ormechanicalincorporation.Two-passincorporationwillgivemoreconsistentresults.Donotapplytosoilswithmorethan3%organicmatter.


Treflan(4lbai/gal)1.0–2.5pt(trifluralin)

3AnytimefromOct15untilplanting

Incorporatewithadoubledisk,powerincorporator,fieldcultivator,rollingcultivator,orbedconditioner.Thefirstincorporationshouldoccurwithin24hoursafterapplication.Makeasecondpasswithgrounddrivenequipment.Rollingcultivatorsandbedconditionersshouldonlybeusedoncoursetomediumtexturedsoils.Groundmaybeleftflatorbeddedoverwinter.Iflandisleftflat,takecareduringspringbeddingoperationstopreventturningupuntreatedsoil.Donotapplyinthefalltosoilsthatarewet,inpoorcondition,orsubjecttoflooding.InBrazoria,Calhoun,Chambers,FortBend,Galveston,Harris,Jackson,Jefferson,Liberty,Matagorda,Orange,Waller,andWhartonCounties,ratesof1.5to3.0pt/Acanbeused.DonotuseonanycropgrowninPecosorReevescounties.

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Table3continued.Preplant-incorporatedherbicideoptions


TreflanTR-105.0–12.5lb(conventionaltillage)5.0–20.0lb(conservationtillage)(trifluralin)

3Fallorspringuntilplanting

Two-passincorporationrequired,withthefirstpassoccurringwithin24hoursafterapplication.Forbetterresults,delaythesecondincorporationatleast5daysafterthefirstandrunequipmentinadifferentdirectionthanthefirstincorporation.DonotuseonanycropgrowninPecosorReevesCounties.

15

Table4.Preemergenceherbicideoptions


Group#

TimetoApply Notes


BrakeFX(fluridone+fluometuron)

12,7 Preemergence

Donotuseonsandy,loamysand,orfinesandyloamsoilsinWestTexas.Donotapplymorethan2lbsoffluometuronperacrefromallsources.Donotapplymorethan42floz/AofBrakeFXperyear.Donotapplyinconjunctionwithorganophosphateinsecticides.

Manyannualbroadleafweedsandsomeannualgrasses,refertolabelforweed-specificrates

Caparol4L1.6–4.8pt(prometryn)

5 Preemergence

Donotuseonsandorloamysand.Rainfallorirrigationisrequiredafterapplicationtoobtaingoodweedcontrol.Avoidbroadcastapplicationstocottonplantedinfurrowsmorethan2indeep.Bandapplicationsshouldnotbewiderthanthebottomofthefurrows.Cottonmaybereplantedthroughtreatedsoil,butdonotre-applyproduct.Donotuseinglandlesscottonvarietiestoavoidcropinjury.

Annualgrassesandbroadleafweeds

Command1.33–2.66pt(clomazone)

13 Preemergence

Disulfotonorphorateorganophosphateinsecticidesmustbeappliedin-furrowwiththeseedatplantingwithatleast0.75lbaiasacropsafener,orcropinjurywilloccur.Injurymayoccuronsandysoils.Off-sitemovementofCommandcancausefoliarwhiteningofsomeplants.Avoidsprayingwithin300ftofdesirableplants

Manyannualgrassesandbroadleafweeds,refertolabelforweed-specificrates

Cotoran4L2.0–4.0pt(fluometuron

7

Preemergence,atplanting,orafterapreplantincorporatedapplicationofProwlorTreflan

Activitymaybedelayedorreducedduringdryweather.Donotplantcropsotherthancottonwithin6monthsofthelastapplication.Donotuseonsand,loamysand,orfinesandyloamsoilsnoroncottonplantedinfurrows.Donotfeedfoliagefromtreatedfieldsorgintrashtolivestock.Asuspensibilityagentmaybenecessary.

16

Table4continued.Preemergenceherbicideoptions

Manyannualgrassesandsomesmall-seededbroadleafweeds

DualMagnumorDualIIMagnum1.0–1.33pt(S-metolachlor)

15Preplantincorporatedorpreemergence

Donotapplytosandorloamysandsoils.Donotapplytofurrow-plantedcotton.Applypreemergenceorincorporatenomorethan1inchdeepbefore,at,orafterplanting.Plantcottonatleast1inchdeeponfinesoilsand1.5inchdeeponmediumorcoarsesoils.Forbestcontrolofyellownutsedge,applypreplantincorporated.DonotuseinGainescounty,TX.

