夏玉米地杂草为害的产量损失模型

YIELD LOSS MODEL DUE TO THE INFESTATION OF WEEDS IN SUMMER MAIZE

为了明确杂草种类对杂草密度与夏玉米产量损失之间的函数关系的影响及反枝苋和马齿苋为害夏玉米的产量损失模型,在田间开展了此项研究。试验结果表明,反枝苋和马齿苋为害均不显著地影响夏玉米的籽粒重和单位面积穗数,造成夏玉米产量损失主要是通过降低每穗的籽粒数来实现的。杂草密度和夏玉米产量损失之间的函数关系因杂草种类不同而异,描述反枝苋密度和夏玉米产量损失之间的关系用双曲线优于S形曲线,而描述马齿苋密度和夏玉米产量损失之间的关系则用S形曲线优于双曲线。在北京地区,反枝苋和马齿苋密度(X)与夏玉米产量损失(Y_L)的模型分别为:Y_L=0.49X/(1+0.49X/58.73)和Y_L=18.36/(1+1601.83X^(-1.6))

A field experiment was conducted to determine the relationships between the yield loss of summer maize and the infestations of Amaranthus retroflexus and PoHulaca oleracea. The results showed that the weed damage did not significantly affect grain weight and ear number of summer maize. The crop yield was mainly determined by kernel numbers per ear under the condition of the weed infestation. The relationships between crop yield loss and weed infestation depended on weed species. The relationship between summer maize yield loss and A. retroflexus density was hyperbolic, while that between the crop yield loss and P. oleracea density was S-shape.