2,4-滴类除草剂具有很强的内吸传导性和选择性,一般用于禾本科作物分蘖期喷雾处理防治阔叶杂草及莎草。宽叶作物如大豆等对这类药剂没有生理上的抗药性,极为敏感,因此不能作生长期处理。但苗前土壤处理情况有很大的不同。由于大豆播种较深,出苗时种皮包裹子叶顶土(起到保护作用),所以种子及幼苗得以避免接触药剂。而杂草,包括禾本科杂草在芽期对这类药剂是敏感的,其芽和根着药后即逐渐死亡或受抑制。无产阶级文化大革命以来,广大兵团战士破除迷信,解放思想,大搞群众性科学实验活动,取得了用 2,4-D-type herbicides with strong internal absorption conductivity and selectivity, generally used for gramineous crops spraying tillering stage control weeds and sedge. Broad leaf crops, such as soybeans, are not physiologically resistant to such agents and are extremely sensitive and therefore can not be treated as growing ones. But before the seedling soil treatment situation is very different. Due to the deep seeding of soybean, the seed coat covers the top of the cotyledon at seedling emergence, thus protecting seed and seedlings from contact with the agent. Weeds, including grass weeds, are sensitive to such agents at the bud stage, and their buds and roots gradually die or are inhibited after they have been medicated. Since the Great Proletarian Cultural Revolution, the vast majority of Corps fighters have got rid of superstition, emancipated their minds and vigorously conducted mass scientific experiments,