化学农药在杀灭病虫害中 ,若使用不当不仅影响防治效果 ,而且会产生药害。因此 ,在使用化学农药时务必注意以下几点 :1　掌握化学药剂性能与防治对象特点 ,对症下药。每种化学农药都有其一定的防治对象和使用范围 ,如杀螨灵、三氯杀螨醇主要作用是杀螨 ,对其它病虫害无效 ;又如 Chemical pesticides to kill pests and diseases, if used improperly not only affect the control effect, but also produce phytotoxicity. Therefore, the use of chemical pesticides be sure to pay attention to the following points: 1 master the performance of chemical agents and prevention and control of the object characteristics, the right medicine. Each chemical pesticide has its own control object and scope of use, such as miticide mites, dicofol the main role is to kill mites, other pests and diseases ineffective; Another example