当前水稻生产上存在着一个严重减产因子——稻瘟病,一旦发生此病就会带来巨大的经济损失。以邛崃县为例:1984年五绵山区的颈稻瘟比平坝区严重,1985年据我们在水稻抽穗前调查,叶稻瘟的发病趋势则相反。原因就在五绵山区吸取了教训,及时淘汰1984年重感稻瘟病的“汕优2号”,扩大“双桂36”和“丛芦51”的种植面积。可见及时更新良种是减轻稻瘟 At present, there is a serious reduction factor in rice production - rice blast. Once the disease occurs, it will bring huge economic losses. Take Xuyi County as an example: In 1984, the population of neck blast disease in Wumian Mountain area was more serious than Pingba District. In 1985, according to our survey before rice heading, the incidence of leaf blast was the opposite. The reason is that Wumian Mountain has learned the lesson and promptly eliminated “Shanyou 2” which was highly susceptible to rice blast in 1984 and expanded the planting area of ​​“Shuanggui 36” and “Conglu 51”. Shows that the timely updating of the seed is to reduce the rice blast