番茄叶霉病是常发和多发病,危害严重时减产20%～30%。一、症状叶片、叶柄、果实均可受害,但以叶片最为明显。开始发病时,叶背产生不规则或椭圆形淡绿色病斑,以后长出灰色霉层,病斑多时可相互结合。叶片正面病斑先呈淡绿色,后变淡黄色,严重时全叶枯死。发病一般从下 Tomato leaf mold is a frequent and frequently-occurring disease, with severe damage when cut by 20% to 30%. First, the symptoms of leaves, petioles, fruits can be affected, but the most obvious leaves. Beginning of the disease, the leaf back produce irregular or oval pale green lesions, later grow gray mildew, lesions can be combined with each other for a long time. The front of the leaves showed a pale green lesion, pale yellow after the change, severe full-blown dead. Generally onset from the next