Recently, the temperature has gradually dropped, and there may be a cold wave at any time. Such weather often causes freezing damage in greenhouse vegetables. In order to minimize losses, farmers’ friends should manage the management of greenhouse vegetables from the following three aspects:
First, strengthen the greenhouse before the cold wave
Rain and snow, even cloudy days and cold waves are the three major meteorological disasters in winter greenhouses. They can cause plastic greenhouses to be devastated. Therefore, farmers should pay attention to early prevention measures.
1. Always check the tightness of the lamination line. The southern end of the laminating line is fixed on the ground anchor, and a sandbag is tied at the north end to poke outside the north wall. The lamination line can be adjusted at any time, and the windproof effect is good.
2. Repair the greenhouse film. Use a transparent tape to repair the damaged part of the shed film at any time to prevent strong wind from blowing in and damaging the shed film.
3. Prepare relevant materials. Prepare a certain number of sandbags with a length of 10 cm and a length of about 1 m, and place them on the back slope. When the wind blown film oscillates up and down, it is pressed on the shed film in time, which has a good windproof effect.
2. Strengthening the timely management of greenhouses during the cold wave
1. Light transmission. In the absence of light during the rainy and snowy days, some grasshoppers must be uncovered to allow for scattered light, and the vegetable can still carry out weak photosynthesis to maintain the slow growth and development needs. Don't expose the scorpion all day long, let the leeks spend the day in the dark, which is very unfavorable for the growth of the leeks, and it is easy to cause various diseases. If you don’t reveal the scorpion for more than two days, it will cause the wilting and death of the vegetable seedlings.
2. Uncover the timely removal of the pampas grass. If the temperature is not too low during the rainy days, if it starts to snow or rain during the day, immediately lift the pampas grass and clean the snow on the shed film after stopping the snow; if it snows at night, after sweeping the snow in the morning It is also necessary to immediately uncover the sputum; if it is snowing and raining for several days, it will be cleaned continuously, and only a half-baked or half-baked flower buds will be uncovered. There are consecutive cloudy days for more than two days. After the sunny day, you can't uncover all the grasshoppers at once, to prevent the thin and weak seedlings of the rigid weather from catching the glare, and the temperature in the shed suddenly increases, so that the seedlings can increase the evaporation of water. The soil temperature is low, and the roots absorb water very slowly, causing water imbalance in the body and temporary wilting. At this time, some grasshoppers should be put down as soon as possible to cool down. After the vegetables are restored to growth, they will be uncovered. After two or three times, the rapeseed can grow normally. Otherwise, the temporary wilting will become permanent wilting and death, which is one of the important reasons for the failure of some shed production. During this period, you can't leave people in the shed every day. You should uncover the flowers or expose them at any time, that is, uncover the cover and cover it until the plants or seedlings return to normal.
3. Guarantee the low temperature limit in the shed. The temperature in the rain and snow canopy does not need to be warmed as long as it is above the minimum limit. For vegetable varieties of solanaceous fruits, melons or beans, the minimum limit required for temperature in the greenhouse during seedling and growth period is not less than 5 °C. The lowest temperature is not lower than 10 °C; the light intensity of the greenhouse is not less than 50Klux. Therefore, in the management of severe weather, the warm light should be done according to the above minimum standards, so that the rapeseed can pass the severe weather at low temperature and reduce The nutrient consumption in the body is conducive to the recovery and growth after the sunny day. Otherwise, bad results will occur.
3. Measures to be taken after the cold wave affects the shed vegetables
1. Cut off the frozen stems and leaves and increase the temperature of the shed.
1 Cut off the injured stems and leaves to avoid mildew lesions and induce disease.
2 increase the temperature of the greenhouse. The first is a temporary stove or brazier in the greenhouse, but there must be a chimney to prevent CO poisoning in the plant body, and the leaves of the frozen plant are thin or wilting. The chamber temperature can be increased from 3 ° C to 5 ° C. Second, there is a power shed: the hotline is laid on both sides of each ditch to increase the ground temperature and the shed temperature; the hot air is used to heat the indoor air; the indoor typhoon is hung in the shed; the 200 watt large bulb or 40 watt is used. Fluorescent tube; discharge hot gas, etc. The chamber temperature can be increased from 5 ° C to 7 ° C. The third is to add a layer of pampas grass in the front window outside the greenhouse; use the 8th wire as the support frame in the greenhouse, and then cover the film; if the plant is planted soon or the seedbed is planted, it can be placed on it. Small for the shed, forming a double-layer cover, can also be covered with a heat preservation curtain on the Pu-Erh. This measure can increase the room temperature from 3 ° C to 5 ° C. However, during the heating process, attention should be paid to slowly increasing the temperature of the shed, so that the frozen tissue can fully absorb water and promote cell reactivation. Can not immediately close the shed to heat up, if the temperature rises too fast, the frozen tissue will dehydrate and die. Scaffolding in the shed prevents the frozen vegetables from losing water due to direct sunlight.
2. Watering in time to increase soil heat capacity. Watering can increase the soil heat capacity, stabilize the surface air temperature in the shed and the shed, inhibit the temperature drop, and effectively reduce and control the development of frost damage. The key to water management is to coordinate the relationship between watering and increasing the ground temperature and reducing the humidity in the shed. It is necessary to ensure the normal demand of soil moisture and nutrients for vegetables, and to maintain a suitable soil temperature, and to minimize the humidity in the shed. Watering should be "three attentions." First, pay attention to watering on sunny days, and ensure that there is at least 2 days of sunny weather after watering. It should be watered in the morning. It should not be carried out at noon or afternoon. Therefore, the water temperature is close to the ground temperature and will not greatly reduce the ground temperature. At the same time, it is advisable to use underground well water for watering. The temperature of the well water is generally around 14 °C, which is good for maintaining the high ground temperature of the greenhouse, and the water flow is not too long. Second, pay attention to the watering method. When watering, not only the water requirement of vegetables should be considered, but also the humidity of the greenhouse should be considered. Therefore, it is advisable to use watering under the membrane for watering, and to cast small ditch and water. Third, we must pay attention to post-watering management. On the day of watering, in order to restore the ground temperature as soon as possible, it is generally necessary to close the greenhouse to rapidly increase the indoor temperature. After the ground temperature is raised, the air is released in time to reduce the temperature to a suitable range. Such as cucumber, after the watering, the greenhouse is warmed up, and the temperature in the shed can reach 33 °C, then the wind will be released, and the next day will continue to close the shed to raise the ground temperature.
3. Chasing quick-acting fertilizer. Appropriate amount of quick-acting fertilizer can be applied to the frozen plants combined with watering, which can improve the nutritional status of the crops, enhance the cold and frost resistance of the plants, and promote the early growth of the plants. Foliar spraying is more economical and quicker than soil application, and should be sprayed according to the characteristics of fertilizers of different crops. It is better to add an appropriate amount of gibberellin when spraying foliar fertilizer.
4. Spray some protective agents and anti-disease agents in time. After the plants are frozen, the pests and diseases are easily taken in. The protective agents, anti-disease and insect-repellent agents should be sprayed in time, and the frozen stems and leaves should be cut off in time to avoid moldy diseases and induce diseases. Optional protective pest control agents, such as 80% complex state mancozebium 500 times solution, 50% pupacean 1000 times solution, 64% imported antivirus 矾 500 times solution, 50% Nong Liling 500 times solution, etc. .
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