Brief introduction
Insect-proof net covering cultivation is a new environmental-friendly agricultural technology that can increase production and is practical. It can effectively control the spread of various pests, such as cabbage caterpillar, cabbage moth, diamondback moth, aphid, beetle, beet armyworm, Liriomyza sativae, Spodoptera litura, etc. and prevent the spread of virus diseases by covering the trellis to build an artificial isolation barrier to keep pests out of the net and cutting off the propagation path of pests (adults). And has the functions of light transmission, moderate shading of insect prevention nets, ventilation and the like, creates favorable conditions suitable for the growth of crops, ensures that the application of chemical pesticides in vegetable fields is greatly reduced, enables the produced crops to be of high quality and sanitary, and provides strong technical guarantee for the development and production of pollution-free green agricultural products. The insect net also has the function of resisting natural disasters such as storm, rain erosion and hail attack. Insect-proof nets are widely used for isolating pollen introduction when producing original seeds of vegetables, rape and the like, for isolating covers and pollution-free vegetables after tissue culture and virus elimination of potatoes, flowers and the like, and also can be used for insect prevention, disease prevention and the like during tobacco seedling cultivation, and are the preferred products for physical prevention and control of various crops and vegetable pests. Let consumers eat "rest assured vegetables" and make contributions to China's vegetable basket project.
Use
Insect-proof net not only has the function of shading the sun, but also has the function of preventing insects. It is a new type of material for preventing field vegetable pests. Insect net is mainly used for breeding and cultivation of cabbage, cabbage, radish, cabbage, cauliflower, eggplant, melons, beans and other vegetables in summer and autumn, which can improve seedling emergence rate, seedling formation rate and seedling quality. The application technology of the insect-proof net is introduced as follows:
Covering form
(1) the insect-proof net is directly covered on a large scaffolding frame, the periphery is tightly compacted with soil or bricks, the net is tightly fastened with a film pressing line, the net is used together with the film pressing line and a film rolling device, and the front door is left uncovered. (2) bending bamboo chips or steel bars into small arches, inserting the small arches on the surface of the field border, covering the insect-proof net on the arches, watering the small arches directly and then pouring the small arches on the net until the small arches are harvested, and completely covering the small arches. (3) Covering with horizontal scaffolding.
Covering growth period
The insect-proof net has less shading, does not need to be uncovered day and night or uncovered at the front and back, and should be covered in the whole process so as not to allow pests to invade, thus obtaining satisfactory insect-proof effect.
Soil disinfection
After harvesting the previous crops, the residues and weeds from the previous crops should be removed from the field in time and burned down. Ten days before the shed was built, water was drained to flood the vegetable plot surface for seven days, eggs of surface and underground pests and airborne bacteria were drowned, then accumulated water was removed, sun exposure was allowed for 2-3 days, and pesticide was sprayed to sterilize and kill insects in the whole field. At the same time, the perimeter of the insect net should be tightly sealed to prevent insects from sneaking in and laying eggs. When the small arched shed is used for covering cultivation, the arched shed should be higher than the crops, so as to prevent the vegetable leaves from clinging to the insect-proof net, so as to prevent the yellow stripes outside the net from jumping first-class pests from eating the vegetable leaves and laying eggs on the vegetable leaves.
Appropriate pore size
Pay attention to the aperture when buying insect nets. In vegetable production, it is advisable to use 20-32 mesh with a width of 1-1.8 meters. Black insect net can be selected.
Supporting measures
In insect net covering cultivation, decomposed pollution-free organic fertilizer should be added, heat-resistant and pest-resistant improved varieties, biological pesticides and pollution-free water sources should be selected, and micro-spray technology and other comprehensive measures should be adopted to produce pollution-free high-quality vegetables.
Careful custody
After the insect net is used in the field, it should be collected in time, washed, dried and rolled up to prolong its service life, reduce depreciation cost and increase economic benefits.
Insect net technology
Insect net is a new type of agricultural covering material. It uses high-quality polyethylene as raw material, adds chemical additives such as anti-aging, anti-ultraviolet and the like, and is formed by wire drawing and weaving. It looks like a window screen. It has the characteristics of tensile resistance, heat resistance, water resistance, corrosion resistance, innocuity and tastelessness, etc. It is portable to store and has a correct storage life of about 3-5 years. Apart from the advantages of sunshade nets, insect nets for vegetables are characterized by being able to prevent insects and diseases and greatly reduce pesticide usage. They are the key technologies for pollution-free vegetables and are simple, scientific and effective insect prevention measures.
Prevention principle
The insect-proof net uses artificial barriers to keep insects out of the net, so as to prevent insects, diseases and vegetables. In addition, the reflected and refracted light of the insect-proof net has certain repelling effect on pests.
