The winter and spring protected areas provide people with a large number of off-season vegetables, which enrich the market and satisfy people's demand for fresh vegetables in winter and spring. However, with the increase of planting area in protected areas and the increase of vegetable varieties, there are more and more species of pests and diseases of vegetables in protected areas, and the area of ​​occurrence has been increasing year by year. The loss of damage has become increasingly serious and has become an important factor affecting the production of vegetables in protected areas. At present, people are paying more and more attention to the quality and safety of vegetables. Not only do they require a wide variety of products, but they also pay special attention to the appearance and pesticide residues of vegetables. Therefore, in the prevention and control of pests and diseases of vegetables in protected areas in winter and spring, it must be carried out in accordance with the standards for the production of pollution-free agricultural products. It is truly “prevention-oriented, comprehensive prevention and controlâ€, and comprehensive use of agricultural, ecological, physical and chemical control methods, etc. Control the hazards of pests and diseases of vegetables in protected areas. First, agricultural control technology Timely gardening, sun drying and soil disinfection. Before planting vegetables in winter, clean the plant residues and weeds in the protected area, eliminate the germs and eggs on the litter and weeds, and eliminate the wintering eggs in the soil through sun exposure. Doing a good job of disinfecting the soil in protected areas can kill pathogens, pests, and other harmful organisms in the soil, and can effectively control pests and diseases. The main methods are sunlight high temperature disinfection, steam disinfection and methyl bromide fumigation. 2. Use pest-resistant vegetable varieties as much as possible. Select high-resistant or multi-resistant varieties, such as the tomato variety Shuangkang No. 2 can be resistant to leaf mold, hair powder 802 can be resistant to aphids, cucumber strains are more resistant to powdery mildew Jin Yan No. 2, No. 4 and No. 6, Tianjin Spring 4 can be resistant to blight, downy mildew and powdery mildew. Among the eggplant varieties, the Beijing line of eggplant and bovine heartworm were more resistant to Brownie disease, while the purple circle eggplant and Beijing nine-leaf eggplant were more resistant to cotton blight. 3. Scientific and rational farming system. For example, a comprehensive system of land use and land conservation should be adopted, and a reasonable rotation, intercropping and intercropping should be adopted. Long-term continuous cropping will lead to autotoxicity of crops, such as cucumbers, peas, soybeans, and tomatoes, which have a strong autotoxicity effect. Generally, continuous cropping can cause soil-borne diseases to increase. When rotations are carried out, crop rotations of the same family and genus are prohibited, and the relationship between land use and land conservation is coordinated. Garlic and onion root exudates have a bactericidal effect, and they can be planted with shallots and garlic during the leisure period. In addition, the reasonable adjustment of sowing date or transplanting period of vegetables can avoid the peak of pests and diseases to reduce the harm of pests and diseases. Tomatoes and Chinese cabbage avoid high temperatures during seedlings, which can reduce viral diseases. 4. Cultivate strong seedlings to reduce pests and diseases. The measures taken are: 1 Seedlings in different places or places. 2 mulching seedlings can be used nutrition pods, plugs, nutrition soil seedlings and so on. Strengthen the seedling management, improve the ability of disease-resistant and insect-resistant seedlings, eliminate weak seedlings when transplanting, and ensure strong seedling colonization. 5. Promote grafting and disease prevention technology. For diseases such as melon wilt and eggplant verticillium wilt, which are difficult to prevent in winter and spring protected areas, grafting can be used to control diseases. Grafting seedlings is mainly to prevent soil-borne diseases, enhance the growth of plants, and improve the ability to resist cold and drought. Grafting should take into account the affinity of the rootstock and scion, the resistance of the root system, the high yield and adaptability of the variety. For example, pumpkins are used as rootstocks for grafting cucumbers, and tomatoes are used as rootstocks for grafting of eggplants. Grafting methods can achieve good results by using grafting and inserting. Second, regulate and control the environment of the facility reasonably, and use the protection temperature and humidity control technology to prevent and control pests and diseases. Protected soil temperature and humidity and air humidity control. Using the special environment of the protected area, measures such as releasing air and closing sheds are used to regulate temperature and humidity. Covering the film and enhancing ventilation can increase soil moisture and reduce air humidity. With adequate lighting, ventilation, ventilation and other measures to learn, do not fight drugs or fight drugs can control a variety of diseases. Such as high-temperature sterilization and antibacterial, cucumber shed temperature management, control of downy mildew and so on. 2. Gas control in protected areas. When there is a shortage of organic fertilizer in protected areas, carbon dioxide fertilizer can be applied. The crop needs to have a carbon dioxide concentration of 80010-6 to 100010-6. Therefore, when the temperature is high at noon, vents should be opened to allow air to circulate, and toxic gases such as ammonia, ethylene, and sulfur dioxide in the protected area should be released to prevent the vegetables from being harmed by the air. 3. The regulation of light. According to the different stages of crop growth, timely light exposure control. Third, physical control technology 1. The use of temperature such as soaking seeds, high temperature soil disinfection and other measures. Such as the use of 50-55 °C warm water soaking seeds 10-20 minutes, can kill the bacteria attached to the seed surface. For the prevention and control of tomato early blight, eggplant brown streaks can be soaked with 0.3% potassium permanganate solution for 20-30 minutes or soaked for 20-30 minutes with a 600-fold solution of the bacterium, remove and wash with warm water 5-6 times. 2. According to pests, they have special tactics to trap and kill pests. Such as the use of yellow traps to kill whitefly, spotted fly and aphids. 3. Manually kill. In the field of agricultural operations, eggs and newly hatched larvae produced by pests on vegetables should be promptly removed. IV. Chemical prevention and control technology At present, how to use pesticides safely and reasonably in the prevention and control of vegetable pests and diseases in protected fields is particularly important. The use of chemical pesticides in protected areas in winter and spring should pay attention to the following points: It is forbidden to use highly toxic and highly toxic high residue pesticides on vegetables. Such as methamidophos, methyl parathion, parathion, monocrotophos, phosphine and so on. 2. According to the occurrence of pests and diseases in protected areas, as little as possible or no medication. That is, the use of drugs also use low-toxic, low-residue chemical pesticides or biological pesticides to achieve the purpose of reducing pollution or pollution. In addition, it is necessary to control the number of medications and master the medication time. For example, thiophanate, which is commonly used in the control of gray mold, powdery mildew, anthrax, and chlorothalonil, which controls rust, downy mildew and leaf spot, does not exceed the maximum number of medications during the entire growth period. 3 times, the last time the medicine is used should be harvested for not less than 15 days. For pesticides such as trichlorfon, phoxim, and deltamethrin, which are used to control pests, the maximum number of pesticides used during the whole growth period should not exceed 3 times. The last time the pesticide is used should be no less than 7 days from the harvest. 3. Master scientific pesticide application technology. Correctly grasp the dosage and concentration of pesticides, pay attention to alternating use of drugs. 4. Biological pesticides commonly used in pest control of protected vegetables. There are efford, vegetable, 1% imidacloprid, Bacillus thuringiensis (Bt) preparations, 1000, 1.5% Sudan WP 750, 1000 times; 0.9% avermectin EC 3000 times, Huanye 3 WP 250, 500 times and so on.
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