Types of watermelons commonly covered with plastic film

First, the ordinary transparent film is the earliest and most popular plastic film, with a light transmittance of about 80% to 94%. It has a certain intensity, can withstand the wind and rain in the growing season, and can increase the ground temperature by 2 to 4 ℃. Generally, the film is 0.007 to 0.02mm thick and 50cm to 150cm wide. Second, the silver gray film has strong reflectivity, can enhance the reflected light intensity of the border surface, and can repel aphids, so it can be used as a special film for repelling aphids. Third, black film, with shading effect, can increase soil temperature by 1 to 3 ℃ in spring, effectively prevent soil water evaporation and restrain weeds. The yield-increasing effect of black film is about 30% higher than that of ordinary transparent film.