水稻细菌性褐条病往年很少发生,今年4月下旬至5月初在我县联圩、昌邑、大塘、观咀、象山等乡秧田大面积发生,发生面积达1,500多亩。受害重的田块病株率达100％,有的秧田成片死秧。一般发病田块病株率达20—25％;受害秧苗一般二叶一心或三叶一心期。秧苗发病先在叶鞘上出现褐色小点,逐渐向上下蔓延成褐色条斑。有的秧苗没有任 Rice bacterial brown streak rarely occurred in previous years. From late April to early May this year, a large area of ​​rice seedlings occurred in the counties, Changyi, Datang, Guantai and Xiangshan in our county, with an area of ​​over 1,500 mu. Victims of the heavy field of diseased plants rate of 100%, and some seedlings died of seedlings. The general incidence of disease rate of 20-25% field plots; victims of seedlings generally one leaf or one leaf clover one heart phase. The emergence of seedlings first appeared in the leaf sheath brown spots gradually spread up and down into brown streaks. Some seedlings without any