Rice and corn grain filling will be affected, southwestern China to see low temperatures and scant sunshine over the next ten days
Since late July, most of southwestern China has had many rainy days, with sunshine hours in Yunnan and Guizhou 30% to 80% below the same period in normal years; temperatures have been low, with Yunnan's average temperature at 21.1°C, the lowest since 1990. Single-season rice in southwestern China is at the critical stage of heading and flowering and grain filling, while summer corn is at the tasseling to grain-filling stage. Low temperatures, rain and scant sunshine will inhibit or delay rice flowering, causing poor pollination of rice ears and an increased rate of empty grains; at the same time, low temperatures and scant sunshine will also affect the grain-filling rate of rice and corn, leading to a decline in grain weight.
It is expected that over the next 10 days, western Yunnan, Sichuan and other places will still have relatively many rainy days, with cumulative rainfall generally 50 to 70 mm, among which parts of Yunnan, Guizhou and eastern Sichuan may reach 100 to 150 mm, with localized areas exceeding 200 mm.
In order to avoid or reduce the adverse effects of low temperatures, rain and scant sunshine on agricultural production, it is recommended that all localities pay attention to the late-stage management of autumn-harvest crops such as rice and corn, and adopt active and effective protective measures.
1. Keep a certain shallow water layer in rice fields, "shallow water promotes booting, moist conditions plump the grains," and adopt a method combining a shallow water layer, moist conditions and field drying in rice paddies to maintain the vigor of functional leaves and roots after heading, prevent premature aging, and increase grain weight.
2. Corn fields should receive a heavy application of ear fertilizer, and attention should also be paid to digging ditches for drainage to prevent lodging.
3. Monitoring and control of diseases and insect pests of autumn-harvest crops should be carried out well.