HowHopHerbicidesWorkJedColquhoun

UniversityofWisconsin-Madison

HowHopHerbicidesWork

• Hopherbicides(exampletradenames):– norflurazon (Solicam)– trifluralin (Treflan)– flumioxazin (Chateau)– carfentrazone (Aim)– glyphosate(Roundup)– 2,4-D– clethodim (Select)Pesticide labels changeoftenandvaryregionally. Asalways,readandfollowthepesticide label priortouse.Theinformation inthispresentation isnota

substitute forthe label– the label isthe law!

HowHopHerbicidesWork

• Hopherbicides:– Whatthey’reusedfor

inhops– Howtheywork,not

inatextbookwaybutsothattheyworkbest

– Anyissuestokeepaneyeoutfor

HowHopHerbicidesWork

norflurazon (Solicam)

• PREherbicide:applytocleansoilaftertillageinfallorearlyspring

• Controlsseveralbroadleavesandgrasses• Applyasadirectedspraytothesoiloneachsideoftherow

• Apply6monthsormoreaftercropplanting• 60daypre-harvestinterval

norflurazon (Solicam)

• Uptake:primarilyroots• Translocation:tothegrowingpoints• Plantsystemaffected:

– Blockspigmentformation– Toxicbyproductsbuildupinplant– Cellmembranesaredestroyed

• Selectivity:tolerantplantshavelessuptakeandmoremetabolism

norflurazon (Solicam)

trifluralin (ex:Treflan)

• Controlsseveralannualgrassesandafewbroadleafweeds

• PREcontrolonly– emergedweedsnottouched

• Needstobeincorporated1to2inchesdeep,butdon’tdamagethehopcrowns

• Don’tsprayordragtreatedsoiloverhopcrowns– emergencewillbedelayed

trifluralin (ex:Treflan)

• Uptake:rootsofnearbygerminatingweeds• Translocation:torootgrowingpoints• Plantsystemaffected:

– Celldivisioninroottipsisdisrupted• Selectivity:tolerantplantshavelessuptake,lesstranslocationandmoremetabolism

trifluralin (ex:Treflan)

trifluralin (ex:Treflan)

carfentrazone (AimEC)

• AvailableinWIonaSpecialLocalNeedslabel• Forsuckercontrolandforyoungbroadleafemergedweeds– Suckers:applytothebottom1.5ft andtosuckermat.Seelabelforadjuvantrequirements

– Newly-emergedbroadleafweeds:Applyusingashieldedorhoodedsprayer• Avoidnewlytrainedhopbinesuntilsufficientbarkinganduntiltheyaretallenoughtoavoidtheapicalbud

flumioxazin (ChateauSW)

• ForsuckercontrolandforPREweedcontrol– Suckers:Applyasadirectedsprayafterthehopbinesareatleast6ft tall• Spraythelower2ft ofhops

– PREweedcontrol:Applytodormanthopsasaband1to1.5ft fromtherow• Controlsseveralbroadleavesandsomegrasses• Don’tusewithanadjuvant• Avoidcontactwithhops

flumioxazin (ChateauSW)andcarfentrazone (AimEC)

• Uptake:rootsandshootsforChateau;shootsforAim

• Translocation:somewithChateau;almostnonewithAim

• Plantsystemaffected:– Cellmembranesaredestroyedandcellscollapse

• Selectivity:tolerantplantsmetabolizetheherbicides

Chateau Aim

carfentrazone (AimEC)

glyphosate(ex:Roundup)

• Non-selective:whatyouspraywillbeinjuredorkilled,includingthehops!

• Post-emergent– nosoilresidual• Canbeappliedasarowmiddle,shielded,wiper,directedorspottreatment– Don’tletitcontactthehops– removesuckersintheareapriortoapplicationifneeded

– 14daypre-harvestinterval

glyphosate(ex:Roundup)

• Uptake:onlybyshoots,notbyroots

• Translocation:totheactivesinkintheplant

• Plantsystemaffected:– Aminoacidproduction

• Selectivity:Non-selective!Roundupinjuresorkillsmostplantsthatittouches!

glyphosate(ex:Roundup)

Susceptible: 1 pint/Acre (21 DAT)

Oregon:1pint/Acre

Oregon:4pints/Acre

Oregon:8pints/Acre

Glyphosateresistanceupdate

• Commonwaterhemp:– EauClaireCounty:10x

resistance– PierceCounty:13x

resistance

• Palmeramaranth:– DaneCounty

• Previouslyidentified:– Giantragweed– Horseweed

Slide source: V. Davis

Herbicide-ResistantPalmerAmaranthCasesinWisconsin

ConfirmedGlyphosateResistanceSuspectedGlyphosateResistance

NoConfirmedResistance

SuspectedHPPD- andALS-InhibitorResistance

* *TestedbyamolecularassayfromUIUC

(MapbyT.R.Butts,slidebyD.Hammer)

Herbicide-ResistantCommonWaterhempCasesinWisconsin

ConfirmedGlyphosateResistance

SuspectedGlyphosateResistance

NoConfirmedResistance

SuspectedGlyphosate&PPO-InhibitorResistance

(MapbyT.R.Butts,slidebyD.Hammer)

*

* * *TestedbyamolecularassayfromUIUC

**

**

Source:Pratt et al., Iowa State University, 1999

2,4-D(severaltradenames)

• Post-emergentbroadleafweedcontrol• Makedirectedapplicationstorowmiddles• Canmakeupto3applications,butwithatleast30daysbetweenapplications

• 28daypre-harvestinterval• Don’tcontactgreenhopstemsorfoliage

2,4-D(severaltradenames)

• Uptake:shootsandfoliage• Translocation:tothegrowingpoints• Plantsystemaffected:

– Planthormones:unbalancedandoverloaded• Selectivity:grassesuptakeandtransport2,4-Dlesseffectivelyandmetabolizeitquickly;differencesinbroadleafcontrolbasedonmetabolismrate

2,4-D(severaltradenames)

2,4-D

Didyoucatchmydrift?

clethodim (ex:Select)

• Post-emergentgrasscontrol– Controlsmostannualsandsomeperennials– Nobroadleafweedcontrol

• Applytoactivelygrowinggrasses• Includeanadjuvantasdirectedbythelabel• 21daypre-harvestinterval

clethodim (ex:Select)

• Uptake:shootsandfoliage• Translocation:tothegrowingpoints• Plantsystemaffected:

– ACCase enzymeisblocked• Selectivity:grasseshaveanactiveACCaseenzyme;broadleafplantsdon’t

clethodim (ex:Select)

clethodim (ex:Select)