Shed chambers have strong airtightness. In order to maintain heat and heat during the severe winter season, the ventilation coefficient is small and the time is short. This results in a lack of carbon dioxide in the greenhouse, which affects plant photosynthesis. Experiments have shown that before the expelling of the grass and the use of carbon dioxide gas fertilizer technology, it can generally increase production by 20% to 30%. After the exposing, the concentration of carbon dioxide in the greenhouse dropped sharply as the light and the effects of the vegetables proceeded. At 8 to 9 in the morning, there is only 150 to 200 PPM. If the ventilation is not timely, it will be even lower. Even with ventilation, the carbon dioxide concentration can only be increased to 300 PPM, and the vegetable crops are still in a state of carbon dioxide starvation. If vegetables stay in this state for a long time, their normal growth and development will be seriously affected. Precautions strictly control the carbon dioxide application concentration. The supplemental carbon dioxide concentration should be based on crop species characteristics, growth period, weather conditions and cultivation techniques. Do not over- or under-need, greenhouses need to be closed to reduce CO2 spillage and increase fertilizer efficiency. Reasonably arrange the application period and time. The effect of carbon dioxide in vegetables, watermelons, strawberries, and fruit trees at different growth stages is not exactly the same. For example, when soybeans were applied with carbon dioxide during flowering and podling, the effect of increasing production was more obvious than at the stage of vegetative growth. Tomatoes, cucumbers and other fruit and vegetable vegetables from planting to flowering, plant growth is slow, carbon dioxide demand is small, generally do not apply carbon dioxide, to prevent plant growth. The greenhouse vegetable began to apply carbon dioxide 7 to 10 days after the planting (slow seedling stage), and the greenhouse vegetables began to apply carbon dioxide 15 to 20 days after the colonization (seedling stage) and continued for 30 to 35 days. Fruits and vegetables should not be used to apply carbon dioxide before flowering and fruit setting, so as to avoid excessive growth caused by excessive nutrient growth and fruit drop. Applying carbon dioxide during flowering and fruit setting period has a significant effect on reducing fruit drop, increasing fruit setting rate and promoting fruit growth. Fruit trees have more obvious effects on the flower bud differentiation and fruit enlargement period. The application time is determined according to the light intensity after sunrise. Normally from November to February of next year, it is cast after 1.5 hours of sunrise; from March to mid-April, it is cast after 1 hour of sunrise; from late April to early June, it is cast after 0.5 hour of sunrise. After being cast, the greenhouse or greenhouse is closed for 1.5 to 2 hours and then released, usually once a day, and stopped on rainy days. Headband Mask,Dust Mask Protective,N95 Certification Mask,Coronavirus Design Disposable Face Mask KUTA TECHNOLOGY INDUSTRY CO.,LIMITED , https://www.kutasureblue.com