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1999～ 2 0 0 0年于山东农业大学实习农场对小麦田的荠菜、播娘蒿、麦瓶草等主要杂草混合生长的危害及生态经济防除阈值进行了研究 ,得出如下结论 :麦田主要杂草持续生长对小麦产量有显著影响 ;小麦产量损失率 (y)与杂草密度 (x)之间呈幂函数关系 ,即y =0 0 0 77x1 6565。随着杂草密度的提高 ,单位面积小麦穗数和千粒重明显降低 ,穗粒数则无显著差异
From 1999 to 2000, the hazards of mixed growth of main weeds such as Capselae, Artemisia selengensis and Betula platyphylla and their ecological and economic control threshold were studied in the internship farm of Shandong Agricultural University. The main conclusions are as follows: The continuous weed growth had a significant effect on the yield of wheat; the yield loss rate (y) of wheat and the weed density (x) showed a power function relationship, that is y = 0 0 0 77x1 6565. With the increase of weed density, the number of spikes and 1000-grain weight per unit area of wheat decreased significantly, but there was no significant difference