Manyannualgrassandbroadleafweeds,refertolabelforweed-specificrates

Direx4L0.8–2.2qt(diuron)orKarmex80DF1.0–2.75lb(diuron)

7 Preemergence

Useonsandyloamorheaviersoils.Donotapplytosandorloamysandsoils.Cottonmaybereplantedthroughthetreatedband,orreworkbedsbeforereplanting.Donotuseonsoilscontaininglessthan1.0%organicmatter.Donotuseasapreplantorpreemergencetreatmentwheresoil-appliedorganophosphateinsecticidesareusedbecauseofthepotentialforseverecropinjury.

Manygrassandbroadleafweeds

FlexstarGT3.0–4.5pt(fomesafen+glyphosate)

9,14 Preemergence

OnlylabelledforuseinTexasforareaseastofU.S.Highway77andnorthofStateRoad239,includingallofCalhounCounty.Donotapplytomediumorfinetexturedsoilsascropinjurymayoccur.Moistureisrequiredtoactivatethisherbicideforresidualactivity.Theglyphosatecomponentofthisproductwillcontrolemergedweeds.

Annualgrassesandsmall-seededbroadleafweeds


3 Preemergence Applyatplantingorupto2daysafterplanting

17

Table4continued.Preemergenceherbicideoptions

Annualbroadleafweeds,suppressionofsomeannualgrasses

Reflex1.0–1.5pt(fomesafen)

14 Preemergence

Applyonlytocoarsetexturedsoils,ascropinjurymayoccuronmediumandfinesoils.OnlylabelledforuseinTexasforareaseastofU.S.Highway77andnorthofStateRoad239,includingallofCalhounCounty.FIFRASection24(c)label:MaybeusedwestofHwy277fromWichitaFallstoAnson,andnorthofHwy180totheNMandOKstatelines.IncludesFisher,Scurry,Borden,andDawsoncounties.Apply1.0pt/Atooverheadbroadcastsprinklerirrigatedcottononly.Aminimumof13inchesofirrigationmustbeappliedthroughAugust31.Rotationalrestrictionsare15to24monthsforwheat,andmorethan36monthsforsorghum.

Grassesandsmall-seededbroadleafweeds

Sequence2.5–3.5pt(S-metolachlor+glyphosate)

9,15Preplantorpreemergence

Donotapplyonsandorloamysoils.Donotexceed2.5pt/Aonsandyloamsoils,or3.5pt/Aonmediumandfinesoils.DonotapplyinGainesCounty.Ifheavyrainfalloccurssoonafterapplication,cropinjurymayoccur,especiallywherewaterstandsorwheretheseedingslitwasnotproperlyclosed.

Selectedbroadleafweeds,seelabelforweed-specificrates

StapleLX1.3–2.1floz(pyrithiobac)

2 Preemergence

Donotapplytosandyorloamysandsoils.Canbecombinedwithdiuron,fluometuron,orprometrynforabroaderspectrumofweedcontrol,seethelabelformoreinformation.Donotapplypreemergenceaerially.

Manyannualgrassesandsomesmall-seededbroadleafweeds

Warrant1.25–2.0qt/A(acetochlor)

15 Preemergence

Seelabelforappropriateratebasedonsoiltexture.Broadcastapplyanddonotincorporate.Cropinjurymayoccurundercoolconditionsandsaturatedsoils.Donotexceed4qt/Afortheseason.

18

Table5.Postemergenceover-the-topherbicideoptions


Group#

TimetoApply Notes

Annualandperennialgrassesincludingbarnyardgrass,bermudagrass,largecrabgrass,johnsongrass,junglerice,andTexasmillet

AssureII5.0–12.0floz(quizalofop)

1Postemergencetoactivelygrowinggrasses

Applicationsmustincludeeither1%v/vcropoilconcentrateor0.25%v/vnonionicsurfactant.Donotcultivatetreatedgrasses7dayspriortoapplicationor7daysafterapplication.Donotapplywithin80daysofharvest.Useaminimumof10galwater/Aundernon-aridconditions,and15galwater/Aunderaridconditions.

SelectedannualbroadleafweedsincludingPalmeramaranth,commoncocklebur,Venicemallow,morningglory,lanceleafsage

Cotoran4L2.0–4.0pt(fluometuron)

7

Postemergencewhencottonisatleast3in.tallandweedsarelessthan2in.

