Effects of varying seed proportions and harvesting stages on biological compatibility and forage yield of oats (Avena sativa L.) and vetch (Vicia villosa R.) mixtures

摘要

Thestudyontheeffectofseedratesandharvestingstagesonforageyieldandqualityofoats(AvenasativaL.,accessionCI-8237)andvetch(ViciavillosaR.)mixtureswerecarriedoutduring2003croppingseasonatAdetAgriculturalResearchCenter,NorthwesternEthiopia.Theobjectivesofthestudyweretoassesstheoptimumseedingratesandharvestingstagesformaximumbiomassyieldandthebiologicalpotentialsoftheoats/vetchcomponentsinmixturesandpurestands.Theexperimentaldesignemployedwasasplitplotdesignwiththreestagesofharvesting,namely,flagleafstage(HS1),milkstage(HS2),anddoughstage(HS3)asmainplottreatments,andfiveseedproportionsofoats/vetch,namely,100:0(SP1),75:25(SP2),50:50(SP3),27:75(SP4),0:100(SP5)assubplottreatmentsinthreereplications.Thehighestherbagedrymatteryield(DMY)of13.22t/hawasrecordedatHS3andSP2.Significantlyhigherleaves/plant(5.15)foroatswasobtainedatHS2,whereashighestbranches/plant(15.27)forvetcheswasobtainedatHS3andSP5.Seedproportionfourforoatswasfoundtohavesignificantlyhigher(P0.01)leaftostemratiothantheotherSPs.RelativeyieldtotalwasfoundtobemorethanoneatHS2andHS3,withthehighestvalueof1.32atHS2andSP4,indicatingayieldadvantageof32%foroats/vetchintercroppingcomparedtosolecroppingofeitherofthetwoforagespecies.Therefore,itisconcludedthatcultivationofoats/vetchmixturewithseedproportionsof25%oatsand75%vetchandharvestingatmilkstageoffersbetterrelativeyieldadvantageofthemixtureandhigherleavesperplantandleaftostemratioforoats.