Low temperature and low light in southwest China will affect rice and maize grain filling in the next ten days.

Since late July, the number of overcast and rainy days in most parts of Southwest China is more, the sunshine hours in Yunnan and Guizhou are 30.8% less than that in the same period of normal year, and the temperature is relatively low, among which the average temperature in Yunnan is 21.1℃, which is the lowest since 1990. The first cropping rice in southwest China is in the critical stage of heading, flowering and filling, and the summer corn is in the stage from heading to filling. Low temperature and low rain will inhibit or delay the flowering of rice, poor pollination of rice ear and increase of empty shell rate; at the same time, low temperature and low light will also affect the grain filling rate of rice and maize, resulting in the decrease of grain weight.

It is estimated that in the next 10 days, there will still be a large number of rainfall days in western Yunnan and Sichuan, with accumulated rainfall of 50-70 mm, of which Yunnan, Guizhou and eastern Sichuan will reach 100-150 mm and more than 200 mm locally.

In order to avoid or reduce the adverse effects of low temperature and little rain on agricultural production, it is suggested that all localities should pay attention to the late management of autumn harvest crops such as rice and corn and take active and effective preventive measures.

The main results are as follows: 1. The paddy field should maintain a certain shallow water layer and "promote bud in shallow water and moist strong seeds". The combination of shallow water layer, wetting and drying should be adopted to maintain the vitality of functional leaves and roots after heading, prevent premature senescence and increase grain weight.

2. Ear fertilizer should be re-applied in corn field, and attention should be paid to ditch drainage and lodging prevention.

3. it is necessary to do a good job in the monitoring and control of diseases and insect pests of autumn harvest crops.