How to remedy the facility vegetables in bad weather such as heavy rain and blizzard?
It is expected that in the next three days, due to the influence of cold air, the central and eastern regions will usher in a windy and cool weather. The majority of the area north of the Yangtze River will cool down by 6-8 °C, and the local temperature will drop by more than 10 °C. The cooling will inevitably bring about a reduction in production or even a decline in vegetable production. Therefore, the vegetable farmers should do a good job in anti-freezing measures in greenhouse vegetables and master the methods of remediation after freezing.
1The effect of low temperature on the growth and development of vegetables
1.1 Seedling growth dysplasia
The cotyledon stage of the seedlings is damaged by low temperature, and the chlorosis of the cotyledon leaves has a white edge. The seedlings of cucumber seedlings are pale, and there are small old seedlings or a large number of dead seedlings; the true leaves are weak and white spots appear after freezing, the leaf edge water loss turns yellowish white, the veins remain green at the beginning, the unaffected parts can continue to grow, and the severely diseased seedlings gradually Dry out. Seedlings that are affected by low temperature do not slow down or slow down the seedlings and affect the yield and time to market.
1.2 Seedling stage low temperature disease
When the seedling stage encounters low temperature, especially low ground temperature, it is prone to physiological roots and no new roots for a long time. There are few or no roots, and some of the old roots are yellow and rust brown. At the beginning of the roots, the leaves of the seedlings became thinner. After the sun was irradiated, the leaves were wilted and the leaves were dried up. The whole plant died and the diseased seedlings were easily pulled out from the soil. At the same time, when the seedlings encounter low temperature, it is easy to induce seedling diseases such as rickets, blight, and diseases. When the temperature is more severe, the growth point of the plant is frozen, and the young part of the top is water-stained, and then the water loses and sag and forms a bald tip.
1.3 adult stage low temperature damage
In the adult stage of vegetables, if the temperature is dysfunctional, the leaves are distorted and irregular white spots or pale brown leaves are dry on the leaves; the flowering results show the topping, falling flowers, deformed fruits, dead plants, etc. Symptoms reduce the value of the commodity, seriously affecting production and even production.
2 Precautions for freezing rain and snow disasters
2.1 Pay attention to check or listen to the weather forecast
Vegetable farmers can go online to find weather information for the next few days in the country, or use a smart phone to check the latest weather information, including the weather forecast for the next 72 hours and a week, the latest weather disaster warning information.
2.2 Reinforce and seal the facility in advance
According to the weather conditions of freezing rain and snow disasters that have occurred over the years, the facilities will be strengthened in time, and the areas where the greenhouses are easy to loosen will be carefully inspected, the tightness of the laminating lines will be adjusted, and the damaged parts of the agricultural film will be repaired in time to avoid air leakage.
2.3 Select the film with better light transmission and heat preservation effect
Multi-functional membranes with good light transmission and heat preservation effect, such as no drip film, EVA (ethylene-vinyl acetate copolymer) film, diffuse reflection film, etc., are selected.
2.4 multi-layer coverage
In the event of freezing rain and snow disasters, multiple layers of coverage are provided in the greenhouse in time, such as erection of medium sheds and small arch sheds, combined with film covering night covering straw curtains, paper quilts, sacks, non-woven fabrics, sunshade nets, etc. The warm vegetables of solanaceous fruits and melons should cover more than 3 layers, sealing vents and inner sheds.
2.5 increase the geothermal storage in the greenhouse
Cover the mulch film and small arch shed early, add organic fertilizer and bacterial fertilizer, cover the corn stalk, chaff and sawdust on the walkway in the shed, and choose the sunny weather to pour the anti-freezing water before cooling, and reduce the air humidity in the shed to increase the temperature and keep warm.
2.6 Clear snow in time
The next morning after the snow, try to remove the snow from the shed and the surrounding area, so that the shed can receive light as much as possible, and if necessary, add support columns in the shed. Immediately after the snow, clear the ditch to eliminate snow and water, and prevent the heat from being absorbed by the large amount of heat when the snow and ice melt.
2.7 supplementary heating
When the low-temperature cold-flow weather comes, if the temperature condition is still not met by the multi-layer coverage, the light can be lighted up at night, the electric heating line or the coal briquettes can be supplemented.
