一、发生规律上年遗留在土壤病残体中的菌核春季萌发,释放子囊孢子随气流扩散传播,为初侵染源,飘落在植株上的孢子产生菌丝,侵入衰老叶片、花瓣引起发病。一般油菜盛花期为发病始盛期,随着发病的花瓣老叶败落至植株其他部位,常在主茎叶柄或分枝处形成病斑,或通过败 First, the law Occurred in the last year in the soil disease residual body of the sclerotium germination in spring, the release of ascospores with air diffusion spread as a primary source of infection, spores falling on the plant mycelium, invade the aging leaves, the petals cause disease . The general rape blooming period for the onset of onset, with the incidence of the old leaves of the petals fall to other parts of the plant, often in the main stem petiole or branch to form a lesion, or by defeat