Hop insects and diseases

DianeBrown,MichiganStateUniversityExtension

diseasestokeepoutofyourhopyard Virusesandviroids

useplantingmaterialcertifiedfreeofHSVd andothervirusesisthebestlineofdefense.

Purchasevirusindexedstock. Theprimarymeansofspreadisbypropagationfrominfectedplants.

Unintentionalpropagationfrominfectedrootpiecescananddoesoccur

maytake3to5growingseasonsbeforeobvioussymptomsofthediseaseappear.

ApplemosaicvirusDavidGent,USDAAgriculturalResearchService,Bugwood.org

VirustestingresultsforhopsinSWMRECtestplotsgrownfrom

rhizomes

Virustestinglabforhopsamples:ELISAlab,24106N.BunnRd.ProsserWAhttp://healthyplants.wsu.edu/contactinformation/

ManagementofHpSVd Manyplantsare

symptomless Makesureplanting

materialarefreefromHpSVdknowyoursource!

Canbespreadplanttoplantmechanically bymowingorpruning,leafstripping

Viroidispresentinplantsap;cansurviveinroots>1yr,3mo.inplantdebris Fociofinfectedhopplants

http://www.fu.gov.si/en/services_and_measures/regulated_organisms/hop_stunt_viroid/graphical_material/

ManagementofHpSVd Testforpresenceofviroid Removeandreplantif

possible Performfieldoperations

inHpSVd freehopyardsfirst

Decontaminateequipmentbetweenyards10%bleachfor10min.

SymptomsoninfectedGlacierhop

Photos:CompendiumofHopDiseasesandPests

ManagementofHpSVd

Usingcontactherbicidestoholdbackvigorousnewannualgrowthinspringuntilthepropertrainingdateforthatvarietyandremoveweakshootsinthespringispreferabletotheuseofmechanicalmowersthatmaytransmittheviroid.

Removingbasalvegetationlaterintheseasonbychemicalratherthanmechanicalmeansalsoreducestheriskoftransmission.

DelayinspringplantgrowthofHSVrd infectedbines

Shortinternodesandpoorleafdevelopment

CrackingofbinesinfectedwithHSVrd

Stunted,poorgrowth,binesunwindduetodisturbanceofhookedclimbinghairs

http://www.fu.gov.si/en/services_and_measures/regulated_organisms/hop_stunt_viroid/graphical_material/

HopmosaicvirusHpMV

Transmittedbyaphids damsonhop,greenpeach Propagation,rootgrafts, Oftensymptomless mostseriousonvarietiesderivedfromGoldings

Photos:CompendiumofHopDiseasesandPests

Applemosaicvirus

Canreduceconewt.by50% CanreduceAAcontentby10% Maybesymptomless Spreadsbyplanttoplantcontact,infectedsap,androotgrafts

Usevirusindexedplants

SymptomsonNugget

SymptomsonColumbus

Photos:CompendiumofHopDiseasesandPests

HopsCleanPlantNetwork

Hopsourcematerialistestedinitiallyfor: Americanhoplatentvirus* Applefruitcrinkleviroid(notknowntooccurinNorthAmerica) Applemosaicvirus*(a.k.a.Prunus necroticringspot virushop

isolate) Arabis mosaicvirus Hoplatentviroid Hoplatentvirus* Hopmosaicvirus* Hopstuntviroid* Strawberrylatentringspot virus Phytoplasma Growninmeristemculture,tested3xmoretimesfor*viruses

HopsCleanPlantNetwork

website:http://healthyplants.wsu.edu/hopprogramatcpcnw/

http://healthyplants.wsu.edu/hopprogramatcpcnw/purchasinghopmaterial/

Growinghopsfromhealthyunrooted cuttings:http://healthyplants.wsu.edu/hopprogramatcpcnw/growinghopsfromunrootedcuttings/

Hopcystnematode(Heteroderahumuli)

ReportedinMichigan mostcommonplantparasiticnematode

foundonhops. U.S.,Canada,Europe,NewZealand,

Australiaandotherlocations. foundinthesoilandinandonhoproots. Thereare12generationsperyear. Thecystsarebrowntoblack,lemonshapedandsmaller

thantheheadofapin. Malesaretransparentandlessthan1/25thofaninchlong. Femalesarecreamcoloredandlemonshapedandabout

1/50thofaninchlong.

Cystscontainingeggs

Photos:CompendiumofHopDiseasesandPests

cystnematodelifecycle,www.plantpath.iastate.edu

Hoproot

overwintering

Hopcystnematode

spring

EarlysummerJ2of2nd gen.

12generations/year

Hopcystnematode Cancausehopyield

decreaseof50%anddeteriorationofquality.

Lossesdependonthenematodepopulationdensitythisinsoilinspringandonplantgrowthstage.

Adecreaseinthesurvivabilityofhopcuttingshasbeenalsorecorded

Mayinteractwithverticillium wiltfungus

Verticillium wilt

DavidGent,USDAAgriculturalResearchService,Bugwood.org

Causedbyafungus Soilborne Formmicrosclerotia inthesoil Multiplehosts Canliveforlongperiodsinthesoil

Verticillium wilt

DavidGent,USDAAgriculturalResearchService,Bugwood.org

Noeffectivechemicalcontrols

Croprotation 4yearsgrasses

Rogueinfectedplants Limitnitrogen Reducedtillage Removecropdebris

Crowngall Agrobacteriumtumefaciens Causedbyasoilinhabitingbacterium Broadhostrange Ofmostconcerninnewplantings

GallsymptomsonbinesandcrownsPhotos:CompendiumofHopDiseasesandPests

Crowngall Agrobacteriumtumefaciens InfectionthroughwoundsFrostinjuryormechanical

Spreadplantingstock,irrigationwater,cuttingtools

Survivesininfestedsoil,plantdebris,

GallsymptomsonbinesandcrownsPhotos:CompendiumofHopDiseasesandPests

Crowngall Agrobacteriumtumefaciens Usehealthyplantingstock Removeanddestroyinfectedplants Galltrol somereportedeffectivenessonaerialstems

GallsymptomsonbinesandcrownsPhotos:CompendiumofHopDiseasesandPests

Managementofsomecommonhopinsects,mitesanddiseases

2spottedspidermites Hopaphids Japanesebeetles Potatoleafhopper Downymildew Powderymildew

Thelabelisthelaw

Itisaviolationofthelawtodisregardlabeldirections.

