玉米各个生育时期地道英文表达方式

GrainCropsExtension,UniversityofKentuckyCornGrowthStagesChadLee,Ph.D.GrainCropsExtensionSpecialistUniversityofKentuckyGrainCropsExtension,UniversityofKentuckyHowaCornPlantDevelops,SpecialReportNo.48IowaStateUniversityPress$2.00ExtensionDistributionCenter119PrintingandPublicationsBuildingIowaStateUniversityAmes,Iowa50011-3171Telephone:[phone]Fax:[phone]…GrainCropsExtension,UniversityofKentucky(n)nthleafR5dentVTtasselingR6physiologicalmaturity*Whenstagingafieldofcorn,eachspecificVorRstageisdefinedonlywhen50percentormoreoftheplantsinthefieldareinorbeyondthatstage.:Splittheentirestalk(fromthetiptotheroots)inhalfwithaknife.Thefirstfivenodeswillbeclusterednearthebottomofthestalkandthe6thnodewillbeveryclosetothesoilline.Countnodesabovethe6thnodetodeterminehowmanynodesarepresent.ThetotalnumberofnodesequalstheV-stageoftheplant.Forexample7nodes=V7corn.V6:Typicallywhenlowerleavesbegintotearoffofstalk.GrainCropsExtension,UniversityofKentuckyV6NodalRootSystemistheprimaryrootsystemfornutrientsandwater.Growingpointisabovetheground.Earshoot.GrainCropsExtension,UniversityofKentuckyV6PrematureTasselGrainCropsExtension,UniversityofKentuckyV9GrainCropsExtension,UniversityofKentuckyV9Growthraterapidlyincreases.Greaterdemandfornutrientsandwater.Earshoot.Earshoot.Earshoot.Growingpoint.GrainCropsExtension,UniversityofKentuckyV12Bothkernelsizeandkernelnumberarebeingdetermined.Anylimitsonwaterornutrientsatthisphasewilldrasticallyimpactyields.Earliermaturinghybridswillpassthroughthisphasefasterthanlatermaturinghybrids.GrainCropsExtension,UniversityofKentuckyV15About10-12daysfromsilking.Enteringthemostcriticalstageforyielddetermination.Theplantismostsensitivetowaterand/ornutrientstressatthisstage.Irrigation-the4weeksaroundsilkingarethemostcritical.GrainCropsExtension,UniversityofKentuckyV15Earshootsnearthetopoftheplantarestartingtoout-growearshootslowerontheplant.LowerpartofplantUpperpartofplantGrainCropsExtension,UniversityofKentuckyV18GrainCropsExtension,UniversityofKentuckyV18LowerpartofplantUpperpartofplantGrainCropsExtension,UniversityofKentuckyV18LowerpartofplantUpperpartofplantGrainCropsExtension,UniversityofKentuckyVT-TassleOccurswhenlastbranchoftasselisvisiblebutbeforesilksemerge.Mostsusceptibletohaildamageatthisstage.CompleteleaflossatVTwillresultinlittletonoyield.GrainCropsExtension,UniversityofKentuckyVTGrainCropsExtension,UniversityofKentuckyPollenshedGrainCropsExtension,UniversityofKentuckyR1-SilkingSilksstartingtoemerge.Nuptakeisrapid.Puptakeisrapid.Kuptakeisnearlycomplete.Watchforcornborerfeeding.Moistureisneededforpollination.GrainCropsExtension,UniversityofKentuckyR1-SilkingCobmaterialPrematurekernelTwotothreedaysarerequiredforallsilksonaneartobepollinated.GrainCropsExtension,UniversityofKentuckyR2-BlisterAnminiaturecornplanthasstartedtodevelopwithintheprematurekernel.Earsizeisnearlycomplete.Fertilizedsilksarestartingtodryout.GrainCropsExtension,UniversityofKentuckyR3-MilkKernelsarebecomingyellowontheoutside.Silksaredry.Kernelsareat80%moisture.Stressbecomeslessofafactoraskernelsstarttodrydown.GrainCropsExtension,UniversityofKentuckyR4-DoughFluidinthekernelisbecomingaconsistencysimilartodough.(70%moisture)Almost½ofthedryweighthasbeenaccumulated.Fiveembryonicleaveshaveformedinthekernel.Thesewillbethefirstfiveleavesofanewplantasitemergesnextyear.GrainCropsExtension,UniversityofKentuckyR5-DentMostofthekernelshavedentedonthetop.Mostkernelsareabout55%moistureatthestartofR5.Astarchlayerhasformedandbeginstoprogressdownthekernel.Afrostwillstopdrymatteraccumulationandreduceyields.GrainCropsExtension,UniversityofKentuckyR6–PhysiologicalMaturityBlacklayerGrainCropsExtension,UniversityofKentuckyR6–PhysiologicalMaturityKernelisabout30–35%moisture.Kernelsneedtobeat13to15%moistureforsafestorage.GrainCropsExtension,UniversityofKentuckyVegetativeStagesReproductiveStagesVEemergenceR1silkingV1firstleafR2blisterV2secondleafR3milkV3thirdleafR4doughV(n)nthleafR5dentV