施农药先识药每种农药力有一定理化性质和防治对象，首先弄清了农药理化性质，认识了它，施药才有可能取得较好的防治效果。１．硫制剂对白粉病有特效，而对霜霉病类无效；铜制剂对霜霉病类有效，而对白粉病类无效。２．代森锌对锈病、晚疫病、炭疽病有特效，而对白粉病无... Pesticide pesticide knowledge of each pesticide have certain physical and chemical properties and control objects, first of all to understand the physical and chemical properties of pesticides, recognize it, the application of pesticides may achieve better control effect. 1. Sulfur formulations have a specific effect on powdery mildew and are not effective against downy mildew; copper is effective against downy mildew and powdery mildew. 2. Dezeen zinc on rust, late blight, anthrax have special effects, but no powdery mildew ...