Includeupto0.50%v/vsurfactanttoimproveactivity.Donotfeedfoliageorgintrashtolivestock.MaybecombinedwithMSMAorDSMAforenhancedweedcontroltocottonfrom3in.talltofirstbloom.WestTexas:Donotuseonsandy,loamysand,orfinesandyloamsoils.Donotuseonfurrow-plantedcotton.

Manygrassesandsmall-seededbroadleafweeds

DualIIMagnum1.0–1.33pt(S-metolachlor)

15Postemergencetocotton,beforeweedsemerge

Over-the-topapplicationsmustbemadenolaterthan100daysbeforeharvest.Willneedmechanicalincorporation,rainfall,oroverheadirrigationforactivation.DonotuseinGainesCounty,TX

Selectivecontrolofgrasses,sedges,andbroadleafweedsincludingPalmeramaranthandannualmorningglory(red,ivyleaf)

Envoke0.10–0.15oz(trifloxysulfuron)

2

Postemergencewhencottonhasreachedatleast5trueleaves

Donotapplywithin60daysofharvest.Forover-the-topapplications,donottankmixwithanyotherherbicide,fertilizer,oradditiveotherthanNISasunacceptablecropinjurymayoccur.RefertolabelforregionspecificrecommendationsforTexas.

19

Table5continued.Postemergenceover-the-topherbicideoptionsManyannualandperennialgrassweeds,includingbarnyardgrass,bermudagrass,largecrabgrass,johnsongrass,junglerice,andTexasmillet

FusiladeDX6.0–24floz(fluazifop)

1

Postemergencetoactivelygrowinggrasses,refertolabelforspecificsizerequirements

Donotapplymorethan48floz/Aperseason.Donotapplyafterbollset.Donotharvestwithin90daysofapplication.Donotcultivatefrom7daysbeforeto7daysafterapplication.Cultivation2to3weeksafterapplicationmayprovideenhancedgrasscontrol.

Manyannualandperennialgrassweeds,includingbarnyardgrass,bermudagrass,largecrabgrass,johnsongrass,junglerice,andTexasmillet

Fusion6.0–24.0floz(fluazifop+fenoxaprop)


ForareaseastofI-35,useratesof6.0–12floz.ForareaswestofI-35,ratesare8.0–24floz.Donotapplymorethan24floz/Aperseason.Donotapplytocottonafterbollset.Donotharvestwithin90daysofapplication.Formoreregion-specificinstructions,refertoproductlabel.

Manygrassesandbroadleafweeds

Liberty280SL22–43floz(glufosinate)

10

Postemergenceover-the-toptoglufosinate-tolerantcotton

Useonlyonglufosinate-tolerantcotton.Consultlabelforweed-specificratesandtankmixcombinations.Efficacyisincreasedwithactivelygrowingweeds.Applyinatotalsprayvolumeofatleast10gal/A,15to20gal/Amaybeneededwithdenseweed/cropcanopies.Ifasingleapplicationexceeds29floz/A,theseasonalusemaynotexceed72floz/A,otherwisetheseasonalmaximumis87floz/A.Theadditionofammoniumsulfatemayimproveweedcontrol.WestTexas:smallweeds,43floz/A,andfavorableenvironmentalconditionsarerecommended.

Manygrassesandbroadleafweeds

Glyphosateproductsratesvary,refertolabel(glyphosate

9Postemergencetoactivelygrowingweeds

Useonlyonglyphosate-tolerantcotton.Whereglyphosateresistantweedsarepresent,addatankmixpartnertocontrolemergedweedsandprovideresidualcontrol.Neverstore,mix,orsprayingalvanizedorunlinedsteeltanks(exceptstainlesssteel).

20

Table5continued.Postemergenceover-the-topherbicideoptions

Selectedgrasses,broadleafweeds,andsedges.Refertolabel

MSMA62.66pt(MSMA)

17

Postemergenceover-the-topwhencottonis3to6incheshighoruptoearlyfirstsquarestage

Oneapplicationof2poundsai/Aisallowedperseason,exceptwhensalvageoperationisneeded.Asecondapplicationof2poundsai/Aisallowedforsalvageoperations1to3weeksafterthefirstapplication.Donotfeedtreatedfoliagetolivestock.Someburningandreddishdiscolorationoffoliagemayoccur.

