摘要
以棉田优势种杂草马唐为对象，研究麦套棉移栽后有（无）草期长短与棉花产量及其构成因子的关系。结果表明，随着棉花移栽后有草期的延长和无草期的缩短，棉花产量逐渐下降，栽后在先有草而后无草的条件下，有草天数Ｘ（ｄ）与公顷产量Ｙ（ｋｇ）呈极显著非线性关系，Ｙ－１＝６．１８×１０－４＋３．４６×１０－６Ｘ；栽后先无草而后有草的条件下，无草天数Ｘ（ｄ）与公顷产量Ｙ（ｋｇ）呈极显著线性关系，Ｙ＝９７６．０５＋７．１０Ｘ。马唐对棉花的干扰危害期是栽后３０～９０ｄ，竞争临界期或防除关键期是栽后３０～６０ｄ，分别约占生育期的１／２和１／４。因此，生产上用土壤处理除草剂防除棉田杂草时，其有效期必须接近６０ｄ，用灭生性处理剂进行行间喷雾时，必须在移栽３０ｄ以后及时进行。
FieldexperimentwasconductedinNantongin1997tostudytheinfluenceofcrabgrassinfestedperiodontheyieldoftransplantedcottoninterplantingwithwheat.Crabgrass(Digitariasangunalis)isthedominantweedspeciesincottonfieldinJiangsuProvince.Accordingtotheresultofthetest,cottonyielddecreasedwiththeextensionofweedinfestedperiodandwiththeshorteningofweedfreeperiod.Whentherewasweedyaftercottontransplantationforafewdaysandartificiallyweededafterwords,therelationshipbetweencottonyieldandweedinfestedperiodwassignificantlydescribedbythenonlinermodelY-1=61810-4+34610-6X.Whentherewasweedfreeartificiallyaftercottontransplantationforsomedaysandwasweedinfestedafterwords,therelationshipbetweencottonyieldandweedfreeperiodwassignificantlysubjectedtothelinermodelY=97605+710XIntheaboveequations Ywaslintcottonyield(kg/hm2)andXrepresentedweedinfestedperiod(d)andweedfreeperiod(d)repectively.Theperiodofweedinterferenceanddamageandthecriticaltimeofweedcompetitionwithcottonwere3090daysand3060daysaftertransplantationrespectively,whichoccup
出处
《江苏农业学报》
CSCD
北大核心
1999年第2期87-91,共5页
Jiangsu Journal of Agricultural Sciences
基金
江苏省"九五"农业重大攻关课题
关键词
马唐
棉花
竞争临界期
麦套棉
移植
杂草
crabgrass
cotton
criticalperiodofcompetitionied 1/2and1/4ofthewholegrowingperiodofcotton.Sotocontroltheweedincottonfieldsuccessfullywithpreemergenceherbicide,theeffectiveperiodmustbenear60days
tocontroltheweedwithburndownherbicidebeingsprayedamongrows,t
