The heat preservation performance of greenhouse is poor, especially in summer and autumn, and the temperature is easy to be too high at noon, so it is necessary to do a good job of cooling down: 1. Cover the sun visor. There is a sunshade cover on the roof of the shed, and commonly used are sunshade nets and grass curtains. Covering the shed roof with two layers of sunshade net, the inner layer is close to the plastic film, the outer layer is about 15 cm ~ 20 cm away from the shed roof, and about 1.5m~2m ~ 2 m is hoisted from both sides of the shed to form an outer corridor to prevent direct sunlight on both sides. The straw curtain is directly covered on the plastic film, so there is no sunshine in the shed. In addition, planting vines around the greenhouse and using green shading can also reduce the temperature in the greenhouse. ? 2. Spray water on the roof. During the high temperature period, spray water every 1 hour 1 time from 9: 00 am to 3: 00 pm. ? 3. Strengthen ventilation. After sunrise on a sunny day, uncover the films on both sides of the greenhouse for ventilation; When the temperature in the shed drops below the feeding temperature at night, put down the films on both sides to keep warm. When the temperature is high, it is ventilated day and night. In rainy days, put down the sunshade nets on both sides of the greenhouse and lift the films on both sides of the greenhouse to facilitate ventilation. ? 4. Suitable for feeding wet leaves. The temperature in the shed is high, and it is easy to cause mulberry leaves to wither after ventilation. Wet leaves can be fed at noon on sunny days, and bleaching powder solution with 0.3% available chlorine concentration can be sprayed in the air to replenish water and prevent diseases. (Zhou Qian)