ManyannualgrassandbroadleafweedsincludingPalmeramaranthandcommonwaterhemp.Alsocontrolsriceflatsedgeandyellownutsedge.

OutlookUpto21floz(dimethenamid-P)

15

Postemergencetocottonfrom1sttrueleaftomid-bloom,beforeweedsemerge

Donotapplyoncoarsesoilsclassifiedassandwithlessthan3%organicmatter,andwheregroundwaterislessthan30feetdeep.Donotapplymorethan21floz.Nopreharvestinterval.Outlookmaycausetemporaryinjurytocottonifhighrainfallandsaturatedconditionsoccurduringearlyseedlingdevelopment.


Poast0.75–3.75pt(sethoxydim)


Donotapplymorethan11.25pt/Aperseason.Donotcultivatewithin5daysbeforeor7daysafterapplication.Cultivationnosoonerthan7daysafterapplicationmayimproveseason-longcontrol.Refertolabelforweed-specificuserates.



3Postemergencetocotton,beforeweedsemerge

Onlyapplyover-the-toptocottonbetweenthe4-and8-leafstagesofgrowth.Applicationsmaycausetemporaryinjurytocotton.Postemergenceapplicationswillbemosteffectivewhenrainfalloroverheadirrigationisreceivedafterapplication.Maybetankmixedwithglyphosateonglyphosate-tolerantcotton,andwithglufosinateonglufosinate-tolerantcotton.


Select2EC6.0–16.0floz(clethodim)orSelectMax9–32floz(clethodim)


Useacropoilconcentrateat1%v/v.DonotapplyabroadleafherbicidewithinonedayafterapplicationofSelectorreducedgrasscontrolmayresult.Donotcultivatetreatedgrasses7daysbeforeorafterapplication.

21

Table5continued.Postemergenceover-the-topherbicideoptions

Broadspectrumofannualandperennialweeds,preemergenceactivityongrassesandsmall-seededbroadleafweeds

Sequence2.5–2.75pt(glyphosate+S-metolachlor)

9,15Postemergenceupto10leafstage

Useonlyonglyphosate-tolerantcotton.Ifrainfallorirrigationisnotreceivedwithin7daysofapplication,residualcontrolmaybereduced.Donotexceed2.5pt/Aoncottonwithlessthan5leaves.Donotharvestwithin100daysofapplication.Donotincludeammoniumsulfate.DonotuseinGainesCounty.

ManyannualbroadleafweedsincludingPalmeramaranthandannualmorningglory,seelabelforweed-specificrates

StapleLX2.6–3.8floz(pyrithiobac)

2

Postemergencetomostweedswhentheyare1-2inchestall,refertolabel

Useanonionicsurfactantatarateof0.25–0.5%v/v,oracropoilconcentrateat1.0–2.0%v/v.ForareaswestofHighway83onsandorloamysandsoilswithlessthan1.0%organicmatter,limitapplicationstoonein-seasonapplicationofabandofnomorethanone-thirdtherowwidth.Ifreplantingcottonisnecessary,plantoutsidethetreatedband.

Preemergenceactivityonannualgrassesandsmall-seededbroadleafweeds

Warrant1.25–2.0qt(acetochlor)

15

Postemergencetocotton,beforeweedsemergeandcottonreachesfirstbloom

Optimumtimingandrateis2-to3-leafcottonpriortoweedemergenceat1.5qt/A.Foremergedweeds,addapostemergenceherbicide.Ifnorainfallorirrigationoccurswithin10days,shallowincorporationwillbenecessary.Donotmixwithfertilizer,asseverecropinjurymayoccur.

22

Table6.Post-directedorhoodedherbicideoptions


Group#

TimetoApply Notes

Commonlambsquarters,ivyleafandpittedmorningglory,redrootpigweed,velvetleaf,andcommonwaterhemp

AnthemFlex2.73–3.80floz(pyroxasulfone+carfentrazone)

14,15

Postemergenceasadirectedspraytocottonfrom6in.talltofirstbloom,orapplyatlayby.

Applytocommonwaterhemplessthan2in.tall,morninggloryupto3leaves,andlambsquartersupto3in.tall.Forotherlabelledweeds,applybeforetheyreach4in.inheight.Theuseofanadjuvantisrecommendedforconsistentcontrol.

