一、西瓜蔓枯病该病是由真菌引起的。主要侵染茎蔓和叶片,以叶片受害最重。叶片受害,最初出现褐色小点,有不明显的同心轮纹,空气潮湿时,全叶枯死。二、西瓜叶枯病西瓜叶枯病为真菌性病害。西瓜叶枯病主要危害西瓜的叶部。子叶发病初期多在叶缘生水浸状小点,扩展到整片子叶后干枯。真叶发病在叶背面叶缘或 First, the watermelon disease is caused by the fungus. Mainly infected stems and leaves, the most affected leaves. Leaves damage, the initial brown spots, there is no obvious concentric ring pattern, the air is humid, full-blown dead. Second, watermelon leaf blight Watermelon leaf blight is a fungal disease. Watermelon leaf blight the main damage to the leaf of watermelon. The early onset of cotyledons at the edge of leaves flooding-like dots, extended to the whole film cotyledons dry. True leaf disease in the leaves on the back of the leaf margin or