1.The function of the insect-proof net
①Insect-proof: After vegetables are covered with the insect-proof net, the insect pests such as cabbage caterpillar, diamondback moth, cabbage moth, prodenia litura, yellow croaker beetle, ape leaf worm, aphid, etc. can be basically eliminated. According to experiments, the control effect of the insect net on cabbage caterpillar, diamondback moth, cowpea pod borer and Liriomyza sativae is 94-97%, and the control effect on aphids is 90%.
②Disease prevention: Viral diseases are catastrophic diseases on various vegetables, mainly transmitted by insects, especially aphids. As the insect net cuts off the main transmission route of pests, the infection of vegetable viruses is greatly reduced, and the control effect is about 80%. ③Adjust the temperature, soil temperature and humidity: The test shows that in the hot July to August, the temperature in the morning and evening is the same as that in the open air in the 25-mesh white insect-proof net, while it is about 1℃ lower than that in the open air at noon in sunny days. From March to April in early spring, the temperature in the insect net covered shed is 1-2℃ higher than that in the open field, and the ground temperature of 5 cm is 0.5-1℃ higher than that in the open field, which can effectively prevent frost. The rain in the insect-proof net room can reduce the precipitation in the net room, and the evaporation in the net room can be reduced in sunny days.
Shading strong light: strong light in summer can inhibit the vegetative growth of vegetable crops, especially leafy vegetables, and insect-proof nets can play a certain role in shading and preventing direct glare. Generally, the shading rate of 20-22 mesh silver-gray insect-proof nets is 20-25%.
2．Three, mesh selection
Three, mesh when choosing to buy insect nets should pay attention to the aperture. In vegetable production, it is advisable to use 20-32 mesh with a width of 1-1.8 meters.
3. Use of insect-proof net
① Greenhouse covering: The insect-proof net is directly covered on the large scaffolding, and the surroundings are tightly compacted with earth or brick. The roof pressure line should be tightened to prevent strong summer wind from lifting. Leave the front door uncovered for easy access. In and out at ordinary times, close the door behind you to prevent flying butterfly moths from laying eggs in the shed. At the same time, it is also necessary to regularly check whether there is a tear in the insect-proof net (especially if it has a long service life). Once found, it should be repaired in time to ensure that there is no pest invasion in the net room.
② Small arch shed covering: bamboo sheets or steel bars are bent into an arch shed to be inserted on the surface of the field border, insect-proof nets are covered on the arch frame, and then watering is directly carried out on the nets, and the nets are not uncovered until harvesting, and totally closed covering is carried out.
According to statistics of relevant UN organizations, 750,000 people worldwide are poisoned by pesticides every year, of which nearly 20,000 people are killed. In recent years, according to statistics from the Ministry of Agriculture and the Ministry of Health, the number of pesticide poisoning cases each year exceeds 100,000. All these poisoning are mostly food poisoning caused by pesticide residues in vegetables! This is how shocking. From the seriousness of pesticide pollution in vegetables, we see the urgency of promoting the use of insect nets.
Application range
(1) leafy vegetables are covered with insect-proof nets. leafy vegetables are the favorite vegetables for urban and rural residents in summer and autumn. they have the characteristics of fast growth and short cycle. however, there are many insect pests produced in the open field, and pesticide pollution is serious. citizens dare not eat them. Using insect net to cover cultivation can greatly reduce pesticide pollution. (2) cover cultivation of eggplant and melon with insect-proof net. Solanum melongena and melons are prone to viral diseases in summer and autumn. The application of insect-proof nets has cut off the transmission route of aphids and reduced the harm of viral diseases. (3) Nursery seedlings. Every year from June to August is the growing season for vegetables in autumn and winter. It is also a period of high humidity, heavy rain and frequent insect pests, which makes it difficult to grow seedlings. After using insect net, the vegetable has high emergence rate, high seedling rate and good seedling quality, thus winning the initiative in autumn and winter vegetable production.
Application effect
(1) economic benefits. Covering with insect-proof net can realize vegetable production without or with less medicine, thus saving medicine, labor and cost. Although the production cost is increased by using the insect-proof net, the insect-proof net has long service life (4-6 years), long service time (5-10 months) in the year and can be used in multiple crops (6-8 crops can be produced by planting leafy vegetables), and the input cost for each crop is low (the effect is more obvious in disaster years). Vegetables have good quality (no or less pesticide pollution) and good yield increasing effect. (2) social benefits. The social effect is self-evident. (3) Ecological benefits. Environmental problems have attracted more and more attention. Chemical pesticides have remarkable control effect, but they have exposed many disadvantages. The frequent use of pesticides has resulted in the pollution of soil, water and vegetables. Poisoning incidents occur from time to time every year due to eating vegetables contaminated by pesticides by mistake. Insects' drug resistance has increased and the control is becoming more and more difficult. Plutella xylostella, Spodoptera litura and other pests have even developed to the point where there is no drug to control. And insect-resistant covering cultivation is to achieve the purpose of insect prevention through physical control.