Improve the photosynthesis intensity Select a low-temperature anti-aging non-drip film to keep the shed film clean, wipe the film once every 7 days, remove the dust on the film and enhance the transparency. It can also be extended by artificial fill light. Increase the carbon dioxide content After 9:00 am on the sunny day, open the vents and ventilate. When the temperature is low, the vents should be small. The coke carbon dioxide generator is used to release carbon dioxide when the coke is fully burned; concentrated hydrochloric acid is placed in a corrosion-resistant container, and a small amount of lime is added to generate carbon dioxide by a chemical reaction; the dry ice is directly released in the shed. The period of carbon dioxide application is mainly in the period of growth of watermelon, especially in the fruit development period. The suitable time for application is around 10:00 am, and the concentration is 0.1% to 0.5%. Reducing the supply of nitrogen to watermelons should reduce the supply of nitrogen and increase the amount of potassium. In the application of the expanded melon fertilizer, each plant is added with 15 to 20 grams of potassium sulfate. In particular, the absorption of nitrogen by the plants in the late growth stage of the watermelon is controlled. At this time, if the nitrogen is absorbed, the quality of the watermelon will be lowered, because at this time, the watermelon is reduced. No longer grows, excess nitrogen accumulates in the melon, which in turn makes the sweetness and flavor of the watermelon worse. During this period, the increase in side vines is the expression of excessive nitrogen. Increase the temperature difference between day and night. The higher temperature during the day can increase the intensity of photosynthesis. Lowering the temperature of the greenhouse after sunset can reduce the respiration intensity of the plant, reduce the consumption of sugar, and make more sugar stored in the melon, which is beneficial to the accumulation of sugar. Improve the sweetness of watermelon. In the late stage of watermelon growth, ventilation is enhanced, and the temperature difference between day and night in the shed can be artificially increased. Controlled pouring of fruit before harvesting began to develop until 2 to 3 days before harvesting. Environmental conditions and cultivation measures played a decisive role in the quality of watermelon. Therefore, watering should be stopped 5 days before the watermelon harvest, which can increase the sweetness of the watermelon. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Foam Fire Extinguisher,Foam Extinguisher,Foam Annihilator,Foam Type Extinguisher JIANGSU NEW FIRE FIGHTING TECHNOLOGY CO.,LTD , https://www.ffo2cylinder.com