在水稻生产上,采用抗病丰产良种是防治稻瘟病的有效经济措施,但抗病品种在栽培过程中会逐渐丧失其抗性。例如农垦58、矮南早1号品种,六十年代初期在郊区广泛种植,是抗病丰产良种。但种植几年后,稻瘟病逐年加重,已变为感病品种。品种丧失抗病性的原因很多,除不良环境条 In rice production, the use of disease-resistant high yielding varieties is an effective economic measure to control rice blast, but resistant varieties will gradually lose their resistance during the cultivation process. For example, Nongken 58 and Dwarf Nannan No.1 varieties were widely planted in the suburbs in the early 1960s and were highly resistant varieties with high yield. However, after several years of planting, the rice blast has been increasing year by year and has become a susceptible variety. There are many reasons for the loss of disease resistance, except for bad environmental conditions