二甲四氯是内吸型选择性除草剂,它能破坏植物体内新陈代谢,扰乱细胞的正常分裂,使植物失去正常的生活能力。但不同浓度有不同的作用,高浓度能抑制植物生长并出现畸形直至死亡。另外,不同植物对二甲四氯的敏感性、耐药性有差异,表现高度的选择性。一般阔叶植物最敏感,单子叶植物和禾本科作物五叶期后的分蘖期,耐药性较强。因此选择适宜浓度和时期施用,既能防除稻田杂草,如三棱 MCPA is a selective endothermic herbicide, which can damage plant metabolism, disrupt the normal cell division, so that plants lose their normal ability to live. But different concentrations have different effects, high concentration can inhibit plant growth and deformity until death. In addition, the sensitivity of different plants to MCPA, drug resistance differences, showing a high degree of selectivity. The most sensitive broad-leaved plants, monocotyledons and grasses at the tillering stage, strong resistance. Therefore, the choice of appropriate concentration and period of application, both to control rice weeds, such as triangular