Opinions on the management of high-temperature field defense in the early growth stage of early rice in South China

At present, the early rice in the south has entered the stage of heading and flowering and filling. According to the National Meteorological Administration, on June 19, Jiangnan and South China will have a wide range of high temperature and hot weather. The maximum daily temperature will be 35-39 °C, and the local area will reach 40-41 °C. The high temperature weather may last for more than 10 days. . Continued high temperature is not conducive to early rice pollination and grouting, affecting the seed setting rate and 1000-grain weight. In response to the current early rice growth and meteorological conditions, the Ministry of Agriculture's Rice Experts Steering Group and the National Agricultural Technology Extension Service Center discussed technical guidance for strengthening post-field management, avoiding and mitigating high temperature and heat damage.

(1) Adjusting water with water to strengthen water management. During the period of heading and flowering, there is a high temperature weather above 35 °C. It is necessary to inject deep water in time to keep the water layer 4-5 cm in the field, effectively reducing the temperature of the ear layer. Where conditions permit, the method of daily irrigation can be adopted to adjust the group. Microclimate, increase the seed setting rate. During the filling and filling period, it is necessary to keep the dry and wet in the field, mainly wet, improve the soil oxygen supply capacity, maintain the root activity of the plant, and achieve the purpose of root protection. In the later stage, avoid water prematurely, prevent premature aging and high temperature ripening. .

(2) Topdressing outside the roots to improve the ability to resist stress. After no flowering in the morning or lowering the temperature at 4 pm, foliar application of 3% superphosphate solution or 0.2% potassium dihydrogen phosphate solution enhances the resistance of rice plants to high temperature, prevents premature aging, and effectively reduces high temperature heat. Harm, increase the seed setting rate and 1000-grain weight.

(3) Pursue grain fertilizer and promote recovery. After the high temperature, for the lighter field, strengthen the field water and fertilizer management, promote grain filling, increase grain weight, and reduce losses; Apply 1-2 kg of urea to the acre or apply foliar fertilizer to enhance the photosynthetic capacity of the later leaves and promote grain filling and fruiting.

(4) Strengthen monitoring and improve pest control. High temperature and high humidity conditions are likely to cause aggravation of pests and diseases. All localities should continue to monitor and monitor pests and diseases, strengthen the prevention and control of pests and diseases that focus on rice “two-shift” pests, rice blast, and sheath blight, and vigorously promote professional rule. Improve the control effect, reduce the amount of pesticides, effectively reduce the loss of pests and diseases, and ensure the stable production and yield of early rice.

(5) Harvesting at the right time to prevent “cutting green”. Early rice harvest early or late, affecting yield and quality. During the harvest of southern early rice, it is likely to suffer from continuous high temperature and heavy rain, and it is prone to spike germination, resulting in reduced yield and quality. All localities should make good preparations for materials and technology in advance, timely harvest and harvest, and vigorously promote the mechanization of straw smashing devices to improve harvesting efficiency. Generally, it is harvested about 25 days after the heading, when the whole ear loses green, and when the hull is 90% yellow, it is prevented from appearing. Advocate concentrated drying, avoid mold, and make the particles return to the warehouse.