一、目前国内外农田杂草危害及防除状况 1.国外情况: 世界上的杂草大约有3万多种,其中有1800多种对作物造成程度不同的损害;危害栽培作物的有200多种,其中危害较严重的有20～30种,这是农业生产上的防除对象。 40多年来,国际上的除草剂发展迅速,尤其自90年代以来,其年产量、销售与使用量都居领先地位。目前世界各国生产的除草剂品种已超过220多种,制剂达4000 First, the current domestic and foreign farmland weeds hazards and control status 1. Foreign situation: There are about more than 30,000 kinds of weeds in the world, of which more than 1,800 kinds of crops caused varying degrees of damage; endanger the cultivation of crops have more than 200 kinds , Of which 20 to 30 species are harmed more seriously, which is the object of prevention and control in agricultural production. For more than 40 years, the international herbicides have witnessed rapid development. In particular, their annual output, sales and usage have taken the lead since the 1990s. At present, more than 220 kinds of herbicides have been produced in all countries in the world and 4,000 have been formulated