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西瓜炭疽病是为害西瓜的一种常发病,一股西瓜受害可减产3～4成,严重时可导致失收。为此,我们在1984～1987连续四年对该病的发生消长规律进行了观察研究,同时在防治技术方面开展了实验探索,并进行了总结、推广应用。一、发病症状病菌能侵染西瓜的叶片、叶柄、茎、果实。幼苗受害后,近地表茎基变褐,缢缩倒苗。叶片被侵染后,初为水渍状近圆形黑色病斑、后变为黑褐色,并着生许多小黑点。茎和叶柄受害,初为水渍状黄褐色斑,短期内即可变为长圆形黑色稍凹陷病斑。幼瓜受害,一般呈现畸形,极易早期脱落。果实上初为水渍状绿色圆斑,扩大后变为较大的深褐色略凹陷病斑,并可见小黑点(分生孢子盘),潮湿时可形成浅红
Watermelon anthracnose is a common disease that damages watermelon. An injury of watermelon can reduce the yield by 3 to 4 percent. In severe cases, it can lead to the loss of watermelon. Therefore, we observed and studied the growth and decline regularity of the disease for four consecutive years from 1984 to 1987. At the same time, we carried out experimental exploration on the prevention and treatment technology, and summarized, popularized and applied it. First, the symptoms of pathogens can infect watermelon leaves, petioles, stems, fruits. After the seedlings are injured, near the surface of the base brown, 缢 shrink down seedlings. After the leaves were infected, the initial water stains nearly circular black lesions, after turning into dark brown, and with many small black spots. Stem and petiole victims, the initial water stain yellow brown spots, short-term can become oblong black slightly depressed lesion. Suckling victims, the general deformity, very easy to fall off early. Fruit early as a water-like green spot, expand into a larger dark brown slightly depressed lesion, and can be seen black spots (conidia disk), damp can form a red