水稻白叶枯病是一种检疫性病害。近几年来,上海郊区发生的面积和为害程度都有发展,发病田块,水稻千粒重显著降低,空秕率上升,青米、碎米率增加。一般轻病田减产10～20％,重病田在50％以上,严重的病田几乎颗粒无收。 Rice bacterial blight is a quarantine disease. In recent years, both the area and degree of harm in the suburbs of Shanghai have been developing. The incidence of paddy fields, the grain weight of rice has been significantly reduced, the rate of empty rice has risen, and the rates of green rice and broken rice have increased. General mild disease reduction of 10 to 20%, severe disease in more than 50% of serious disease almost no crop.