甜瓜适宜套种,经济效益高,是粮棉地区的重要经济作物。但是随着甜瓜栽培面积的扩大,其病害也加剧,尤其是急性萎凋症危害严重。一般在果实膨大期,中午出现甜瓜叶子萎凋,傍晚恢复正常,第二天叶子萎凋后再也不能恢复正常而枯死。现将其发生原因与防治方法介绍如下: 一、发生原因 （一）瓜地是砂质壤土,容易干操,加之连年施用苦土石灰,土壤硝化,引起钙和镁的吸收性变差,植株生长瘦弱,钙盐集聚在土壤中,对植物生长发育更为不利。 （二）坐果过多。植株结一个果的大部分并不枯死,因为此时植株的同化养分大部分流向第一个果实,而结了第二个果的由于得不到足够的养分,生长就会停止。 （三）整枝不彻底。留有1-2个弱小侧枝的植株不会枯死.整枝过重而没有侧枝的植株则枯死。 （四）设施栽培时,温度高且灌水少,较易发生。 （五）塑料钵育苗,幼苗根数少而且容易老化,定植后根系发育不好,也容易发生此症。 （六）嫁接质量差。砧木和接穗不亲和,或接活 Melon suitable for intercropping, high economic efficiency, is an important economic crops in cotton area. However, with the expansion of melon cultivation area, the disease is also exacerbated, especially acute wilt disease. Generally in the fruit swollen period, melon leaves wither at noon, returned to normal in the evening, the next day after the leaves wither can no longer return to normal and dead. Now the causes and prevention methods are as follows: First, the causes (a) Melon is sandy loam, easy to dry operation, combined with years of application of bitter soil lime, soil nitrification, causing deterioration of calcium and magnesium absorption, plant Thin growth, calcium accumulation in the soil, the plant growth and development more negative. (B) too much fruit. Most of the plants will not die because most of the assimilation nutrients in the plants flow to the first fruit, and the growth of the second fruit ceases due to lack of nutrients. (Iii) Pruning is not complete. Plants with 1-2 weaker side branches will not die, and plants that have too much but have no more side branches will die. (D) facilities cultivation, high temperature and less irrigation, easier to happen. (E) plastic pot seedlings, seedlings and easy to aging a small number of roots after planting poorly developed, but also prone to this disease. (F) poor quality of grafting. Rootstock and scion incompatible, or pick live