宁夏稻区年雨量200—300毫米,主要集中在7、8、9三个月。水稻于5月底或6月初撒布,9月中下旬收获。稻瘟病流行过程的特点是叶瘟发生得晚,发展也慢,到7月中旬拔节至孕穗期出现急性型病斑,8月上旬抽穗期才普遍发病。这样,叶瘟的上升便一直与穗瘟期连接起来。主要为害是穗瘟。本区稻瘟的流行也是以穗 Ningxia rice area annual rainfall of 200-300 mm, mainly concentrated in 7,8,9 three months. Rice is sprinkled in late May or early June and harvested in late September. The epidemic of rice blast is characterized by late occurrence of leaf blast, the development is also slow, to the mid-July emergence of acute lesions from the jointing to booting stage, heading early in August before the general incidence. In this way, the rise of leaf blast has been linked with the panicle blast. The main damage is panicle blast. The prevalence of rice blast in this area is also spike