Annualgrassesandbroadleafweedsincludingcocklebur,devil’sclaw,commonlambsquarters,morningglory,piemelon,andpigweeds

Caparol4L1.6–3.2pt(prometryn)

5

Postemergenceasadirectedspraywhencottonisatleast12in.tallandweedsarelessthan2in.tall

IntheHighPlains,1.6to2.4pt/Aissufficient.Donottreatcottonthatisstressedduetodrought,cultivatordamage,orfertilizerapplications.Whenapplyingtoemergedweeds,add2qtsurfactantper100galofspraysolution.DonotuseintheRioGrandeValley.

Manyannualbroadleafweeds,includingPalmeramaranth,devil’sclaw

Cobra12.5floz(lactofen)

14

Postemergencedirectedtocottonover6to8in.tall,orapplyatlayby.

Theadditionof2ptnonionicsurfactantor0.5to1.0ptcropoilconcentrateper100galofspraysolutionconsistentlyenhancedweedcontrol.Refertolabelforspecificapplicationinstructionsforindividualweedspecies.

Manyannualgrassesandbroadleafweeds,refertolabelforweed-specificrates

Direx4L0.4–0.6qt(diuron)orKarmex80DF0.25–0.5lb(diuron)

7

Postemergencedirectedaftercottonis6to12in.tall,asneededupto2applications

Sprayyoung,activelygrowingweedslessthan2in.tall.Providesresidualcontrolofmanyweeds.Addasurfactanttospraysolution.Seelabelforweedandratespecifics.

Selectedannualgrassesandbroadleafweedsincludingcocklebur,morningglory,pigweed,smellmelon

Envoke0.10–0.25oz(trifloxysulfuron)

2Postemergencedirectedtocottonover6in.tall

Addnonionicsurfactantat0.25%v/vorcropoilconcentrateat0.5to1.0%v/v.Donotharvestfor60daysafterapplication.RefertolabelforregionspecificrecommendationsforTexas.

23

Table6continued.Post-directedorhoodedherbicideoptions

Annualbroadleafweedsincludingcocklebur,lambsquarters,morningglory,pigweed

Fierce3oz(flumioxazin+pyroxasulfone)

14,15

Postemergencethroughhoodedorshieldedsprayersaftercottonis6in.tall,oratlaybyaftercottonis16in.tall.

Applytoactivelygrowingweedsattheproperstageofgrowthasindicatedonthelabel.MaybecombinedwithMSMA,diuron,orglyphosate.Mosteffectivewhenappliedundersunnyconditionsattemperaturesabove65oF.

Annualgrassesandbroadleafweedsincludingcocklebur,devil’sclaw,lambsquarters,morningglory,piemelon,pigweed

Goal2XL1.0–2.0pt(oxyfluorfen)

14Postemergencedirectedtocotton6to8in.tall

Foroptimalcontrol,apply2.0pt/Atoactivelygrowingweedswithnomorethan4trueleaves.Weedsatthe2to3leafstagecanusuallybecontrolledatthe1.0pt/Arate.Donotusehollowconenozzles.

Annualgrassesandbroadleafweedsincludingcocklebur,lambsquarters,pigweed,smellmelon

LaybyPro1.0–2.4pt(linuron+diuron)

7Postemergencedirectedtocottonatleast8in.tall

Forcotton8to15in.tall,applyratesof1.0to1.5pt/A.Forcottontallerthan15in.,ratesashighas2.4pt/Amaybeapplied,dependingonsoiltexture.

Annualgrassesandbroadleafweedsincludingcocklebur,devil’sclaw,lambsquarters,morningglory,piemelon,pigweed

Linex4L1.0–3.0pt(linuron)

7Postemergencedirectedtocottonatleast12in.tall

Ratesvarybasedupontheheightofcotton,refertolabelformoreinstructions.Add1.0ptsurfactantforeach25galofspraysolution.

Selectedgrasses,broadleafweeds,andsedges.Refertolabel

MSMA62.66pt(MSMA)

17

Postemergencedirectedtocottonbetween3in.tallandfirstbloom.

Applyat40galwater/A.Ifregrowthoccurs,asecondapplicationmaybemade1to3weeksafterthefirst.Donotapplyafterfirstbloom.Donotfeedtreatedfoliagetolivestock.