2.8 select varieties with strong resistance
Winter and spring facility vegetable production, variety selection is very important, especially for warm fruits and vegetables, should pay attention to choose cold, cold, low temperature and low light, more resistant to moisture.
2.9 Correct determination of sowing date and planting period
According to different types of vegetables, different varieties, local climatic characteristics, thermal insulation performance of facilities, etc., it is not allowed to blindly determine the sowing date and the planting period. Planting and planting should choose a windless sunny day with a cold head.
2.10 seedling stage for low temperature exercise
Seeds that have not been exposed to the seed coat after germination, placed at a low temperature of -2 °C for 2 to 5 h, taken out slowly and thawed and then re-germinated, which can make the sprouting strong and cold-resistant; Temperature, using large temperature difference management to prevent the length of the seedlings, improve the resistance of the seedlings; seedlings and 2 days before planting, strengthen ventilation and low temperature refining.
2.11 reasonable topdressing
Before the advent of cold wave, pay attention to reduce the amount of nitrogen fertilizer to avoid plant growth. If necessary, foliar spray 0.3% potassium dihydrogen phosphate solution, compound brown sugar 150 times solution, spray 2~3 times or spray anti-cold agent 1~2 times. .
2.12 Reasonable watering
It is best to use drip irrigation under the membrane and seepage irrigation to prevent the ground temperature from falling due to watering.
3 Remedial measures after the freezing rain and snow disaster
3.1 Remedy for mild victimization
There are only sporadic macula, and the rest of the plants are in good condition. The following measures can be taken when the degree of damage is light.
1 foliar spray
For mildly frost-damaged plants, foliar sprayed rice vinegar 300 times + glucose powder 150 times + chitin 500 times solution, 0.2% potassium dihydrogen phosphate solution can also be added to supplement nutrients, increase leaf sugar content, increase leaf hardness, increase resistance Cold; can also spray plant cold resistance to enhance plant resistance. Note that foliar application should be done with warm water as much as possible. Do not use auxin hormones to prevent cold resistance.
2 timely ventilation
After the weather turns fine, the cover in the greenhouse will be removed in time, and the gas in the lee of the greenhouse will be ventilated to remove harmful gases. In the rainy weather, the opaque coverings in the greenhouse should also be uncovered in time, and ventilation should be ventilated around noon to eliminate harmful gases in the shed.
3 to prevent "flash seedlings" from wilting
After continuous rainy or snowy weather, it will suddenly turn fine. When ventilation, gradually increase the ventilation from small to large to prevent the plant from suddenly seeing light and appear wilting. If it is found to be wilting, it should be covered with paper, shade net, non-woven fabric, etc. Spray water properly, re-open after recovery, and repeatedly cover, after 2 to 3 days, you can transfer to normal management.
4 strengthen pest control
Low temperature, high humidity and low light conditions are easy to cause low temperature diseases such as gray mold and disease. In the field management, attention should be paid to reduce the humidity in the shed, and timely use chlorothalonil or procymidone to prevent and control the pests and diseases.
3.2 Moderately victimized remedies
Some of the leaves are dry and dry or the leaves are dry yellow. Most of the leaves and growth points are intact, and the heart leaves can grow quickly. It is moderately damaged. The following measures can be taken.
1 slowly seeing light
After the disaster, the frozen vegetables can not be directly exposed to direct sunlight. They can be covered with a small shed film in the shed indoors with a sunshade net, non-woven fabric or newspaper. They can also be directly covered on the frozen vegetables to make the frozen vegetables slowly thaw. Restore growth.
2 slowly warming up
After the weather is fine, you should not use the measures of rapid temperature rise to thaw. In addition to shading, you can also take appropriate measures such as releasing air to make the shed temperature rise slowly.
3 application of disease prevention
The growth of vegetables after freezing is weak and prone to diseases such as gray mold. After the vegetables are restored to growth, the frozen part can be cut off, and the diseased, yellow, and old leaves can be removed to avoid the disease caused by the mildew of the frozen tissue, and smoked with 10% keeling (Pythium).
Vegetable farmers should always pay attention to the weather forecast, and prevent frost damage in time before the coming of the heavy rainstorm to avoid the loss caused by bad weather.
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