麦田混生杂草生态经济阈值的研究

1999～2000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=0.0077x^1.6565。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

Studies on eco-economic thresholds of mixed-growing weeds in wheat fields

The damages and eco-economic thresholds of mixed-growing weeds, Capsella bursa-pastoris (L.) Medik, Descurainia sophia (L.) Webbn ex Prantl and Silene conoidea L. were studied on the practice farm of Shandong Agricultural University in 1999-2000. The results showed the effect of mixed-growing weeds in wheat yields was significant. The relation between wheat yield loss rate (y) and mixed-growing weed density (x) was simulated with the model: y=0.007 7 x 1 656 5 . Further studies indicated that weed density was significant to related spike number per 667 m 2 and every thousand kernel weight, but not to grain number per spike.