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冬春大棚蔬菜(西红柿、辣椒、瓜类等)苗期,极易患猝倒病和立枯病两大病害。一、病害症状1.猝倒病:蔬菜的整个幼苗期均可发生。幼茎发病在接近地面处,病部呈水渍状黄褐色,并逐渐腐烂。幼苗发病后很快倒伏,几天后成片死亡。在湿度高时,病部密生白色霉状物。湿度越高,危害越重。2.立枯病:主要危害刚出土幼苗和大苗。初期茎部产生长圆形暗褐色病斑,病斑逐渐凹陷扩大绕茎一周。根部受害,皮层腐烂,随后叶片变黄枯死。潮湿时,病部常有淡褐色蛛丝状霉物。二、防治方法1.加强苗期管理:出苗后应选择温暖晴天揭膜炼苗、通风换气,严格控制苗床温湿度。白天床温应控制在20℃
Spring and winter greenhouse vegetables (tomatoes, peppers, melons, etc.) seedling stage, extremely susceptible to damping off and damping off the two major diseases. First, the symptoms of disease 1. Damp down disease: vegetables can occur throughout the seedling stage. Young stems close to the onset of the disease at the ground, watery yellowish brown lesions, and gradually decay. Seedlings soon after the onset of lodging, a few days after the film died. In high humidity, the disease dense white moldy things. The higher the humidity, the harder it is. 2. Blight: The main hazard just unearthed seedlings and seedlings. Early stems produce oblong dark brown lesions, lesion gradually concave to expand around the stem for a week. Root damage, cortical decay, followed by the leaves turn yellow dead. When wet, the diseased parts often have a light brown spider filamentous mold. Second, the prevention and treatment methods 1. Strengthen seedling management: After emergence should choose a warm sunny day Jiemo, ventilation, strict control of seedbed temperature and humidity. Daytime bed temperature should be controlled at 20 ℃