Effect of seed size on germination,vigour, growth and yield in maize(ZeamaysL.) genotypes

LAWRENCE, M.RAVINDER RAJ, A.2018-06-042018-06-041997D5198http://krishikosh.egranth.ac.in/handle/1/5810048917A ﬁ eldexperimenttostudy“Effectofseedsizeongermination,vigour,growth and yieldinmaize(ZeamaysL.)genotypes”wasconductedattheAgriculturalCollege Farm Rajendranagar during rabi1995-96. Thelay outwasarandomizedblockdesignwith three replications.Therewereeighteentreatmentswhichincludedafactorialcombination of threemaizehybridsDHM 105, DHM 107 andDHM109with six seedsizegradesviz., 6.40,6.75,7.00,7.50and8.00mmsizeandunsortedseed. The results showedthat the vegetativegrowthofthethreemaizehybridswasnot influencedbythedifferentseedsizes.ThetwohybridsDHM107andDHM109ﬂowered earlierthanDHM105.Butnoneofthemshowedasigniﬁcantchangeinthedaysneededto flower initiation or 50percentsilkingduetodifferentseedsizes. Thelargesizeseedof8.00mmwassigniﬁcantlysuperiortotheunsortedseedof DHM105andDHM109inincreasingthelengthofthecobandtotalnumberofseedsper cob.SignificantimprovementincobgirthwasrecordedbylargesizeseedonlyinDHM 105.Thecobweightandthetestweightofthethreehybridswerenotinﬂuencedbythe seedsizegradation.Theseedyieldperplantduetounsortedseedwasonparwiththeyield duetodifferentgrades.Howeverthemeanseedyieldperplantwassigniﬁcantlylessfrom thecropsownwithundersizedseedof6.40thanthelargegradeof8.0mm. Theyieldperhectareduetotheunsorted seedofDHM105andDHM107was onparwiththeyieldduetolargeseedsizegradesof7.00,7.50and8.00mm.Theyielddue tounsortedseed(4850kgha“)ofDHM109wasalsoonparwiththeseedgradesof7.00 and7.50mmbutsignificantlylessthantheyieldrealised(5099kgha")fromthelarge gradeof8.0mm. Thequalityoftheunsortedseedintermsofgerminationpercent,rootandshoot lengthwasonparwiththelargestseedgradeof8.00mminthethreehybrids.Theseed obtainedfromthecropsownwithseedof6.40or6.75mmgradesinDHM107andDHM 109and6.40mminDHM 105hadsignificantlylowgerminationthanthosefromthe unsortedorthe8.00mmseedgrades.Thevigourindexoftheunsortedseedwasonpar withthelargestgradeof8.00mm.Therecoverypercentageoftheseedwith8.00mm gradewasonlyabout12%whilethosewith7.00mmandmoregradationwas98%.Itis inferredthatmaizeseedlotsofDHMIOS,DHM107andDHMIO9withmorethan250g testweightneednoseedsizegradationandminimisetheexpectedlossofpreciousseedfor furthersowing.ennullEffect of seed size on germination,vigour, growth and yield in maize(ZeamaysL.) genotypesThesis