一、稻瘟病的发生相北日本型 [苗瘟(播种、栽秧早的地区;随着盘育苗技术的推广而构成生产问题)]→叶瘟(病势扩展期在幼穗分化期以后)→穗瘟(和叶瘟发生轻重关系密切)。南日本型苗瘟(播种、栽秧晚的地区)→叶瘟(病势扩展期在幼穗分化期以前)→穗瘟(枝梗瘟发生多) First, the occurrence of rice blast Phase North Japan [Miao blast (sowing, early planting areas; with the promotion of the plate cultivation technology constitutes a production problem)] → leaf blast (disease spread in the panicle after the panicle) → spike Plague (and severity of the occurrence of leaf blast close). Southern Japan seedling blast (sowing, late planting areas) → leaf blast (spread of the disease in young panicle before the period of differentiation) → panicle blast (paroxysm and more)