棉田覆膜后,杂草比裸地棉田提早7～10天出苗,20天左右即可达到生长盛期。影响了覆膜效果和棉苗的生长发育。为了清除棉田杂草,选择适宜的化学除草剂,必须摸清棉田杂草的种类和生长发育规律,根据朝阳县木头城子乡万亩棉田的调查结果,棉田杂草有15科,25种。其中单子叶杂草有马唐、毛马唐、虎尾草、稗草、狗尾草等5 Cotton fields, the weeds than the bare cotton fields 7 to 10 days earlier emergence, about 20 days to reach the peak growth. Affect the film effect and cotton seedling growth and development. In order to remove weeds in cotton fields and select suitable chemical herbicides, we must find out the types of weeds in cotton fields and the law of growth and development. According to the survey results of 10,000 mu of cotton in Chengzi Township, Chaoyang County, there are 15 families and 25 species of weeds in cotton fields. One of the monocotyledonous weeds are crabgrass, crabgrass, chloris, barnyard grass, green foxtail 5