乐果是一种对人畜毒性较低、残效期较短;同时具有触杀和内吸作用的有机磷杀虫药剂.它的杀虫范围很广,特别是防治各种蚜虫尤有特效.但是,如果使用不当,也会产生不良的后果,造成既浪费人力、物力,也对作物带来不应有的损失.特别是有些作物对其敏感性较强,浓度稍一偏高,就会发生药害.例如,有的地方用乐果防治梅花苗上的蚜虫,由于使用浓度过高而引起了药害,结果把它看作对梅花有天然的药害而不敢使用.乐果对梅花有否天然的药害?今年4月份,我们进行了试验. Dimethoate is a kind of organophosphorus insecticide with low toxicity to humans and animals, short residual period, and contact and endocytosis.Its insecticidal range is very wide, especially for the prevention and treatment of various aphids.However, If used improperly, it will also have adverse consequences, resulting in both waste of manpower and material resources as well as undue losses to the crops, especially if some crops are more sensitive to it and slightly higher in concentration will cause the medicine to take place For example, in some areas, dimethoate is used to control aphids on plum seedlings, causing phytotoxicity due to the high concentration used, and as a result, it is considered as a natural phytotoxicity to the plum and can not be used. Natural phytotoxicity? In April this year, we conducted a trial.