一、蔬菜苗期常见几种病害1、猝倒病:在幼苗未出土或刚出土时发生较多,大苗发生率小。幼苗未出土发病的,胚茎和子叶腐烂。出土幼苗发病的,在幼茎基部出现水浸状黄褐色病斑,随后病斑缢缩变细呈线状,幼苗枯死,倒伏。在苗床上,开始是个别苗子发病,几天后向周围扩展,最后引起成片苗倒。 First, the vegetable seedling common several diseases 1, damping off disease: in the unearthed seedlings or just unearthed more, the incidence of large seedlings is small. Emergence of seedlings unearthed, embryo stems and cotyledons decay. Unearthed seedlings pathogenesis, the emergence of young stems at the base of the dip-like tan spots, shrinking thin lesions was linear, seedlings withered, lodging. In the seedbed, the beginning of the individual seed disease, spread to the surrounding after a few days, and finally caused into pieces of seedlings down.