发展化学除草重视综合治理

我国农田杂草有２５０多种，全国农田受草害面积４３００多万ｈｍ２，平均受草害减产１３．４％，每年减产粮食１７５０万ｔ，皮棉２５．５万ｔ和大豆５０万ｔ。传统农业生产采用机械作业及人力等除草。随着农村经济的发展，化学除草面积迅速扩大，全国农田化学除草面积从１９７５年的１７０万ｈｍ２增加到１９９５年的４１３３万ｈｍ２。但是，长期化学除草也带来了除草剂土壤残留对后茬作物药害、农田杂草种群更替和产生抗药性等新问题。必须重视农田杂草综合治理，通过采用各种有效的农业技术措施，为农作物保持良好的生态条件，结合化学除草才是最有效的防除杂草方法

DEVFLOPING CHEMICAL WEED CONTROL AND ATTACHING IMPORTANCE TO INTEGRATED WEED MANAGEMENT

About 250 species of weeds have been determined as the field weeds in China. It is estimated that more than 43 million hectares of the main crop fields are heavily infested with weeds, and the average reduction of crop yield caused by weeds is estimated at 13.4%. About 17.5 million tons of grains, 255 thousand tons of lint cotton and 500 thousand tons of soybeans were lost by the most harmful weeds annually. Conventional weed control measures, such as mechanical weed control and hand pulling. Along with rural economic development, chemical weed control becomes more important and attractive to farming people. The herbicide application area was steadily enlarged from 1.7 million hectares in 1975 up to 41.33 million hectares in 1995. Meanwhile, continuous use of the herbicides on crops for a number of years caused residual phytotoxicity on crops, weed shift problem and resistant weed development. It must pay attention to integrated weed management. Elimination of weeds from crop fields through adopting various effective agricultural measures and keeping favorable ecological conditions integrated with chemical weed control is a most effective measure.