麦田阔叶杂草经济阈值及防除研究

作者对麦田阔叶杂草调查结果表明，麦田常发生阔叶杂草２０种，为害严重的８种，发生特点是前早、中缓、后快。作者选用高重积作为麦田阔叶杂草群落划分的标准。研究表明，阔叶杂草的各项生物指标经相关检验，以鲜重与小麦产量间关系密切。

STUDY ON THE ECONOMIC THRESHOLD AND CONTROL FOR BROADLEAF WEEDS IN WHEAT FIELD

In this paper, studies on broadleaf weeds in wheat field, showed that 20 breadleaf weeds, 8 of which were most serious, and often appeared in wheat fields. Their appearance characters were early at earlier stage, slow at middle stage and fast at later stage. Product of height multiplied by weight was used as a standard to classify community for broadleaf weeds in wheat fields. Examining the biological targets of broadleaf weeds, there was a closer relationship between the fresh weight and wheat field. By the SSR determination on the effect for broadleaf weeds to wheat field, the difference of 5 - 10 weeds was significant. The relationship among the density (plant/m2) fresh weight (g/m2) of broadleaf weeds and the loss rate of wheat field was striking linear relation. No. of plant Y = 3. 0418 1. 4314X (r = 0. 9993 * " , sum of squares for residual = 0. 3034). Fresh weight Y = l. 0445 0. 0366X(r = 0. 9931* ,sum of squares for residual = 3. 1275). Eco-economic threshold and its control threshold for the broadleaf weeds in wheat field was found out. According to the threshold, suggestions on economic control of broadleaf weeds was put forward.