Preemergencecontrolofmanyannualgrassesandsmall-seededbroadleafweeds,postemergencecontrolofbroadleafandsomegrassweeds

Prefix2.0–2.33pt(S-metolachlor+fomesafen)

14,15Postemergencedirectedtocottonatleast6in.tall

Applytobroadleafweedswith2to4trueleavesinaminimumof10galwater/A.Addanonionicsurfactantat0.25to0.50%v/voracropoilconcentrateat1.0%v/v.Donotaddliquidnitrogenfertilizer.InTexas,onlyuseinareaseastofU.S.Highway77andnorthofStateRoad239,includingallofCalhounCounty.

24




3Postemergencedirectedtocottonafterlayby

Rateof1to3pt/Aonconventionalorminimaltillage,2to4pt/Aonno-till.Checklabelformaximumlabelledratesbaseduponsoiltexture.

Annualandperennialgrassandbroadleafweeds

Glyphosateproductsratesvaried,refertolabel(glyphosate)

9

Postemergenceusinghoodedsprayerstonon-glyphosatetolerantcotton

Applyin20to30galwater/A.Extremecaremustbetakentopreventcontactofglyphosatewithfoliageofnon-glyphosatetolerantcotton.

Annualbroadleafweeds,suppressionofsomeannualgrasses

Reflex1.0–1.5pt(fomesafen)

14

Postemergencedirectedtocottonfrom6to12inchestall,orasalaybytocottonwithatleast4inchesofbarkonstem

Applyonlytocoarsetexturedsoils,ascropinjurymayoccuronmediumandfinesoils.OnlylabelledforuseinTexasforareaseastofU.S.Highway77andnorthofStateRoad239,includingallofCalhounCounty.FIFRASection24(c)label:MaybeusedwestofHwy277fromWichitaFallstoAnson,andnorthofHwy180totheNMandOKstatelines.IncludesFisher,Scurry,Borden,andDawsoncounties.Apply1.0pt/Ainatleast10gal/Aspraysolution.ApplicationsmaybemadeuptoJuly10.Include0.25%v/vnonionicsurfactantor1.0%v/vcropoilconcentrate.Rotationalrestrictionsare24monthsforwheat,andmorethan36monthsforsorghum.

SedgesandbroadleafweedsSandea0.66–1.33oz(halosulfuron)

2

Postemergenceusinghoodedsprayeranytimeaftercottonemergenceuntilrowclosurebycotton

Providesbothpreemergenceandpostemergenceweedcontrolofsusceptiblespecies.Forcontrolofemergedweeds,treatwhenactivelygrowingand1–3in.inheight.Addanonionicsurfactantat0.25to0.50%v/v.Donotapplymorethan1.33ozperseason.

25


Selectedbroadleafweeds,grasses,sedges

Suprend1.0–1.5lb(prometryn+trifloxysulfuron)

2,5Postemergencedirectedtocottonatleast6in.tall

ForuseinpickerandPimacottonvarietiesonly.DonotapplyintheRioGrandeValley.Donotapplywithin60daysofcottonharvest.Donotexceed2.7lb/ASuprendperseason.


Treflan4EC1.0–2.0pt(trifluralin)

3

Postemergencedirectedtocottonfrom4leafstagetolayby

Soilincorporateusingonepassofasweep-typecultivatororaproperlyadjustedrollingcultivator.Donotharvestwithin90daysofapplication.

ManyannualbroadleafwedsValorSX1.0–2.0oz(flumioxazin)

14

Postemergencedirectedthroughhoodedorshieldedsprayers,ordirectedsprayatlayby

Forhoodedorshieldedsprayerapplications,applyonlytocottonthatisatleast6in.tall.Laybyapplicationsmaybemadeaftercottonreaches16in.height.Onlyuseanonionicsurfactant.Cropoilconcentratesormethylatedseedoilsmayresultinseverecropinjury.

Annualgrasses,sedges,andannualbroadleafweeds

Zidua0.75–2.1oz(pyroxasulfone)

15

Postemergencedirectedtocottonbetween5leafstageandfirstbloom

SomecottoninjurymaybeobservedwhenZiduaisappliedunderstressfulconditions.Willonlycontrolweedsemergingafterapplication.Donotuseoncoarsetexturedsoils.

26

Table7.Wickorwiperappliedherbicideoptions


Group#

TimetoApply Notes

Manyannualandperennialgrassandbroadleafweeds

RoundupWeatherMAX33-75%solution(glyphosate)

9Whenweedsareatleast6in.abovethecottoncrop.

