近年来 ,随着种植结构的调整、耕作制度的改革 ,大面积使用化学除草剂 ,农田杂草优势种群和群落结构相应发生了变化。为掌握本市棉田杂草种群结构和发生危害情况 ,为今后治理草害提供依据 ,合理使用除草剂、及时控制其危害 ,笔者于1 999年 7～ 8月所辖潍城、奎文、寒亭、坊子 4 In recent years, along with the adjustment of planting structure, the reform of farming system, large-scale use of chemical herbicides, the dominant population of farmland weeds and the community structure have changed correspondingly. In order to grasp the weed population structure and the occurrence of harm in our cotton field, provide the basis for the future control of weeds, use herbicides reasonably and control their harm in time, the author in July 1999 to July under the jurisdiction of Weicheng, Kuiwen, cold Pavilion, Square 4