苗期病害是水稻育苗期间多种生理性病害和侵染性病害的总称，也叫烂秧病。生理性烂秧是指不良环境条件造成的烂种、烂芽、黑根、青枯和黄枯死苗等症状；侵染性烂秧是指绵腐病和立枯病危害引起的死苗症状。北方稻区育苗期间常受低温和寒流天气袭击，烂秧病害每年均发病率在１０ Seedling disease is a general term for a variety of physiological diseases and infectious diseases during rice seedling raising, also called rotten seedling disease. Physiological rotten seedling refers to the bad environment caused by rotten seeds, rotten buds, black roots, yellowish brown and yellow dead seedlings and other symptoms; rotten seedling rot is caused by cotton rot and damping-off disease caused by dead seedling symptoms. Northern rice growing season is often affected by cold weather and cold weather attack, rotten seedling disease incidence in each year at 10