白菜霜霉病(Peronospora parasitica(Pers.)Fr.)在北方春、秋两季白菜和种株上为害,秋白菜受害更为严重。主要是叶片、茎、荚和种子受害,直接影响白菜产量和品质。初次侵染来源是枯叶中的卵孢子和种内潜伏菌丝。种内带菌尚需进一步证实。为此于1983～1984年进行了白菜霜霉病种子带菌检验及种子处理试验。 Cabbage downy mildew (Peronospora parasitica (Pers.) Fr.) On the northern spring and autumn cabbage and plant damage, autumn cabbage more serious victims. Mainly leaves, stems, pods and seeds of victims, a direct impact on cabbage yield and quality. The primary sources of infestation were oospores and intraspecific latent hyphae in dead leaves. Inoculation species still need further confirmation. To this end in 1983 to 1984 carried cabbage downy mildew test of seed germination and seed treatment.