According to the forecast of the Central Meteorological Observatory, in the near future, parts of North my country, Northwest China, Southwest China, Central China and East China will experience periodic high temperature or continuous high temperature weather, and meteorological drought may develop in some areas. In order to reduce the adverse effects of disastrous weather on horticultural crop production, the Crop Management Department of the Ministry of Agriculture and Rural Affairs organized the National Agricultural Technology Extension Service Center, the Vegetable, Fruit Tree and Tea Expert Guidance Group of the Ministry of Agriculture and Rural Affairs and related industrial technology systems to study and propose technical guidance opinions on fruit, vegetable and tea production in response to high temperature and drought.

I. Vegetables

(I) Strengthening the management of high temperature and drought resistance

1. Strengthening sunshade and moisture conservation. Facility vegetables are covered with sunshade nets, cooled by wet curtains, cooled by spraying, and covered with grass on the ground. Focus on strengthening sun protection and moisture conservation measures for fruits and vegetables, reduce direct sunlight, and reduce the temperature of the vegetable root zone; at the same time, remove aging and yellow leaves, weaken the transpiration of plants, reduce water evaporation, and promote vegetable growth.

2. Actively divert water for irrigation. Use drip irrigation or small ditch infiltration irrigation to carry out emergency irrigation for drought-prone fields; fruits and vegetables in the harvest period should be appropriately topdressed with water. Irrigation should be carried out in the morning and evening when the weather is cool, and avoid flooding during the high temperature at noon. If conditions permit, artificial rainfall can be used to alleviate drought.

3. Do a good job in pest control. During the high temperature and drought period, airborne diseases such as powdery mildew and rust and insect pests such as whiteflies and cutworms are prone to increase. High-efficiency, low-toxicity, and low-residue pesticides should be selected for timely prevention and control. In hot weather, pesticides should be applied before 8 am or after 5 pm to avoid pesticide evaporation due to high temperature or plant burns caused by the liquid.

4. Harvest and market in time. Harvest vegetables that meet the harvesting standards in time; harvest vegetables that still have commercial value in the affected vegetable fields as soon as possible to minimize economic losses.

(II) Actively promote autumn sowing production

1. Prepare a kang for the shed. After clearing the field stumps, the vegetable facilities can be sprayed with water, sealed with film, and high-temperature humidified; open-field vegetables should be deep-turned in time, and the soil should be heated to kill pests and pathogens in the soil to create favorable environmental conditions for autumn vegetable production.

2. Popularize water-fertilizer integration. Large-scale vegetable production bases should build water-fertilizer integration facilities, popularize and apply precision irrigation and fertilization technology, and achieve water-saving, high-yield and high-efficiency production as much as possible.

3. Sow leafy vegetables as soon as possible. Seize the favorable opportunity of high prices during the "autumn off-season" of vegetables, speed up land preparation and sow a batch of fast-growing leafy vegetables. Vegetable varieties with strong drought resistance and good heat resistance can be selected, such as dwarf resistant green cabbage, amaranth, leaf potato tips, early celery, lettuce and other fast-growing leafy vegetables.

4. Actively cultivate strong seedlings. All localities should actively organize intensive nursery farms to cultivate strong vegetable seedlings. Seedling facilities should pay attention to shading and cooling, and use 30-50% shading nets to avoid high temperature burning of seedlings and weak light growth.

5. Provide shade and sun protection. All localities should actively transport and prepare autumn vegetable seeds, organize the sowing of autumn vegetables, and transplant fruit and vegetable seedlings in time. After seedlings and transplanting, shade nets should be used to cover in high temperature weather. Light-loving vegetables should choose silver-gray shade nets with low shading rate, and shade-tolerant vegetables that like weak light should choose black shade nets with high shading rate.

