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今春低温、寡照天多,有利于甘蓝菌核病的发生,提请广大菜农及早动手防治,以减轻危害。一、症状特点幼苗感病后,叶片出现水渍状淡褐色病斑,边缘不明显,病部组织软腐引起猝倒。包心期受害,在近地面的菜帮和茎基部产生水渍状凹陷病斑,开始呈淡褐色,后变成褐色或灰白色,发病部位腐烂。环境潮湿时,发病部位长出白色绒毛和黑褐色菌丝体,并形成黑色老
This spring low temperature, more than a few days, is conducive to the occurrence of cabbage scab, drew the majority of vegetable farmers early start prevention and control in order to reduce the harm. First, the symptoms of symptoms After the seedling flu, the leaves appear water-like light brown spot, the edge is not obvious, disease caused by tissue soft rot decoction. Caused by the heart of the package, in the near-ground dishes and stems at the base of water-like depression-like lesions, began to light brown, later turned brown or gray, the incidence of decay. When the environment is humid, the incidence of white fluffy hair and brown mycelium, and the formation of black old