一、什么是农作物病害农作物在生长发育过程中,由于环境条件不适宜或遭受其他寄生物的侵害,引致生长发育不良,甚至因病死亡,使产量下降或品质变坏,这种现象概称农作物病害。农作物生病后出现的不正常变化称为病害的症状。其可分两大类:一类是作物本身出现的不正常状态弥为病状,如斑点、腐烂、萎凋、退色、变色、枯落、矮缩、畸形、枯萎等;另一类是寄生在作物上的病原生物的特殊表现叫做病征,如白粉、霜霉、黄疸、黑疸、菌核等。多数病害都是根据它的特有症状命名的,如水稻自叶枯病、纹枯病,小麦白粉病、锈病等。 First, what is the crop disease Crops in the process of growth and development, due to environmental conditions inappropriate or suffer from other parasites, resulting in poor growth and development, or even death due to disease, so that the yield decline or deterioration of quality, the phenomenon of agricultural crops Diseases. The abnormal changes that occur after a crop is sick are called symptoms of the disease. It can be divided into two categories: one is the crop itself is not the status of Mi is pathological, such as spots, decay, wither, fade, discoloration, litter, dwarfing, deformity, wilt; the other is parasitic on crops Pathogens on the special performance is called symptoms, such as white powder, downy mildew, jaundice, jaundice, sclerotia and so on. Most diseases are named according to its unique symptoms, such as rice blight, sheath blight, wheat powdery mildew, rust and so on.