玉米黑粉病在任丘市晚春播玉米上发生较严重,而夏玉米上发生很轻,是近年来发生最严重的一种病害,这主要和气候因素及品种特性有关。一、症状特征:玉米黑粉病又名瘤黑粉病,是常见的玉米病害之一,由玉米黑粉菌侵害所致。该病菌可侵染玉米幼苗、茎节、腋芽、雌穗、雄穗、叶片和根的幼嫩分生组织,形成形状、大小不同的瘤状物。病瘤初为白色,内部亦为白色,肉质多汁,迅速膨大后逐渐变黑,外膜破裂后散出大量黑粉。玉米黑粉病虽属局部侵染性病害,但在 Corn powdery mildew occurred more severely on late spring sowing in Renqiu City, while it occurred very lightly on summer corn, which is the most serious one occurring in recent years. It is mainly related to climatic factors and variety characteristics. First, the symptoms and signs: corn powdery mildew Also known as powdery mildew, is one of the common maize diseases, caused by the infection of corn black powder. The bacteria can infect corn seedlings, stem nodes, axillary buds, ear, tassel, leaves and roots of the young meristem, the formation of the shape and size of the tumor. The beginning of the tumor is white, the interior is also white, juicy succulent, rapidly swollen and gradually black, rupture of the outer membrane after the release of large amounts of black powder. Although corn powdery mildew is a locally invasive disease, but in