叶枯病是大蒜上的主要病害之一，对大蒜的产量和品质影响很大，近年来有加重发生趋势。发病重的田块减产幅度可达20％以上。1．发病症状该病主害叶片和花梗。叶片多为叶尖开始发病，逐渐向下扩展，出现不规则或椭园形灰褐色病斑。潮湿条件下病斑上出现黑色霉状物，严重时病叶枯 Leaf blight is one of the main diseases on garlic, garlic production and quality of a great impact in recent years, increasing the trend. The incidence of heavy plots yield reduction of up to 20%. 1. Symptoms of the disease the main leaves and pedicels. More leaves for the onset of disease tip, and gradually extended down, there are irregular or oval brown spots. Black mildew appears on the lesion in humid conditions, and leaves the leaves dry in severe cases