Generally speaking, the calories of 100 grams of watermelon are about 25 kcal, which means that an 8 to 10 kilogram watermelon can provide 1,000 to 1,250 kcal of calories. A bowl of rice (200 grams) The calories are approximately 230 kcal. A larger watermelon is almost equivalent to 8 bowls of rice. Moreover, most of the sugar in watermelon is fructose. The characteristic of fructose is that it is not easy to feel full when eating. Therefore, it is difficult to control the intake when eating watermelon, and it is easy to eat too much accidentally.
Watermelon is an annual vine of the Cucurbitaceae family. It is also called summer melon and cold melon. Watermelon is a vine with slender vines with leaves that are opposite and triangular in shape. Around February, spherical or oval-shaped fruits will be produced on the vines. After maturity in May, they will become larger in size. The outer skin has dark green and light green stripes, the flesh is red, and there are black seeds inside the fruit.
Watermelon likes high temperature and dry climate. The suitable growth temperature is 25-30℃, and it is susceptible to cold damage at 6-10℃. Open field cultivation is only possible in areas where the average monthly temperature is above 19°C for more than three months throughout the year. It is a long-day plant that likes strong light, with a light saturation point of 80,000 lux. Suitable for hot and dry climate, strong drought tolerance, requires sandy loam with good drainage and deep soil layer. The optimum soil pH is 5 to 7. Watermelon cultivation methods are diverse in China. Those that belong to the open field include dry pond cultivation and sand field cultivation in the northwest, flat border cultivation in North China, and sorghum cultivation in the south of the Yangtze River. Those that belong to protected areas include wind barrier cultivation in Beijing, reed hair cultivation in Baoding, as well as plastic film covering cultivation and plastic cultivation. Greenhouse cultivation, greenhouse cultivation, etc.
Whether it is cultivated in the open field or in a protected field, the seedlings are first raised in the protected field in spring and then transplanted. The base fertilizer is mainly organic fertilizer, combined with superphosphate and potassium sulfate to increase the sugar content of the fruit. The planting density is generally 500 to 600 plants per mu. In North China, if branches are pruned, one plant will have one vine and one melon; in South China, if branches are not pruned, one plant will have many vines and many melons. It takes about 80 to 120 days from sowing to harvest, and about 30 to 50 days from female flowers opening to fruit maturity. The main diseases include fusarium wilt, anthracnose, powdery mildew, etc. The main pests include aphids, seed flies, melons, etc.