2. Fruit trees

(I) Strengthen irrigation and cooling and sun protection

High temperature heat damage generally occurs at the same time as drought. Reasonable irrigation should be used to increase soil moisture, reduce soil temperature in orchards, and alleviate the harm of high temperature and drought. In the early morning or evening, use sprinkler irrigation, micro-sprinkler irrigation or drip irrigation to irrigate in small amounts and multiple times to avoid flooding. When using hole irrigation and furrow irrigation, dig 2-4 loose soil pits around the drip line of the crown, with a width and depth of about 30cm. Water the loose soil pits each time to improve the irrigation effect. Try to avoid high temperature periods during irrigation time to avoid cold water irrigation that aggravates the physiological wilting of trees. According to the temperature conditions, the crown can be sprayed with water to cool down and increase humidity, improve the microclimate of the orchard, and alleviate the damage of high temperature and direct sunlight to the tree and fruit. Young orchards, fruit trees cultivated in facilities, or orchards with high economic benefits can be covered with shade nets to reduce direct sunlight. When covering, be careful that the covering material does not directly contact the plants.

(II) Strengthen the management of soil and trees

Loosening the soil, growing grass, and covering the surface can significantly reduce the surface temperature and delay water evaporation. The orchard should retain shallow-rooted short-stem grass outside the tree tray. On the basis of irrigation, orchards with conditions can loosen the topsoil or cover the tree tray with straw, husks, weeds, and degradable weed-proof cloth to increase moisture retention and heat insulation, and enhance the cooling and drought resistance of fruit trees. Prune branches and leaves appropriately to cultivate reasonable trees. High temperature and low humidity environments are prone to outbreaks of pests such as red spiders and yellow spiders. Pay attention to pest monitoring and timely prevention and control. Harvest mature fruits in time to reduce yield losses and tree water and nutrient consumption. At the same time, we should prepare for the sudden change of high temperature drought and rainstorm and flood. For orchards prone to waterlogging, we should clear and dredge the drainage ditch in advance, and ensure that the depth of the main drainage ditch reaches more than 60cm.

(III) Do a good job of post-damage recovery management

After the high temperature and heat damage occurs, we must first ensure the stability of field water holding capacity. After the heat damage and drought, the tree body is weak and the root system is damaged, and the root system's nutrient absorption capacity decreases. We can increase the quality of fruit tree leaves, photosynthesis rate and transpiration rate by spraying potassium dihydrogen phosphate on the leaves. If it rains after continuous high temperature and drought, fruit cracking is likely to occur. It is not advisable to apply a large amount of fertilizer to the roots immediately. We can spray 0.2%-0.4% potassium dihydrogen phosphate, 0.5% potassium nitrate and other foliar fertilizers in time to promote tree recovery and prevent secondary losses after rain. After the high temperature and drought are relieved, the dead branches should be pruned in time. For fruit trees with a large number of dead branches, the incisions should be treated with preservatives in time. Clean up plants that are not worth saving in time, and replant seedlings in time when the weather is suitable.

3. Tea Garden

(I) Strengthen the management of high temperature and drought resistance

1. Cover and shade. Use trellises and other methods to cover the tea tent with shade nets to reduce the intensity of direct light. The shade net should be more than 50cm higher than the tea tree to avoid being too close to the tea tree and causing burns.

2. Cover with grass. Cover the rows of tea gardens with grass. Use about 1 ton of hay per mu, with a thickness of 5-10 cm. You can cut mountain grass and weeds, or use rice straw, wheat straw, bean straw, bagasse, wood chips and tea garden pruning branches and leaves as forage sources.

3. Timely irrigation. Before the high temperature and drought come, build reservoirs, ditches, channels, etc. in advance, and install plastic rainwater collection pits, sprinkler irrigation and other water-saving irrigation facilities. When the relative moisture content of the tillage layer of the tea garden drops to about 70%, or the average daily temperature reaches above 28℃ and there is no rain for 7-10 days, irrigate and replenish water every morning and evening.

(II) Do a good job in post-disaster recovery management

1. Tree management. After the high temperature is basically relieved and the soil in the tea garden is moist, the affected tea garden should be handled in time.