Alwaysreadthelabelbeforeusinganypesticide. You,thegrower,areresponsibleforsafepesticideuse.Trade(brand)namesareprovidedforyourreferenceonly.

Nodiscriminationisintended,andotherpesticideswiththesameactiveingredientmaybesuitable.

Noendorsementisimplied.

Managingresistance

Rotatemodesofaction FRACcodes IRACcodes Followlabeldirectionsforresistancemanagement

Tankmixeswithmultisitepartners Recognizesignsofpestresistance Suddenorgraduallossofcontrol

Malespidermite,nymphwithegg

FemalespidermitesPhotos:Compendiumofhopdiseasesandpests

Photos:Compendiumofhopdiseasesandpests

Spidermites

Femalesoverwinterincrowns,cracksinhoppoles

layeggsinspringbothmaleandfemale Nymphshavetwomoltstobecomeadults 13weeks/generationdependingontemperatures

Twospottedspidermite

Sampleregularly,beginninginlateMayorearlierifweatherisverydry.2leavesfrom20plants

Miticides:Usehighvolumeapplicationstoensurecompletecoverage.

ThresholdsfromPacificNorthwestProvisionalthresholdis

2adults/leafJune 5to10mites/leafmidJuly

Twospottedspidermites AbamectinRUP6

AgriMekmustusewithnonionicsurfactant EpiMek Temprano ABBA

Brigade(bifenthrin)RUP 3A Brigadier(bifenthrin/imidacloprid)RUP3A/4A MANADicofol4E REIis29daysUN Acramite(bifenazate)UN Savey50DF(hexythiazox)10A

Twospottedspidermites Fujimite(fenpyroximate)XLO21A Envidor(spirodiclofen)23 Wettablesulfur checklabelforOMRIapproval Acoidal,CosavetDF,Kulumus,MicrothiolDisperssareOMRIlabeled

PureSprayGreen,OmniSupremeSpray,Suffoilx(mineraloil)MOMRI

Desexinsecticialsoap,MpedepotassiumsaltsoffattyacidsMOMRI

Trilogy(azadiractin)UNOMRI Ecotec(rosemaryoilandpeppermintoil)OMRI

PLH PLHwillbefoundontheundersideofleavessoflipleavesandshootsover

GrowersmayalsochosetoplacetwosidedyellowstickytrapsinthefieldtocatchPLH

PLHmoveinalldirectionswhen AlthoughhopplantsaresusceptibletoPLH,theycantoleratesomeleveloffeedingandgrowersshouldbeconservativeintheapplicationofinsecticides

AtthistimethereisnoseteconomicthresholdforPLHinhops.

PLH

PLHManagement Themostcommonefficaciousinsecticidesrecommendedfor

thecontrolofpotatoleafhoppersincludethepyrethroidsandneonicitinoids

Pyrethroidsareeffectiveatcontrollingpotatoleafhoppersandremainrelativelyinexpensive,however,pyrethroidshavebeenshowntocauseincreasesinmite

Neonicitinoidsarelongerlastingandnarrowspectrummakingthemasolidchoiceformanagement

PyganicandTrilogyareOMRIapprovedinsecticidesorganicgrowersmightconsiderforPLHmanagement

Damsonhopaphid

Photos:compendiumofhopdiseasesandpests

Hopaphids overwinteraseggsonwildandcultivatedPrunus species MultiplegenerationsdeveloponPrunus host;canstay

onPrunus spp.throughoutthesummer,particularlyonthesuckergrowthofplums.

WingedfemalesproducedinMay;movetohopplants Givebirthtomanygenerationsofwinglessfemaleson

hops littlemovementwithinorbetweenhops InSeptember,femalesgivebirthtowingedfemalesand

malesthatreturnto Prunus. OnPrunus,thefemalesgivebirthtoegg layingfemales WingedmalesmatewiththemonPrunus. Fertilizedfemaleslayeggs;cyclestartsagain.

Hopaphids !Transmitseveralhopviruses hopmosaicvirus,Americanhoplatentvirus

Infestationsdevelopmorerapidlyduringcoolweather.

limitexcessivenitrogenapplicationfavorsaphidoutbreaks. Scoutingisrecommended2040leaves Provisionalthresholdnumbersare8to10aphidsperleaf

Aphidsshouldbecontrolledbeforeorduringfloweringtopreventthemfromenteringyoungcones.

aphidssecretehoneydewandcausecansootymoldtogrowinhopcones

Thresholdnumbersoftendeclinetozerowhenconesarepresent.

Enhancinghabitattoencouragebeneficialpredatoryinsectscanreducepopulationsofaphids.

Photo:SteveMiller,CornellHops Specialist

Insecticidesforhopaphids Malathion1B Baythroid (betacyfluthrin)3A Brigade(bifenthrin)3A Brigadier(bifenthrin/imidacloprid3A/4A)

Platinum(thiamethoxam)4A Provado (imidacloprid)4A Fulfill (pymetrozine) 9B Movento (spirotetramat)23

Insecticidesforhopaphids OMRIlisted Azadirect,(azadiractin)UN