增施除草剂条件下大豆和三裂叶豚草生长竞争的变化分析

应用生态学中竞争的理论,探讨增施除草剂条件下大豆和三裂叶豚草生长的变化情况.采用裂区设计,主区为除草剂处理,副区为三裂叶豚草密度处理.三裂叶豚草密度设0,8,32,48株·m~(-2)共4个处理,分别用D0、D1、D2、D3表示,各处理设3个重复.结果表明:大豆株高在结英期施除草剂条件下,处理D0最大,达103.49cm,与未施除草剂下差异不显著;大豆生物量的表现为大豆茎重在开花期和结英期随着三裂叶豚草密度的增加而降低,大豆地下部分生物量,除开化期施除草剂的处理外,均随着三裂叶豚草密度的增加而呈先增加后减少的趋势.三裂叶豚草株高和分枝数在各个生长时期均受到除草剂和自身密度的共同作用,各个时期施除草剂条件下株高和分枝数均显著低于未施除草剂条件.三裂叶豚草叶重与茎重变化规律相同,都随着三裂叶豚草密度的增加而降低.研究表明,除草剂能显著抑制三裂叶豚草的生长,大豆的生长受来自种内和种间竞争的共同影响.

Competition between Soybean and Ambrosia trifita L. in Different Herbicide Levels

With the use of competition theory of ecology, the growth of soybean and Ambrosia trifida was studied.Split-plot was used with the main plot of herbicide treatment and subplot of Ambrosia trifida density.There were four treatments with three replications of density(0,8,32,48 plants /m~2, expressed as D0, D1, D2, D3). The results showed that in podding stage DO soybean plant height was 103.49cm, height among all treatments. Soybean stem weight in flowering and podding stages decreases with the increase of Ambrosia trifida density. With the exception of herbicide application at flowering stage, the biomasses of underground parts of soybean increased first and then decreased with the increase of Ambrosia trifida density. Ambrosia trifita plant height and branches in each growth period were subject to the density and herbicides. The plant height and number of branches decreased under herbicide application. The leaf height was affected like the stem weight, it was concluded that herbicide can notably control the growth of Ambrosia trifida and that the growth of soybean is effected through interspecific and intraspecific competition