对于一次性收获的蔬菜如芹菜、甘蓝、大白菜等,可根据农药的安全间隔期,在收获前相隔一定的时间停止用药,以达到无公害生产的目的。但对于多次收获的茄果类和瓜类蔬菜来说,则很难做到在收获前规定出一定的时间停止用药,特别是在采收期内发生病虫害,果实很有可能未出农药残留期 For a one-time harvest of vegetables such as celery, cabbage, cabbage, etc., according to the safety interval of pesticides, at a certain time before harvest to stop medication, in order to achieve the purpose of pollution-free production. However, it is very hard for the eggplant and melon vegetables harvested several times to stop the medicine before the harvest, especially when the pests and diseases occur during the harvesting period, and the fruit is likely to have no pesticide residues period