How do early spring vegetables prevent the hazards of early spring cold?
cold spring is a weather phenomenon in which the temperature in early spring is lower than that of the same period in normal years, and crops often suffer from freezing damage due to this.
spring cold is more harmful to spring vegetables, from the slightest it causes growth retardation, frostbite of the seedlings, and severely causes the vegetables to fall flowers, fruit, rotten roots and even die. The phenomenon of seedlings.
Vegetable insulation and antifreeze management measures before the arrival of spring cold
1, soil insulation
Before the arrival of the cold spring, cultivating the vegetables in the soil, so that the soil can absorb and store more solar heat.
2, reasonable top-dressing
Before the arrival of the cold weather in spring, ①add as much thermal fertilizer as decomposed pig manure, cow manure, compost, etc.; ②spray 1-2 times as needed 0.3%potassium dihydrogen phosphate and plant growth regulators, boron, zinc, magnesium and other trace element foliar fertilizers can also be sprayed with thin human feces and urine.
3, scientific watering
Avoid irrigating a lot of cold water during the low temperature period before the arrival of the cold spring to prevent further lowering the ground temperature and inducing more severe freezing damage. When the soil temperature drops below 0°C, in the morning on a sunny day, use a lot of well water with a higher temperature to irrigate the field.
4. Spray antifreeze
antifreeze is mainly used to adjust the cell sap concentration, or some reagents that activate the gene expression of the antifreeze mechanism through external chemical substances. Plants that have been frost-damaged can also quickly restore normal growth.
5. Overhaul coverage
Before the cold spring comes, repair or replace the damaged part of the greenhouse in advance. Plastic film, straw curtains, heat preservation quilts, etc. can be used for multi-layer cover and heat preservation protection, and small and medium arch sheds can also be temporarily built in the shed, which can well reduce the low temperature hazards of vegetables.
6. Temporary temperature increase
In the greenhouse, temporary heating facilities such as coal stoves, hot blast stoves, heating wires, electric heaters, etc. are installed to temporarily increase the temperature and increase the indoor temperature of the shed. So as to prevent the occurrence of low-temperature freezing damage to vegetables.
7, smoke to drive cold
frost night, smoking in the field can effectively reduce or avoid frost disaster.
8, increase light
thoroughly clean the dust and debris on the canopy film in advance, and hang a reflective screen on the back wall of the canopy. If you encounter continuous cloud and cooling weather, it is best to temporarily stay in the canopy. Add supplementary lights to maximize the amount of light in the shed and extend the lighting time of vegetables. In addition, timely and reasonable removal of old leaves, yellow leaves, and diseased leaves in the middle and lower parts.
9, low-temperature seedling cultivation
After the vegetable seedlings have been planted, the ventilation should be gradually increased for low-temperature refining, so as to promote the vegetable seedlings to adapt to low-temperature weather as soon as possible and to resist the external cold-freezing weather.
10. Avoid pruning
Avoid pruning and splitting vegetables when the cold weather occurs in late spring, to prevent aggravating bleeding, freezing damage, or causing pests and diseases to invade the seedlings through the wound.
11. Set up cold and wind barriers
There are often windy weather in late spring and cold spring. At the upwind position where cold air or cold currents invade, use straw braid or corn stalks to set up a 1.5-meter-high barrier. Wind wall, avoid cold wind blowing directly on the vegetable field or shed.
Emergency management measures for vegetables after the cold spring season
1. Strengthen the prevention and management of pests and diseases
spring cold, cold wave, rain and snow, etc., will reduce the resistance and disease resistance of vegetables (especially greenhouse vegetables), and easily induce late blight and gray mold. , Sclerotinia, downy mildew and other low-temperature and high-humidity diseases and insect pests are prevalent.
Therefore, after the cold spring, cold wave, rain and snow, we should strengthen the detection and prevention and control of low-temperature and high-humidity pests and diseases, and spray drugs in advance to prevent the occurrence of pests and diseases. Fumigant drugs or powder drugs should be selected first to prevent further increase of soil moisture in the field and aggravate diseases and insect pests or reduce the effect of disease and insect pest control.
2, arrange vegetable seedlings in time
timely cut off the dead branches of the stems and leaves that are severely frost-damaged, pull out the frozen seedlings, and thoroughly clean up the residual leaves of the diseased plants in the field. In order to prevent the diseased plant residues from mildewing in the field and inducing new pests and diseases.
3. Apply fertilizer and water in time to promote growth
Apply fertilizer and water in time, mention ground temperature, and supplement nutrients for vegetables to promote recovery.
4. Timely cultivating and loosening soil for soil protection
After the weather has cleared and warmed up, carry out shallow hoeing and middle plowing to loosen the soil in time to break the surface soil compaction, improve the looseness and permeability of the soil, and effectively increase the soil temperature and strengthen The respiration capacity of the root system creates a good soil environment for the recovery and growth of the root system.
5. Clear ditch and drain moisture in time to prevent waterlogging
Timely ditch clearing, snow removal, drainage and dehumidification, lowering the water level, to avoid accumulation of water on the ground and excessive soil humidity, which may further reduce the soil temperature or cause vegetable roots to occur Problems such as frostbite, retting and rotten roots.
6. Pay attention to cover to prevent direct sunlight, avoid premature ventilation and rapid heating
Vegetables suffering from freezing damage are prone to further dehydration and shrinkage of frozen tissues after the weather is clear, direct sunlight or premature ventilation, leading to freezing damage Vegetables withered and died rapidly.
Therefore, in the management of freeze-damaged vegetables (mainly greenhouse vegetables), the vegetables can be gradually increased by supplementing nutrients, cultivating soil loosening, and gradually increasing the area of curtains. Return to normal growth.
once again reminded the majority of growers to pay attention to the local weather forecast from February to April. Insulation and anti-freezing measures should be taken. On the other hand, remedial measures for frost damage of field crops should be done in time after the cold weather in late spring to minimize the damage caused by the cold in late spring.