温室、大棚、立壕等保护地栽培蔬菜,病虫害发生严重,必须注意防治。一、蔬菜苗期病害(简称苗病)蔬菜苗病的症状,因蔬菜种类、发病时期和致病原因不同而异。在幼苗子叶刚展开时,茎基部呈水浸状变褐软化,很快倒折。倒折初期病苗茎叶尚保持绿色,不久腐烂,潮湿时病苗残体及附近床土表面长出一层白色棉絮状霉层。因幼苗得病后猝然倒折而得名“猝例病”。当幼苗长出真叶 Greenhouses, greenhouses, vertical trench and other protected areas to cultivate vegetables, pests and diseases serious, we must pay attention to prevention and treatment. First, the vegetable seedling disease (Miao disease) Vegetable seedling symptoms, due to the type of vegetable, the onset of disease and causes vary. Cotyledon just seedlings in the newly opened, the base of the stem was brown-soaked softened, and quickly fold back. In the early stage of folds, the leaves and stems of the disease still remain green, and soon they decay. When the dampness leaves, the surface of the soil and bed soil grows a layer of white cottony mildew. Suddenly after the disease due to seedling inverted fold named after the “disease”. When the seedlings grow true leaves