Shading nets are mainly used in summer, especially in the South where they are widely promoted. Some people describe it as white in winter in the north (covered by film), and black in summer in the south (covered with sunshade nets). The use of sunshade nets to cultivate vegetables in the south in summer has become a major technical measure for disaster prevention and protection. The northern application is also limited to summer vegetable seedlings. In summer (June-August), the main function of covering the sunshade net is to prevent the scorching sun, the impact of heavy rain, the hazard of high temperature, the spread of pests, and especially play a good role in preventing the migration of pests.