In 2001, the continuous high temperature and drought in most parts of China caused the watermelon to stand up in the flowering period. According to the study, the main reason is that due to the high temperature and drought conditions in the weather, the humidity in the air is small, and the soil moisture content is low. In the process of growing watermelon plants, although there are male flowers, the pollen of the male flowers is not well developed, resulting in the inactivity of the pollen sperm. Female flowers cannot be fully fertilized, so watermelons do not produce melons and form melons. In actual production, encountering the above climate, coupled with partial application of nitrogen fertilizer by melon farmers, is also an important reason for causing melon. When the temperature is high and drought, the male flowers of the watermelon will be stunted. At this time, a large number of watering irrigation will be performed. Due to the partial application of nitrogen fertilizer, the watermelon plants will grow indefinitely, thus making it difficult for the watermelon to stand. If this happens, the following measures should be taken immediately to restore the loss and achieve a good harvest. 1. When the length of melon vines does not exceed 1.5 meters, if the above-mentioned unfavorable climate occurs, water and phosphate water should be promptly applied. The ratio is 5000 parts per thousand, that is, 1000 kg of water should be added with 5 kg of phosphate fertilizer or potassium dihydrogen phosphate, 2.5 kg per plant. Phosphorus fertilizer. 2. When the length of melon vines does not exceed 3 meters, there are female flowers on the plants, and artificially-assisted pollination should be carried out on the few seed watermelon varieties, such as the special Daqing Hongbao watermelon king, the Qingfa eighth, the lesser seed tyrant dragon, and the less seed dark green king. The pollen of ordinary watermelon varieties such as Qingnong III, Jingxin No.1 and Admiralty Guanlong can be pollinated. The method of pollination is: Before 5 o'clock in the morning, pick male buds of ordinary watermelon, and put male flower buds in pots, cups, or containers that can maintain the humidity, and cover the plant leaves on the containers to keep the humidity. At 6-9am, when the female flowers are open, the males that are picked will naturally open and can be pollinated artificially. Each male flower can grant 2-3 female flowers. 3. When the seed length of the watermelon seedlings is less than 3 meters, there are female flowers on the plants, and when there are no male flowers of ordinary watermelon varieties, the male flowers can be cultivated in their own land to produce active male pollen. The method is: a small piece of land in the watermelon field (generally, 30-50 plots per mu of melon field is sufficient). Planting male plants to water five thousandths of phosphate fertilizer can also be used. Potassium dihydrogen phosphate is used instead. The ground also has to be wetted to create a microclimate with relatively high humidity, and then the males of this plot are collected to pollinate watermelon plants in other plots. 4. When the melon vine grows to 3-5 meters, there are no female flowers on the plant. Immediately cut some of the three vines. Each vine should be 1.5 meters long, so that the new vines will grow again and stay on the new vines. During the drought and water shortage, five-thousandths of the amount of phosphate fertilizer was poured. 5. When the watermelon planting density is too large (more than 500 plants per acre), some plants should be removed and the number of plants under the control of 500 plants per acre is better. It is better to leave 350 plants per acre to increase ventilation and light transmission. Then follow the above approach.