正确选用棚膜是搞好棚菜生产的重要环节。目前,市场上销售的棚膜大体分四类,即无滴膜、有滴膜、复合膜和紫光膜。1.无滴膜。覆盖后,棚膜内面水滴能顺斜面流下,膜下无停留水滴,透光好,棚内温度比有滴膜平均高3摄氏度-5摄氏度,十分有利于冬季棚菜生产和安全越冬。膜下无水滴滴落,棚内湿度小,大大减轻各种病害的发生。棚内温度高、光照好、病害轻 Proper selection of greenhouse film is an important part of greenhouse production. At present, the market sales of film generally divided into four categories, namely no drip film, a drop film, composite film and purple film. No drip film After covering, the water droplets on the inner surface of the film can flow down the bevel, no water drops remain in the film, and the light transmission is good. The temperature inside the shed is 3 degrees Celsius -5 degrees Celsius higher than that on the drip film, which is very beneficial to winter shed production and safe wintering. Under the membrane, there is no dripping of water and little humidity in the shed, which can greatly reduce the occurrence of various diseases. High shed temperature, light, light disease