农药混用的主要目的:一是防治两种或两种以上同时发生的病、虫、草害;二是提高药剂对病、虫、草害的防治效果,并防止病虫产生抗药性。农药混用时,大多数是效果互不干扰,仅起到兼治作用,如杀螟松与代森锌的混用;少数是能提高防治效果,如触杀型除草 The main purpose of pesticide mixing: First, prevention and treatment of two or more simultaneously occurring diseases, insects, grass damage; the second is to improve the agent on the disease, insects, grass and pest control effect and to prevent pest and disease resistance. When mixed with pesticides, most of the results do not interfere with each other, and only play a role in both treatment, such as fenitrothion and dexamethasone mixed; a few can improve the control effect, such as contact kill weeding