Donotwipeanycloserthan2in.abovethecottoncrop.Asweeddensityincreases,reducespeed.Wipingasecondtimeintheoppositedirectionmayimprovecontrol.Donotusewiperwhenweedsarewet.Oversaturationofwipermaycausedrippingwhichwillinjurethecrop.Concentrationusedishighlydependentonthewickorwiperdevicechosen,consultmanufacturer.

27

PHOTOGRAPHSOFCOMMONWEEDS

BalloonvineCardiospermumhalicacabum

Annualvinesprawlingandtrailing.Leavesalternate,usuallytwicealternatelycompound.Leafletstoothedandlobed.Flowersabout4mmlongwith4petals.Fruitsinflated(balloon-like).

BarnyardgrassEchinochloacrus-galliAnnualsummergrass.Leafsheathandbladehairlesswithnoliguleorauricles.Stemsflattened.Spikelets3to4mmlong.

Bindweed,fieldConvolvulusarvensisPerennialtrailingvinewithdeeproot.Gray-greenpubescence.Simple,alternateleaves,usuallylanceolateinshape.Flowerstypicallywhitewithfivefusedpetals.

28

BrowntoppanicumUrochloafasciculatumAnnualsummergrass.Spreadingorerectgrowthformspossible.Ligulesofhairsapproximately1mmlong.Panicleswithappressedbranches.

CommoncockleburXanthiumstrumariumSummerannual.Smooth,waxycotyledonslanceolateinshape.Alternateleavestriangularorovateinshapewitharough,sandpapertexture.

CommonsunflowerHelianthusannuusSummerannual.Ovatecotyledons.Alternatesimpleleaveswithroughtextureandhairs.Leaveswithserratemarginstaperedtoapoint.

29

CutleafgroundcherryPhysalisangulateSummerannual.Mostlywithouthairs.Leavesovatetoovate-lanceolatewithtoothedmargins.Paleyellowflowers5-sided.Stemangledincross-sectionandhollow.

Devil’sclawProboscidealouisianicaLow,bushysummerannual.Odiferousandcoveredwithglandularhairs.Leavesalternateoroppositeandmostlyovateinshape.Yellowfive-lobedflowers.Fruitafleshycurvedpod,splittingintotwo“claws”afterdesiccation.

HophornbeamcopperleafAcalyphaostryifoliaErectannual,freelybranched.Long-petioledleaves,nearlyglabrous.Leavesalternatewithfinelytoothedmargins.

30

HorseweedConyzacanadensisWinterorsummerannual.Smooth,spatulatecotyledons.Earlyleaveswithentiremargins,laterleavescrowdedaroundthestemwithentireortoothedmarginsandoftenhairy.

IvyleafmorninggloryIpomoeahederaceaAnnualtwiningvinewithpubescentstems.Leavestypically3-lobed,occasionallywithoutlobes.Funnel-shapedflowers(corolla),typicallylightbluewithwhiteoryellowcenters.

JohnsongrassSorghumhalepensePerennialgrass.Leafsheathandbladehairlesswithnoauricles.Largemembranousliguleswithjaggedmargins.Oval,shinyseed.Mayalsoreproduceviarhizomes.

31

JunglericeEchinochloacolonaSummerannualgrass.VerysimilarinappearancetoE.crus-galli(barnyardgrass).Leavesmayexhibitseveralpurplebandsacrossthem.

KochiaKochiascopariaSummerannual.Narrow,oblongcotyledonswithmanysoft,finehairs.Leavesalternateandsimplewithmanyhairs,andwithoutpetioles.

LanceleafSageSalviareflexaSlightlyhairyannualreaching1to1.5fttall.Oppositeleaveslanceolatewithtoothedorentiremarginsandshortpetioles.Stemssquareincross-section.Flowerswithbluetowhitepetals.

32

Nutsedge,yellowCyperusesculentusPerennial,colonialsedge.Stemstriangularincross-section.Leavesarrangedinranksofthreeandgraduallyformapointedtip.Rhizomessometimeswithtubersformingattheends.

Nutsedge,purpleCyperusrotundusPerennial,colonialsedge.Stemstriangularincross-section.LeavesarrangedinranksofthreeandformamoreroundedtipthanC.esculentus(yellownutsedge).Rhizomesmayformchainsoftubersalongtheirlength.

PalmeramaranthAmaranthuspalmeriDioecioussummerannual.Cotyledonslinearandwithouthairs.Leavesmostlyglabrous.Petiolesoftenlongerthanleafblades.Faintwhitechevronmarkingsmaybepresentonleaves.

