KENYAACCELERATEDVALUECHAINDEVELOPMENTPROGRAM(AVCD)

ROOTCROPSCOMPONENTAPICALROOTEDCUTTINGSFORSEEDPOTATOPRODUCTION

PlantingandmanagingrootedpotatocuttingsRootedcuttingshavethepotentialtotransformpotatoseedsystems.Therapidandhighrateofmultiplicationwillsignificantlycontributetoreducingseedpotatoshortages.Eachcuttingproduces7to10tubers,andupto15+,which are multiplied a further season or two then the harvest is sold as seed. This is very high-quality seed,equivalent tobasicor certified seed in seedcertification systems.Thismeans that the seed that farmersbuy isextremely high quality andwill produce high yielding crops, encouraging seedmultipliers and farmers to keepcomingbacktobuymore.Anapicalrootedcuttingissimilartoanursery-grownseedling(Fig.1).Cuttingsareproducedfromtissuecultureplantsinascreenhouse,andarecleanandfreeofdisease.Cuttingsareplantedinthefieldinslightlyraisedbedstoproducehighnumbersofseedtubers.Wateringcuttingsuntiltheyareestablishedisessential.Startingwith500(10mx5m)to1,000(10mx10m)cuttingsisrecommended.Thisareacanbewateredwithawateringcan.LandpreparationCuttings areextremelyhighqualitymaterial coming from the screenhouse. Select a sitewherepotato, tomato,eggplant,peppersornightshadehavenotbeenplantedforatleast6seasons.Preparelandbymarkingthebeds.Eachbedis50cmwidewith50cmbetweenbeds.Digthesoil20-30cmunderthesoillineandmakearaisedbed3-5cmheight(Fig2&3).

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PLANTINGHILLING

Plantrootedcuttings3rowsperbed:20cmbetweenrowsand25cmbetweenplantsinarow(Fig.3).Planteachcuttingwiththestemline2-3cmbelowthesoilline,thismeanthatpartofthestemwillbeburiedabout3cm(Figs.1and2,redarrows).

CutwormsItisrecommendedtoalwaystreatthesoilforcutwormsattransplanting.Useinsecticidestocontrolcutwormsimmediatelyattransplantingandoneweeklater,orasrequired.Examples:a.i.thiamethoxam(Actara25WG,Medal25WDG, Engeo247SC)anda.i.alpha-cypermethrin(Bestox, TATAALPHA10EC).CuttingsneedwateruntilestablishedKeepcuttingswell-watereduntilwellestablished.Thismeanswateringtwiceadayrightafterplantingreducingtoonceadayuntilthecropisestablished.Yieldlosswillbesignificantifthecropisnotwellwatereduntilwellestablished.HillingWhentheplantis15cmhigh,hilltopartiallycovertheplant,5-10cm(Fig.2).CropManagementCareforthecropasyouwouldyourseedcropprovidinggoodfertilizerandmanagingdiseases(refertoseedpotatomultipliermanual).HarvestAs thecropmatures,checktubersize.Oncethemajorityof tubersareseedsize (eggsize),dehaulmthecropbycuttingdownall abovegroundplantmatter – separating theplant from the tubers.Be sure to removeall plantmatterfromthefield,leavingitlyingaroundcouldbringdiseasetothetubers.Forfollowingseasons,checktubersizeaftertheflowersdropanddehaulmasforseedcrop.Itisimportanttochecktubersizewhenproducingseedaftertheflowersdrop,assomevarietiesthetubersgetverybigveryfast,suchasUnica.RootedpotatocuttingsareeconomicalStartingwith1,000cuttingsatanapproximatecostof15,000KES,aseedmultiplierisprojectedtoproduce7650-kgbagsofseedpotatoaftertwoseasonsofmultiplications(oneyear).Planting1,000cuttingsrequires100m2forthe firstseason, then0.20ha (0.5acres) for thesecondseason.Comparedtominitubers,wherethesame initialarea of 100m2 is projected to produce 59 50-kg bags, profits from cuttings are 40% greater than those whenstartingwithminitubers.

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