中文摘要：

通过扣棚和不同浇水处理，对高温高湿和土壤水分与西瓜果肉恶变的关系进行了初步研究。结果表明，在高温条件下，土壤干旱和土壤过湿均使西瓜果肉恶变指数成倍增加，其中土壤干旱条件下果肉恶变指数最高。中午浇水的果肉恶变指数是早晨浇水的4-12倍。可见，土壤水分是引起西瓜果肉恶变的重要环境因子，土壤过于或过湿，午间高温时段浇水，导致地温剧烈变化是西瓜果肉恶变的重要原因之一。另外，阳光暴晒果实也是西瓜果肉恶变的诱因之一。

英文摘要：

Primary studies on relationship between high temperature and humidity and soil water with watermelon [ Citrullus lanatus （ Thunb. ） Matsum.et Nakai ] flesh degeneration were conducted by covering plastic tunnel and different irrigation treatments. The results showed that under high temperature, both soil drought and high soil humidity could cause the increase of watermelon flesh degeneration index, and the flesh degeneration index under soil drought condition was the highest. The flesh degeneration index of the plants irrigated at the noon was 4-12 times of that irrigated in the morning. These results indicated that soil water was an important environmental cause for watermelon flesh degeneration. Soil drought or high soil humidity and irrigating at noon were causes for watermelon flesh degeneration. Besides, exposure under sun could also lead to watermelon flesh degeneration.