一、流行原因 1.种子带菌:种子消毒不彻底,是导致苗瘟流行的直接原因。 2.土壤带菌:连年使用同一块地育苗,土壤中稻瘟病菌逐年增加,导致苗瘟大面积发生。 3.浇水过多:水稻旱育秧要求在缺少水层的情况下,培育强大的根系,以达到苗壮的目的。浇水过多易造成秧苗徒长、瘦弱、根系浅、抗病力下降。 First, the prevalence of reasons 1 seed carrier: seed disinfection is not complete, is the direct cause of the epidemic of seedling blast. 2. Soil-borne bacteria: year after year to use the same piece of nursery stock, rice blast bacteria increased year by year, resulting in large-scale occurrence of blast disease. 3. Too much watering: Rice dry seedlings require the cultivation of a strong root system in the absence of water, in order to achieve the goal of strong seedlings. Watering too easy to cause the growth of seedlings lean, emaciated, shallow root, decreased resistance to disease.