立枯病:育苗期的病害。苗根部或根颈部变为红褐色,严重时大量死苗。叶斑病:主要为害叶片,初期叶片上出现黄绿色水清状斑,后变圆形斑及不规则斑。严重时叶片枯死,甚至全株倒伏。斑枯病:为害叶、叶柄、茎。从老叶先发病,后传染到新叶片,初期呈淡褐色小斑点,后扩大坏死,另一种病斑外面有一个圈呈黄色。 Blight: seedling disease. Roots or root of the seedlings into a reddish brown, severe dead seedlings. Leaf spot: the main damage leaves, the early leaves appear yellowish green watery spots, after the round spots and irregular spots. Severe leaves withered, even whole plant lodging. Spot Blight: damage leaves, petioles, stems. The first disease from the old leaves, after infection to the new leaves, the initial light brown spots, expand necrosis, the other outside of a lesion has a yellow circle.