世界人口的近期增长及其对自然资源产生的压力,目前正影响着杂草防除的经济状况,对将来也将产生深远的影响。杂草在作物中造成的各种损失由于杂草的存在而造成的作物损失是严重的,虽然其损害不象其它害物所造成的损失那样一目了然。这些损失发生在作物生长周期的各个阶段。杂草①使作物减产;②影响作物质 The recent growth of the world population and its pressure on natural resources are now affecting the economic status of weed control and will have far-reaching implications for the future. Weeds damage caused by crops Crop losses caused by the presence of weeds are serious, although their damage is not as visible at the expense of other pests. These losses occur at all stages of the crop’s growth cycle. Weeds (1) to reduce the crop; (2) affect the crop