The uncovering and shading net should be flexibly controlled according to the weather conditions, vegetable types and the requirements of light intensity and temperature in different growth periods. Generally, cover in sunny and cloudy days, cover in noon, cover in morning and evening, cover in early growth stage and cover in late growth stage. The shading net should be removed 7 days before harvesting to avoid reducing the quality of vegetables.
Vegetables are grown in summer and covered with shade nets for shading and cooling. There are many types of shading net, different specifications, different colors of shading net, shading rate and cooling effect are different, different kinds of vegetables, the requirements of light intensity are also different. Therefore, the suitable shading net should be selected according to the vegetable species and the light intensity during the covering period. For example, the commonly used black shading net has high shading rate, fast cooling, suitable for short-term coverage, not long-term coverage, especially for sunny vegetables.