33

PartheniumragweedPartheniumhysterophorusAnnualbroadleafresemblingtheappearanceofwesternragweed.Seedlingformsabasalrosette,whichlatergrowsto0.5–1.5mtall.Stemslongitudinallygroovedwithstiffhairs.Laterleavesarealternateanddeeplydivided.Flowersarewhiteandforminnumerousclusters.

PuncturevineTribulusterrestrisProstrateannualbroadleaf.Leavespinnatelycompoundandopposite.Leafletspubescentatthemidveinandmarginsabove,denselypubescentbelow.Flowerswith5yellowpetals.Fruitisaspinycapsule.

Purslane,commonPortulacaoleraceaSprawlingsummerannual.Cotyledonslinearandwithouthairs.Oppositeleaveswhicharesmoothandspatulate.Leavesandstemsaresucculent.

34

ProstrateSpurgeChamaesyceprostrataSprawling,prostrateannual.Leafbladesbroadlyelliptic,withshortornopetioles,andarrangedopposite.Leavesfoldingtogetheratnightorunderpoorconditions.Brokentissueexudesamilkysap.

RussianThistle,tumbleweedSalsolaibericaBushyannual.Stemsmayhavered-purplestreaks.Leavesarefiliform.Flowerslackpetalsandaresubtendedbyapairofspinybracts.Theplantdriesandbreaksoffatthebaseinthefall,formingaround“tumbleweed.”

SharppodmorninggloryIpomoeatrichocarpaPerennialvinewithtwining,climbingstems.Leavesalternatewithpubescence,typically3-lobedorheart-shaped(chordate).Flowersusuallyredtored-purplewithadarkredcenter.

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SilverleafNightshadeSolanumeleagnifoliumPerennialbroadleaf.Stemsandleaveshaveasilverappearanceduetomanystellatehairs.Stemsmaybedenselyprickly.Leavesarelinear.Flowersblue-purple,occasionallywhite.

TexasBlueweedHelianthusciliarisPerennialwithslenderrhizomes.Stemsandleaveswithablue-greencast.Leavesaremostlyopposite,lanceolate,withshortpetioles.Rayflowersyellow,diskflowersreddish-bronze.

TexaspanicumUrochloatexanaAnnualgrass,spreadingtoerectingrowthhabit.Ligulesofhairsapproximately1mmlong.Broad,hairyleaves.Panicleswithappressedbranches.SimilarinappearancetoU.fasciculate(browntoppanicum),exceptforslightlyshorterpubescenceonleaves.

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Waterhemp,commonAmaranthusrudisSummerannual.Linearcotyledons.Leavesnarrowlyovatetolanceolate,alternate,andwaxyinappearance.Plantwithouthairs.Petiolesmaybeshorterthanleaves.

WoolyleafBursageAmbrosiagrayiPerennialreaching6to24inchestall.Pinnatelylobedleaves,oppositeinarrangement,withagraycastduetodensepubescence.Fruitbecomesaburaftermaturity.

VelvetleafAbutilontheophrastiSummerannual.Eachcotyledondiffersinshape;oneisovate,whiletheotherischordate(heart-shaped).Bothcotyledonswithentiremarginsandcoveredinshorthairs.Stemsaredenselyhairy.Leaveschordate,andalternatewithsoft,velvetyhairysurfaces.

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DepartmentofSoilandCropSciencesTexasA&MAgriLifeExtensionService

TexasA&MUniversity

http://soilcrop.tamu.edu

.

Informationgivenhereinisforeducationalpurposesonly.ReferencetocommercialproductsortradenamesismadewiththeunderstandingthatnodiscriminationisintendedandnoendorsementbyTexasA&MAgriLifeExtensionServiceisimplied,noristhereanyimplicationthatotherformulationscontainingthesameactiveingredientarenotequallyeffective.Thispublicationisnosubstitutefortheherbicideproductlabels,itisintendedtoserveonlyasaguideforcontrollingweedsincotton.Labelledratesand

restrictionschangeconstantly;therefore,consulttheproductlabelbeforeuse.

EducationalprogramsoftheTexasA&MAgriLifeExtensionServiceareopentoallpeoplewithoutregardtorace,color,religion,sex,nationalorigin,age,disability,geneticinformation,orveteranstatus.

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Cooperating.

weed management in texas cottoncotton.tamu.edu/weed management/cotton weed control 042016.pdf ·...

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