2, water damage, in order to avoid and reduce water damage, it is necessary to transform the waterproof facilities of the old shed and make full and rational use of precious water resources. Water it if there is water. If there is no water, it will kill you. When the water is controlled, the water is controlled and the disease is not controlled; Water is the life and disease of vegetables; Use water scientifically and rationally, control watering time and amount, and consider seedling conditions, moisture content, weather conditions and warmth retention. Because vegetables are harvested or not harvested in water.
3. Heat damage, that is, high temperature damage, we should grasp the air inlet reasonably when heating up, and grasp the air outlet reasonably when cooling down. The most important thing is to hang the wet and dry thermometer on the growing point of vegetables. The measured relative temperature in the shed is more scientific. When the temperature in the shed is too high or the rainy and snowy weather suddenly clears up for a long time, the harm of high temperature should be reduced, or the shade shed should be used to shade the sun, and the ventilation volume should be increased to make the air circulate, reduce the harm and ventilate.
4. Freeze injury, improve the frame for strengthening the greenhouse and the pressing belt of the greenhouse film, choose high-quality thick straw mats and non-woven fabrics with good thermal insulation effect, cover them with polyethylene plastic film when cooling down, and pay attention to the weather forecast every night. Clean up the snow on the shed in time, strengthen the closed facilities at the door, set up workshops, set up defensive curtains 20 meters away from the door, and hang reflective curtains on the back walls of solar greenhouses and basements. More importantly, we should pay attention to the adaptation of various vegetables to low temperature, wait for the cooling situation, and avoid reducing freezing damage, which will kill us.
5. Gas hazard: chicken manure, pig manure, duck manure, human manure and human urine are not used or used less, and must be fully decomposed, aired and air-dried. Nitrate nitrogen fertilizer, pure nitrogen fertilizer and compound fertilizer, compound fertilizer and compound fertilizer with high nitrogen content are not needed. No smoking in the shed, frequent ventilation, expand the proportion of carbon dioxide entering the shed, reduce the amount of harmful gases such as ammonia, nitric oxide and nitrous acid, and rationally apply chemical fertilizers and pesticides to make the shed
6, phytotoxicity, scientific use of drugs, rational use of drugs, suit the remedy to the case, spraying the vegetables in the greenhouse at the air outlet, not spraying after 2 pm, strict pesticide compatibility, secondary dilution, no chemicals, less spraying, concentration control, no harmful pesticides, no highly toxic pesticides, no high residual pesticides, strict application methods, application time and concentration, especially herbicides. The left green should be carried out according to the new techniques of off-season cultivation and open field cultivation of various fruit vegetables in front of us. We should be careful not to use drugs blindly, minimize the harm of pesticides and maximize the control effect. If phytotoxicity is found, it should be abolished by spraying trace element fertilizer at the first time, so as to minimize economic losses and improve the economic benefits of vegetable planting.
7, diseases, greenhouse vegetable diseases, because of the relationship between protected areas, because of high temperature, because of high humidity, all have the characteristics of fast onset, fast infection and difficult prevention and control. These many diseases and countless pesticides make it very troublesome for vegetable farmers to choose. Therefore, in accordance with the spirit of "prevention first, comprehensive prevention" in the plant protection policy of the Ministry of Agriculture, it is better to treat diseases than to prevent them early. We divide hundreds of diseases into two kinds, one is physiological disease, the other is disseminated disease, and the physiological disease is element deficiency disease. It is the best way to supplement and adjust with the clear liquid fertilizer of total nutrients and trace elements we mentioned earlier. As for disseminated diseases, we can divide them into mycoses, bacterial diseases and viral diseases, so it is relatively simple to prevent and control them. When vegetable farmers don't know what disease it is, they can spray it on the leaves with efficient fungicides. When we can tell what diseases they are and don't know what medicine to use, we can also use such an efficient fungicide to prevent them. The disease is more serious, wider and more common. We can track the application of pesticides, and of course, we can also cooperate with special fungicides on the market for prevention and control. This method is simple, easy to learn and easy to remember. It does not waste money, buy drugs or beat drugs indiscriminately, which reduces public hazards, improves quality and achieves better results.
8. Pests. Greenhouse pests are generally divided into aboveground vegetable pests and underground pests. Therefore, for pollution-free vegetable products and pollution-free greenhouse environment, we can choose the best Bacillus pesticides or amide pesticides in recent years, such as plant pesticides and biological pesticides. Prevention and control in advance is better. Underground pests can be controlled by carbaryl and chlorpyrifos. Root-knot nematodes can be controlled by soil lines, lines and fronts. Choosing these low toxicity, high efficiency, no residue, no pollution and no pollution plant pesticides, biological pesticides and pollution-free pesticides has the advantages of good application effect, low labor intensity, less application times, mutual cooperation and high economic benefits, and is the first choice for greenhouse vegetable production.