农作物病害是严重影响其产量的主要灾害之一。合理利用抗病良种,预防农作物病害流行,延长良种的使用寿命,使其与育种速度相适应,是保证农作物稳产高产的主要的农业技术措施之一。合理种植抗病品种——即合理种植具有不同抗性及抗源的抗病品种,辅之以正确轮作,可减轻寄主对寄生物的生态压力,而降低寄生物发生变异产生新的致病力强的小种;即使有新小种产生,由于不同抗性及抗源的品种合理搭配种植,也会减缓新小种的繁殖速度,稳定寄生物群体组成,从而减缓抗病良种的抗病性 Crop diseases are one of the major disasters that have a serious impact on their production. Rational use of disease-resistant varieties, prevention of crop disease epidemics, to extend the service life of elite, make it compatible with the breeding speed is to ensure stable and high-yield crops one of the main agricultural technology. The rational cultivation of resistant varieties - that is, the rational cultivation of resistant varieties with different resistances and sources of resistance, supplemented by proper rotation, can reduce the host ecological pressure on parasites and reduce the occurrence of parasitic mutations resulting in new virulence Strong races; Even if there is a new race, due to different resistance and resistance to species with reasonable planting, will also slow the propagation of new races, stabilize the composition of parasite population, thereby slowing disease resistance of resistant varieties