The main effect is light, shading cover down greenhouse, cover net is an important measure of greenhouse vegetable production in high temperature season. But if the selection of inappropriate shade net, will not only cause the plant growth, but also not conducive to the flowering and fruit setting. So, we must scientifically and rationally choose shading.
Don't judge the merits of the shading color: currently on the market in black and gray shading. Black shading rate, faster cooling in the summer, should need to fine management field of short-term coverage; gray shading rate is low, suitable for light vegetables and long-term coverage. The quality of the net and is not the final say by the color, shading color is in the process of manufacturing raw materials added. So, different vegetables to choose different shading. For example, tomato is a light crop, and the plant grows strong and blooms earlier if it meets 11~13 hours of sunshine. Although the effect of light time on tomato is not so important, the intensity of light is directly related to the yield and quality. Insufficient light, easy to cause the plant nutrition, growth and flowering decreased. Tomato is 70 thousand lux light saturation point, light compensation point of 30 thousand ~3.5 000 lux, general summer noon light intensity was 90 thousand ~10 10000 lux. Black shading rate is high, up to 70%, the use of black shade net, the demand of the regular growth of light intensity is not up to the tomato, tomato is easy to cause growth and accumulation of photosynthate shortage. Most of the net silver and shading rate in 40%~45%, the light transmittance of ~5 million in the 40 thousand lux, can meet the demand of the regular growth of tomato. So the best coverage of net silver tomato.