Sustainable Management of Soil-borne Diseases in Nursery ... · Sustainable Management of Soil-borne Diseases in Nursery Production SARE PROJECT GS16-155 Baysal-Gurel Fulya Baysal-Gurel

.Appl.21:379-380.

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Introduction§  Soil-bornediseasesareamajorconstraintinwoodyornamentalnurseryproduction.§  Soil-bornepathogenshavebeenconventionallycontrolledbyperformingsoilfumigationusingmethylbromide,whichwascompletelyphasedoutfromthemarketofdevelopedcountriesby2005.

§  Findinganeffectivealternativeformethylbromideisanhighpriorityinagriculturesector.§  In agriculture, plants containing Glucosinolates (GSL) have a long history of use as rotation crops, greenmanuresorasseedmealsoilamendmentstothesoilduetoitsbiocidalproperties.

§  CovercropsinthefamilyBrassicaceaehavetheabilitytosuppresssoilmicroorganismsthroughthehydrolysisofGSLintoisothiocyanate,anaturalbiofumigant.

§  MostofthestudieshavebeenconductedonGSL-relatedsuppressionandtheyshowsigniPicantabilitytocontrolsoil-bornepathogens

§  Useofbiofumigationinwoodyornamentalnurseryproductionhavenotbeendocumentedsofar.

ObjectiveThe objective of this studywas to assessBrassicaceae cover crops as biofumigant for soil-bornediseasemanagementinnurseryproduction.

MaterialsandMethods§  FifteenBrassicaceaecovercropswereselectedatthebeginningofthestudy(Figure1).§  SterilizedtopsoilwasinoculatedwithRhizoctoniasolaniandPhytophthoranicotianaeand10covercropseedsweresownineachpottoevaluaterootrotdiseaseseverityandincidenceafter1month.

§  Selectedcovercropswereusedtoperformbiofumigationingreenhousestudies.Hydrangeaandviburnumplantsgrowninbiofumigatedsoil(14-and30-days)andplantrootswereevaluatedfordiseasesymptoms.

§  CovercropsthatshowedhighestdiseasesuppressionabilitywereselectedforthePieldstudyatacollaborator’snurserywithprevalentR.solanipressure.Biofumigationwasperformedfor14-dayswithastroarugula,amaramustardandpurpletopforageturnips.Mustardmealandcompostwasalsotestedinthisexperiment.

§  Floweringcherrycuttingswereplantedtwoweeksafterbiofumigation.Plantheightandweightweremeasuredandrootrotdiseaseseveritywasdeterminedattheendofthetrial.

0 10 20 30 40 50 60 70 80 90 100

AmaramustardgreenDwarfessexrapeOrientalmustard

AstroarugulaPurpletopforage

MustardMightymustard®

OilseedradishSylvettagreenarugula

Dragon'stongueRedgiantmustard

ArugulaWasabiarugula

Olive-leavedsylvettaBelleziaarugula

Rootrotdiseaseseverity(%)

P.nicotianae

R.solani

SustainableManagementofSoil-borneDiseasesinNurseryProduction

FulyaBaysal-GurelandPrabhaLiyanathianage*SAREPROJECTGS16-155Baysal-Gurel

ThisprojectissupportedbytheNationalInstituteofFoodandAgriculture,U.S.DepartmentofAgriculture,underawardnumberGS16-155Baysal-GurelthroughtheSouthernSustainableAgricultureResearchandEducationprogramundersubawardnumberRD309-134/S001230.Anyopinions,Pindings,conclusions,orrecommendationsexpressedinthispublicationarethoseoftheauthor(s)anddonotnecessarilyrePlecttheviewoftheU.S.DepartmentofAgricultureorSARE.USDAisanequalopportunityemployerandserviceprovider.

Covercropusedforbiofumiga2on

ViburnumsuspensumRhizoctoniarootrotseverity

(%)

HydrangeapaniculataPhytophthorarootrotseverity

(%)

Biofumiga4on(14-days)

Biofumiga4on(30-days)

Biofumiga4on(14-days)

Biofumiga4on(30-days)

Amaramustard 19.3de 15.1ef 23.4d 23.4cAstroarugula 23.4cd 27.6cde 23.4d 15.1cdMightymustard 23.4cd 19.3e 31.8bcd 27.6cMustard 35.9b 35.9cd 31.8bcd 23.4cOrientalmustard 40.1b 40.1bc 40.1bc 23.2cRadish 44.3b 52.6b 44.3b 56.8abRape 40.1b 35.9cd 27.6cd 15.1cdPurpletopforageturnips 31.8bcd 23.4de 35.9bcd 48.4b

Non-inoculatedcontrol 6.8e 4.5f 2.3e 8.7dInoculatedcontrol 77.6a 73.4a 65.1a 69.3aP-value 0.00 0.00 0.00 0.00

Table1.RhizoctoniarootrotdiseaseseverityofviburnumandPhytophthorarootrotdiseaseseverityofhydrangeaplantsafter14daysor1monthbiofumigation(Greenhousestudy)

Treatment Rootrot(%)

Plantheight

Plantwidth

Rootweight

Amaramustard 33.7b 22.7ab 18.6b 7.3b

Astroarugula 34.4b 21.5bc 18.2b 7.0b

Turnips 38.8b 21.0bc 18.8b 6.3b

Mustardmeal 49.4ab 21.7abc 21.9b 7.3b

Compost 49.7ab 26.4a 27.2a 10.7a

Non-treatedcontrol 63.2a 17.8c 18.2b 6.3b

P-value 0.02 0.04 0.00 0.01

Table2.Effectsofsoilamendmentsandbiofumigantcovercropusageoncrophealth(On-farmstudy)

ResultsandDiscussion§  Oilseed radish,mustard (Sinapis alba), purple top forage turnip, astro arugula,mightymustard®paciPic gold,orientalmustard,dwarfessex rapebrassicaandamaramustardgreenshowed lower root rotdisease severitypercentages and disease incidence percentages (data not shown) compared to the other tested cover crops(Figure1and2).

§  Whenbiofumigationwasperformedfor14-and30-daysastwogreenhousetrials,similardiseaseseverityvalueswererecordedbytheplantsgrowninBrassicaceaecovercropsincorporatedpots(Table1).

§  Plants grown in amara mustard, astro arugula and purple top forage turnips incorporated soil resulted lessPhytophthoraandRhizoctoniarootrot.

§  Amaramustard,astroarugulaandpurpletopforageturnipswereeffective incontrollingsoil-bornepathogenscomparedtocompostandmustardmealamendmentsunderPieldcondition(Table2).

§  Amaramustard,astroarugulaandpurpletopforageturnipsbiofumigantcovercropsshowedpromisingresultsincontrollingsoil-bornepathogensofwoodyornamentalplantsunderbothgreenhouseandVieldconditions.

Seeding Covercropgrowthafter7days

Biofumigation

IncorporationBedpreparation

‘Kwanzan’cuttingstakenfromthemotherplants

8-10’’Cuttingswithslantcut

Cuttingsdippedin1%3-Indolebutyricacid(IBA)

Cuttingstransplantedintoeachplot

Covercropgrowthafter2months

Figure1.RootrotdiseaseseverityoftestedBrassicaceaecovercropswheninoculatedwithR.solaniandP.nicotianae

(b)

(d) (c)

(a)

Figure2.BrassicaceaecovercropsshowingdiseasesymptomsduetoR.solaniinfection.a)chlorosis,b)post-emergencedamping-off,c)plantdeath,d)pre-emergencedamping-off.

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