Key Technical Points for the Production Management of Melons, Fruits and Vegetables Under High-Temperature Weather

Currently it is the high-temperature summer-autumn drought season, with the weather dominated by clear, hot, high temperatures and little rain. The output rate of melons, fruits and vegetables in the fields is greatly reduced. So how should the production management of melons, fruits and vegetables be done well under high-temperature days? Let's learn about it together below.

I. Strengthen the management of vegetables in the fields

The vegetables currently in the fields mainly include fast-growing leafy vegetables, loofah, cowpea and other heat-tolerant vegetables in the plains, as well as eggplant, cucumber, kidney bean, water bamboo and others in the mountains. First, shading measures should be adopted. In high-temperature weather, it is advocated to use protective measures such as covering with shade nets to block strong light, block strong ultraviolet rays and lower high temperatures, so as to prevent high temperatures from scorching leaves, reduce adverse effects, improve quality and extend the market availability period. Second, strengthen ventilation and cooling. Prune the lower old leaves to increase ventilation and achieve the purpose of disease prevention and cooling. Where conditions permit, adopt technical measures such as pruning for rejuvenation and re-flowering to avoid high temperatures, stagger the product marketing season, improve quality and increase benefits. Third, cover the bed surface and skillfully supplement fertilizer and water. According to the principle of applying thin fertilizer frequently, where conditions permit, use sprinkler and drip irrigation facilities to irrigate timely in the early morning and evening to supplement fertilizer and water.

II. Strengthen the management of sowing and seedling raising for autumn vegetables

Now is the key period for sowing autumn vegetables such as cauliflower, solanaceous vegetables and cucurbit vegetables. They should be sown at the appropriate time, with control as the main approach and combined promotion and control, to prevent excessive seedling growth and cultivate strong seedlings of the appropriate age. First, fully cover the seedbed land with shade nets and insect-proof nets to prevent seedling scorching and damage by pests. After about 30% emergence, the covering time can be gradually reduced according to the climate. For vegetable seeds with weak germination vigor such as lettuce and celery, shading materials can be covered on the bed surface and removed promptly after emergence. Second, try to keep the soil moist. In addition to watering every morning and evening, once every 3-5 days in the evening, irrigate once with running water. Where conditions permit, micro-sprinkler irrigation technology should be used for cooling and humidifying, and fans should be used to enhance ventilation and improve the growing environment for vegetable seedlings. Third, use plug trays and lightweight substrates with good water-holding capacity for seedling raising, pay attention to the amount of phosphorus and potassium fertilizer, and control the amount of nitrogen fertilizer to prevent excessive seedling growth and improve seedling quality.

III. Strengthen field management of vegetables during crop rotation

At present, it is the season for crop rotation of plain vegetables. First, promptly remove the residual plants of the previous crop. Clean up weeds at the edges of ditches, canals and roads, and take advantage of the favorable high-temperature weather to adopt soil disinfection treatment methods such as plowing and sun-drying the soil, flooding the field with water, and high-temperature greenhouse sealing (above 70°C inside the greenhouse), so as to reduce the base numbers of salt, diseases, pests and weeds in the soil and ensure the soil safety of the next crop of vegetable production. Second, for greenhouse asparagus, promptly clean up the aging spring mother stems at the appropriate time, remove weeds, and carry out pest and disease control. In the evening, run water to eliminate the underground larvae of tobacco cutworm and beet armyworm, reduce the residual population density, and carry out a comprehensive sterilization of the greenhouse once to lower the base numbers of pests and diseases and re-cultivate mother stems.

IV. Strengthen pest and disease control management

Under continuous high-temperature and drought weather, vegetable pests occur frequently. Physical and biological control measures such as insect-proof nets, insect-killing lamps, insect sex pheromones and colored boards, as well as high-efficiency and low-toxicity pesticides, should be vigorously promoted and applied to reduce the number of pesticide applications and the amount used, and attention should be paid to the pre-harvest interval to ensure the quality and safety of vegetables. Do a good job in disease and pest prevention and control for vegetable seedling raising, especially the control of viral diseases spread by pests. At the same time, pay attention to the safety of pesticide use, spraying when temperatures are low in the morning and evening to prevent plant phytotoxicity and heatstroke and pesticide poisoning among personnel. Since we are currently in a period of high typhoon frequency, all localities should also carry out targeted disaster reduction work such as typhoon and flood prevention.

V. Choose heat-tolerant and drought-tolerant varieties.

Choose fast-growing leafy vegetables and other vegetable varieties with relatively good heat resistance, such as fast cabbage, amaranth and water spinach. For fast cabbage, varieties such as “Zaoshu No. 5” and “Shuangnai” can be selected for sowing, and for heat-resistant green-stemmed bok choy, varieties such as “Japanese Heat-Resistant Green Vegetable King” and “Xiaguan” can be selected for sowing. Adopt “one film and two nets” covering. Use shade nets, insect-proof nets and greenhouse top film for rain-shelter covering to block strong light, lower high temperatures and prevent rainstorm impact.

VI. Shading and cooling.

In high-temperature weather, it is advocated to use protective cultivation measures such as covering the top of the greenhouse with shade nets to block strong light and lower high temperatures, so as to prevent high temperatures from scorching seedlings and reduce adverse effects. Where conditions permit, bases can cover insect-proof nets around the greenhouse to isolate pests.

Loosen the soil and remove weeds, and cover the bed surface. For open-field vegetables, keep the soil loose, reduce soil moisture evaporation, prevent weeds from competing for fertilizer and water, and promote plant growth. Combine bed surface covering with foliar fertilization, and spray phosphorus and potassium fertilizer to enhance the high-temperature resistance of vegetable plants.