The insect net is a new type of agricultural covering m […]
The insect net is a new type of agricultural covering material. It is made of high-quality polyethylene as raw material, adding anti-aging, anti-ultraviolet and other chemical additives. It is woven by wire drawing and looks like window screen. It has the characteristics of tensile, heat resistance, water resistance, corrosion resistance, non-toxic and tasteless. The correct storage life can reach 3-5 years. In addition to the advantages of the shade net, the vegetable insect net has the biggest feature of preventing insects and preventing diseases and greatly reducing the amount of pesticides. It is a key technology for pollution-free vegetables and a simple, scientific and effective pest control measure.
First, the principle of pest control and disease prevention of insect nets
The insect-proof net uses artificially constructed barriers to reject pests outside the net to achieve the purpose of preventing insects, preventing diseases and keeping vegetables. In addition, the light reflected and refracted by the insect net has a certain repellent effect on pests.
Second, the role of insect nets
1. Insect-proofing: After the vegetables cover the insect-repellent net, they can basically eliminate the pests such as cabbage caterpillar, diamondback moth, cabbage moth, Spodoptera litura, yellow-curved beetle, locust leafhopper, and aphid. According to the test, the insect-proof net has a control effect of 94--97% on cabbage cabbage, diamondback moth, cowpea pod, and Liriomyza sativa, and 90% control effect on aphids.
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 the temperature, soil temperature and humidity: Tests show: in the hot July-August, in the 25-mesh white insect net, the morning and evening temperatures are the same as the open, while the sunny noon is 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 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. Insect net technology
4. Covering strong light: In summer, the light intensity is high, strong light will inhibit the vegetative growth of vegetable crops, especially leafy vegetables, and the insect net can play a certain role of shading and anti-glare, 20-22 mesh silver gray insects The net general shading rate is 20-25%.
Third, the choice of mesh
Pay attention to the aperture when purchasing vegetable insect nets. Vegetable production is preferably 20-32 mesh, and the width is 1-1.8 m. White or silver-gray insect nets work better. If the shading effect is enhanced, a black insect net can be used.
Fourth, the use of insect nets
1. Covering the greenhouse: Cover the insect-proof net directly on the large scaffolding, and compact it with soil or brick. The top line of the shed should be tight to prevent strong winds from opening in summer. Leave the front door open for easy access. Usually go in and out to close the door, in order to prevent the butterfly moth from flying in the shed to lay eggs. At the same time, it is necessary to check the insect net frequently for tearing (especially for a long service life). Once it is found, it should be repaired in time to ensure that there is no pest invasion in the net room.
2. Covering the small arch shed: inserting the bamboo or steel bar into the arch shed and inserting it into the surface of the field, covering the insect net with the insect net, and then pouring it directly on the net, until the harvest is not uncovered, and the whole closed cover is implemented.