How to manage greenhouse vegetables in winter? Practical tips to share

1. When severe cold hits, the following measures can be taken: multi-layer covering, either by building a smaller shed inside the greenhouse or by laying another layer of film over the straw mats, to increase the insulation effect; digging cold-proof trenches outside the greenhouse in advance can raise the temperature inside the greenhouse by 2-3°C.

2. If there is continuous overcast weather, the straw curtains can be uncovered as long as the temperature is not too low. Hanging reflective screens on the back wall inside the greenhouse will also help increase light and raise the temperature on overcast days. To raise the ground temperature, plastic film should be laid early when there are many overcast days in winter, which can reduce the occurrence of low-temperature freeze damage. In winter, the temperature inside the greenhouse should be kept above 12°C; when the temperature is too low, warming measures can be taken.

3. In snowy weather, the straw curtains do not need to be covered when it snows during the day, and the snow on the greenhouse should be swept away immediately after the snow stops. To strengthen insulation, after covering the curtains in the afternoon, lay another layer of film over the straw curtains. If it snows at night, sweep away the snow promptly after it stops the next day so as to keep the straw curtains dry. When the weather suddenly clears after continuous overcast and snowy days, the curtains should first be pulled open at intervals or pulled open one third of the way, while watching for changes in the seedlings; if wilting is found, immediately cover the straw curtains again, and pull them open again after the plants recover, to prevent "flash shedding".

4. Remedial measures after freezing. After freezing, the temperature inside the greenhouse should be raised slowly, and the greenhouse must not be closed immediately to raise the temperature, so as to avoid necrosis of the vegetable tissues caused by a sudden rise in temperature. Frozen fruits, stems and leaves should be cut off promptly to prevent the tissues from becoming moldy and diseased.

5. Carry out routine management well. Uncover and cover the coverings at the right times. When about 70% of the seedlings have emerged, the covering should be removed promptly so that the seedlings gradually receive light. At night, the covering should be put back on to prevent the seedlings from freezing.

6. Ventilate at the right times to reduce humidity. As the temperature inside the seedling bed and the outside air temperature rise, the amount of ventilation needs to be increased to control the humidity inside the seedling facility.

7. Prevent seedlings from growing leggy. Chlormequat can be sprayed to suppress this; chlormequat can also enhance the disease resistance and cold resistance of the seedlings, but a high concentration can easily cause the vegetable seedlings to age.

8. Strengthen temperature and light management. In terms of light management, covering materials with good insulation and light transmission should be chosen for the facility as far as possible, and multi-functional composite film is recommended.

9. In terms of temperature management, appropriate regulation should be carried out according to the different temperature requirements of different vegetables at different growth stages. In winter, the cold-proof and insulation work of the facility should be done well to avoid the adverse effects of sudden temperature drops on seedling raising and vegetables.

10. Prevent and control pests and diseases in time. During the seedling growth process, vegetables are prone to damping-off, Rhizoctonia rot and gray mold. In disease control, a prevention-first strategy should be adopted. It is recommended to carry out one chemical control treatment per week; on overcast and rainy days, smoke agents are recommended instead of spray control.