Winter temperatures are lower and may face icy weather. To prevent adverse effects of low temperatures on vegetable growers and to increase vegetable yield and quality, attention should be paid to greenhouse vegetable management. Let's discuss the key points for greenhouse vegetable management in winter.
Key Points for Greenhouse Vegetable Management in Winter
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Timely Fertilization: During the low-temperature period, the root activity decreases, excessive application of chemical fertilizers during fertilization can easily lead to root damage and yellowing leaves. Organic fertilizers or biological bacterial fertilizers should be primarily used for fertilization, but excessive fertilization should be avoided, following the principle of "little and often". Generally, apply organic fertilizers or biological bacterial fertilizers at a rate of 15-20 kg/acre per time.
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Foliar Nutrition: During low temperatures, root activity is weak, and foliar fertilization is a good way to supplement plant nutrition and prevent nutrient deficiencies. Common foliar fertilizers include comprehensive nutrients such as the Green Fenwei series, Fragrant Moisturizing foliar fertilizer, and Multi-force. When plants show signs of nutrient deficiency, corresponding foliar fertilizers can be sprayed to alleviate the deficiency.
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Water Control: Water should be controlled but not withheld. During temperature drops, farmers often hesitate to water for fear of root damage or increased humidity leading to disease after watering. However, vegetables in the fruiting stage require more water and nutrients. It is recommended that farmers choose sunny weather to replenish water for vegetables based on soil moisture conditions, using methods such as subsurface drip irrigation or light watering.
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Application of Plant Growth Regulators: Spraying plant growth regulators such as gibberellins, IAA, and chitosan can regulate crop growth and enhance plant disease resistance and stress tolerance. Gibberellin at a concentration of 1500 times or IAA at a concentration of 6000 times can be sprayed on weak plants. For excessively vigorous plants, spraying 25% chitosan at a concentration of 750-1500 times is recommended.
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Insulation and Ventilation: External temperatures are low in winter, and sometimes sunlight conditions are poor. To ensure greenhouse temperature, many farmers are reluctant to ventilate. However, ventilation is necessary to replenish carbon dioxide in the greenhouse, promote photosynthesis, and expel harmful gases accumulated in the greenhouse. Ventilation should be conducted without lowering the temperature. The duration of ventilation depends on the temperature inside the greenhouse.
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Enhanced Disease and Pest Control: In winter, due to the relatively sealed environment and high humidity in the greenhouse, vegetables' resistance to diseases and pests weakens, making it the most susceptible time for disease and pest breeding. Therefore, effective prevention of diseases and pests is crucial, which can be achieved using methods such as insect-proof nets and light-induced killing. If spraying is necessary, it should be done in the morning, and fumigation can be performed with smoke in the afternoon or at night.
Above are the key points for managing greenhouse vegetables in winter. To minimize frost damage to crops in the greenhouse, efforts should be made to enhance insulation, water control, fertilization, and other management practices.
