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白绢病为胡萝卜的重要病害,主要在南方部分地区发生为害,保护地、露地都可发病,以保护地内发病重。常造成死苗和烂根,影响生产。在6~7月份高温多雨天气,时晴时雨,发病严重。气温降低,发病减少。酸性土壤,连作地、种植密度高,发病重。发病症状发病初期地上部症状不明显,植株根茎部接地处长出白色菌丝,呈辐射状,后在菌丛上形成灰白色至黄褐色小菌核,大小1毫米。病情严重时,植株叶片黄化、萎蔫。
Sclerotium is an important disease of carrots, mainly in some parts of the South damage, protected areas, open field can be disease to protect the incidence of severe disease. Often caused by dead seedlings and rotten roots, affecting production. In June to July hot and rainy weather, sunny when the rain, the incidence is serious. Lower temperature, reduce the incidence. Acid soil, cropland, planting density, severe disease. Symptoms onset early symptoms of the upper part of the obvious rhizomes Department of the ground at the growth of white mycelium, was radial, then formed in the flora gray to brown small sclerotium, the size of 1 mm. Serious illness, plant leaves yellow, wilting.