In the selection of greenhouse film, in addition to the high transparent film in cold areas, scattering film with suitable haze should be selected according to local climatic conditions, production seasons and growth habits of cultivated crops. In areas with good atmospheric transparency and high intensity of sunlight and spring, summer and autumn; A high-haze and high-scattering film should be selected; For wintering production sheds in cold areas, high thermal insulation, high light transmission and high scattering film should be selected; For wintering production sheds in mild climate areas, high transmittance and high scattering greenhouse film should be selected.
After the light passes through the medium, it will form direct light and scattered light that does not change the direction, the larger the proportion of direct light, the lower the haze of the greenhouse film, the better the transparency, the larger the proportion of scattered light, the higher the haze of the greenhouse film, the lower the transparency. According to our research, the shed film with astigmatism function can effectively prevent the scorched black edge of red roses; can greatly reduce the proportion of grape "sunfruit"; It can promote uniform coloration of tomato fruits. When choosing greenhouse film, it is also necessary to consider the special requirements of cultivated crops for light, such as fungi are mostly required to be produced under weak light or even light protection conditions, and high haze, low light transmission or even opaque film must be selected.