Zantedeschia aethiopica
ArumLiliesareawidespreadconspicuousplantprimarilyfoundinwet,swampyhabitats These lilieswereoriginallyintroducedfromSouthAfricaforhorticulturepurposes ArumLiliesare DeclaredPlantsinWesternAustraliaandallmovementisprohibited
The Problem / Impact
ArumLilyistheworstenvironmentalweedintheCapesregion.Itoccursinbothpasture, plantationandbushland,particularlyindampareasbutalsoinvadingdriersites.Arumlilyis spreadbybirdsandthedisturbanceofrhizomes(justthesmallestpieceofrhizomecancreatea newplant)andinvadesareasofgoodqualitynativevegetation.
TheimpactsofArumLilyinclude:
Formingofdensemonocultures&outcompetingnativespecies,reducingbiodiversityand decreasinghabitatandfoodresourcesfornativeanimals.
Arumlilyispoisonoustomoststock,petsandhumans.Symptomscanincludeswellingofthe tongueandthroat,stomachpain,vomitingandseverediarrhoea.Ingestionoftheplantmaybe fatal.
ArumlilyislistedasaDeclaredPlantundertheBiosecurityand AgricultureManagementAct2007.UndertheActlandholdersare requiredtomanagearumlilytoreducethesizeofinfestationsand preventthespreadoftheweed.Sightingscanbereportedonthe MyWeedWatcheronline/smartphoneapp:www.agric.wa.gov.au/n/5412
Growth Habit & Biological Weak Link
ArumLilyisa rhizomatous(tuber-like)perennialto1m highthatformsdenseclumpsofdistinctive largegreen leavesandtrumpetlikewhiteflowers.
Itspreferredhabitatinthesouthwestiswetlands,along rivers,streamsorcreeks,wetareas,low-lyingpastures, undertreeswherebirdsperch,indunesandcoastal heath,andgardens.
ArumLily’sbiologicalweaklinkiswhenitisactivelygrowingfromJunethroughtoNovember, withtheoptimumtimeforcontrolwhenatleast50to70%offlowersarepresent(Julyto October)oruntiltheflowersstarttowither.
Management & Control Options
Plantsproducelargeamountsofseedtowardstheendofthefloweringseason.Theseedsare heldwithinsucculentberriesandbirdsarethemainvectorsofdispersal.Aswellas reproducingviaseed,ArumLilyreproducesvegetativelyviasmallrhizomesproducedonthe sidesofthemaintuber.A2cmtubercanproduce25-30smallrhizomesinayear.
Yourcontrolplanmusttakeintoaccountbothformsofreproduction–plantsgrowingfrom survivingdaughterrhizomesarenotusuallyvisibleuntiltwoyearsaftertheinitialsprayingso thelikelihoodofreinfestationfromsurroundingareaswillnecessitateanon-goingprogramof control.
CHEMICALCONTROL:
What?Useamixtureof1gmofchlorsulfuronormetsulfuronper10Lwater.Awettingagent ordetergentshouldbeaddedtoimprovetheperformanceofthechemical.Apenetrantsuchas Pulsecanbeusedtoimproveeffectiveness,particularlyonolder,wellestablishedplants.
How?Sprayleavestothepointofrunoff Off-targetspeciescanalsobekilledsoitisimportant toapplytheherbicidecarefullytothearumlilyleavesonly PleasenotethatChlorsulfuronand metsulfuronareveryslowactingchemicals Youmaynotseetheresultofthechemicalfor upto2months
PHYSICALCONTROL:
Handremovaloftheplantisonlyeffectiveifthetuberousrhizomeanddaughterrhizomesare removed Theresultingsoildisturbancemayencouragegerminationandestablishmentofother weeds Removalofflowerswillpreventbirdsspreadingseeds
Rehabilitation & Prevention
Wherearumlilyoccurssparselyorisolatedpatchesingoodqualitynativevegetation,thegap createdbyremovalissmallandquicklycolonisedbynativespecies However,wherearumlily growsasadensemonocultureremovalwillleaveanareasusceptibletoinvasionbyother weeds Controloftheseweedsmayhelpfacilitateestablishmentofnativeplants Consideration shouldalsobegiventodirectseedingorrevegetationwithlocalnativespecies
References & Further Information
SourcesofInformationforthisflier:
AGuidetoArumLilyControl–NatureConservation
DPIRDWebsite:https://www.agric.wa.gov.au/declared-plants/arum-lily-declared-pest
FurtherReading:
Moore,J&Wheeler,J(2019)SouthernWeedsandtheircontrol.DepartmentofAgricultureandFood WA.
HerbiGuidewww.herbiguide.com.au
Brown,K&Brooks,K(2002)BushlandWeeds,Apracticalguidetotheirmanagement.Environmental WeedsActionNetwork
LowerBlackwoodLCDC 403KudardupRoad,KudardupWA6288 POBox42,KarridaleWA6288
T:97584021| E: info@lowerblackwood.com.au wwwlowerblackwoodcomau
This booklet was funded through the State NRM Community Stewardship Grants 2019