菵草与其它杂草的种间联结关系

Species Association between Beckmannia syzigachne( Stued.) Fernald and Other Weeds

采用Pearson点相关系数(Pointcorrelationcoefficient)方法,研究无除草剂使用历史的稻茬油菜田和冬闲地中 草[Beckmanniasyzigachne(Stued.)Fernald]与其它杂草种群之间的联结关系。结果表明, 草有较强的喜湿性,与看麦娘(AlopecurusacquallisSobol.)、牛繁缕[Malachiumaquaticum(L.)Fries]和雀舌草(StellariaalsineGrimm.)等杂草种群相比,在不用除草剂与正常耕作条件下, 草适应性与竞争力弱,难以成为杂草群落的优势种;但在冬季休闲的稻茬田中,由于受积水的影响,其发生量急剧上升。这是近年来 草危害性加剧的原因之一。

Method ofpointcorrelation coefficientwas used to study the speciesassociation between Beckman nia syzigachne ( Stued.) Fernald in rice rape double cropping field and winterfallow field withoutherbicideapplica tion and other weed population in this experiment.Compared with Alopecurus acpuallis Sobol.,Malachium aquaticum( L.) Fries and Stellaria alsine Grimm.,Bechmannia syzigachne( Stued.) had weaker adaptivity and com petitive ability withoutherbicide application undernormalcultivated condition,difficultto be dominantspecies.But as a hygrophilous weed planted in thewinterfallow field afterriceharvest,a greatnumberofitoccurred because of water accumulation.This was one ofthe reasons forthe increaseofharmfulnessof Beckmannia syzigachne( Stued.) Fernald.