The function of anti-insect nets.
1. Insect prevention:
After covering the insect-repellent net on the vegetables, the harm of various pests such as cabbage caterpillar, diamondback moth, cabbage moth, Spodoptera litura, yellow-curved beetle, locust leafhopper, and aphid can be basically eliminated. According to the test, the control effect of the insect-proof net on cabbage cabbage, diamondback moth, cowpea pod, and Liriomyza sativa is 94--97%, and the control effect on aphids is 90%.
2. Disease prevention:
Viral disease is a catastrophic disease on a variety of vegetables, mainly caused by insects, especially aphids. Because the insect net has cut off the main transmission route of pests, it greatly reduces the infection of vegetable viruses, and the control effect is about 80%.
3. Adjust temperature, soil temperature and humidity:
The test showed that in the hot July-August, in the 25-mesh white insect net, the morning and evening temperatures were the same as the open field, while the sunny noon was about 1 °C lower than the open ground. In the early spring of March-April, the insect-proof net covered the shed is 1-2 °C higher than the exposed ground, and the 5 cm ground temperature is 0.5-1 °C higher than the open ground, which can effectively prevent frost. The rain-proof net room can reduce the amount of precipitation in the net indoors, and the sunny day can reduce the evaporation in the net.
4.Shading:
In summer, the light intensity is large, and strong light will inhibit the vegetative growth of vegetable crops, especially leafy vegetables, while the insect net can play a certain role in shading and anti-glare. The 20-22 mesh silver-gray insect net has a general shading rate of 20 -25%.