The main function of shading net is to block strong light and reduce greenhouse temperature. Covering shading net is an important measure for sparse vegetable production in greenhouse during high temperature seasons. However, if an inappropriate shading net is used, it will not only cause the plant to grow excessively, but also be unfavorable for flowering and fruit setting. It is necessary to scientifically and reasonably use shading nets. Don't judge the quality of sunshades based on color: currently, the sunshades sold in the market are mainly black and silver gray. Black shading nets have high shading efficiency and fast cooling, making them suitable for short-term coverage in fields that require careful management in hot summer; The silver gray shading net has a low shading rate and is suitable for light loving vegetables and long-term coverage. The quality of the sunscreen is not determined by the color the final say The color of the sunscreen is added in the process of raw material manufacturing. 

So, different vegetables should choose different shading nets. For example, tomatoes are a light loving crop. As long as the daily flowering time of 11-13 hours is met, the plant will grow vigorously and bloom earlier. Although the effect of light duration on tomatoes is not as important, the intensity of light is directly related to yield and quality. Insufficient light can easily lead to malnutrition, elongation, and reduced flowering of plants. The light saturation point of tomatoes is 70000 lux, and the light compensation point is 30000 to 35000 lux. Generally, the light intensity at noon in summer is 90000 to 100000 lux. Black shading nets have a high shading rate of up to 70%. Using black shading nets, the light intensity cannot meet the normal growth needs of tomatoes, which can easily lead to excessive growth of tomatoes and insufficient accumulation of photosynthetic products. Most silver gray shading nets have a shading rate of 40% to 45% and a light transmittance of 40000 to 50000 lux, which can meet the normal growth needs of tomatoes. So it's best to cover tomatoes with a silver gray shading net.