Self shade net in Division I since the promotion, because of its convenient management, coverage performance is superior to the traditional straw, improve the yield and quality of the vegetables, broaden the market space, economic benefits is significantly higher than that of the open field vegetables, already more and more get the welcome of broad vegetable grower. At present, our city of shade area is increasing year by year, already amounted to about 2500000 m2. The use of shade net is one-time investment is large, the cost is higher than that of the open field vegetables, our city to solve this