High temperatures and droughts cause a large number of watermelons that are inflated to burst. Fruit cracking during fruit enlargement is mostly caused by severe changes in soil moisture. Sudden flooding after continuous drought or continuous heavy rain, a large number of nutrients enter the fruit, so that the melons grow much faster than the peel, the formation of cracking; In addition, the general thin-skinned varieties of watermelon cracking fruit, such as Huang Xiaoyu, Hong Xiaoyu, etc., skin thickness is only 0.5 About centimeters, when the fruit will mature, in the event of a slight cracking vibration, continuous rain and continuous drought, flooding, will cause a lot of cracking. Prevent method: 1, should choose the appropriate thickness of watermelon varieties, generally 1 - 1.5 cm thick is appropriate. 2. The watermelons are planted on the surface of the grass and leave the leaves before and after the fruit set, covered with leaves to prevent direct sunlight from the fruits. 3, appropriate furrow irrigation, according to the wilting and recovery status of the leaf to determine the extent of water shortage, combined with local weather forecast, to ensure that the recent 3-4 days without drip irrigation under the premise of furrow irrigation, water should be uniform. 4. In order to prevent sudden fruit drop caused by heavy rain after continuous drought, nutrients can be properly controlled to flow into fruit. The specific method is as follows: Select two small bamboo sticks with a width of 1/3 of the stem diameter and insert the melon vines vertically; use a pin instead of a bamboo stick to insert the stems vertically; hand twist the vines or handles etc. To achieve the purpose of reducing cracking.