Prevention of 'Hot Dry Winds' in Huanghuaihai Wheat: Key Techniques

Currently, wheat in the Huanghuaihai region has fully entered the grain-filling stage, with more than 20 days left until widespread harvesting. This is a critical period for promoting grain filling and increasing kernel weight. This year, the winter wheat seedlings in the Huanghuaihai region have generally grown well, but by mid-May, the weather may be hot and dry, leading to rapid soil moisture loss. There is a high risk of “hot dry winds” in the northern part of Henan, southern Hebei, northwestern Shandong, and southern Shanxi. In addition, high temperatures and drought are favorable for the proliferation of wheat aphids, and in some areas, aphids on the ears are expanding rapidly. It is essential to focus on “one spray, three defenses” to prevent “hot dry winds.”

(1) One Spray, Three Defenses to Take Proactive Measures

“Hot dry winds” are a common meteorological disaster for wheat in the Huanghuaihai region during the later stages of growth. Once they occur, they can reduce photosynthesis in the leaves, accelerate leaf aging, and lower kernel weight and quality. Light “hot dry winds” can cause a decrease of 1-3 grams in the thousand-kernel weight, while severe “hot dry winds” can reduce the weight by 4-5 grams or more, leading to a decrease in both thousand-kernel weight and bulk density. In the early and mid stages of grain filling, spray a solution of monopotassium phosphate once to enhance the wheat’s ability to resist “hot dry winds.” In fields where aphids are more prevalent, applying “one spray, three defenses” can achieve integrated control of aphids, prevent diseases, combat “hot dry winds,” and prevent premature aging, which will help promote grain filling and dry matter transfer, stabilizing and improving the thousand-kernel weight.

(2) Scientific Irrigation for Early Prevention

For wheat fields with poor soil moisture, irrigate during the early stage of grain filling to meet the water requirements for wheat growth and to increase soil moisture. This will improve the microclimate of the field and prevent the damage caused by “hot dry winds.” Irrigation should be done on calm days to avoid excessive water that could cause lodging. Before the “hot dry winds” arrive, use sprinkler or micro-sprinkler irrigation systems to apply a moderate amount of water, increasing field humidity and lowering canopy temperature. This can help prevent or reduce the damage from “hot dry winds.”

(3) Timely Harvest to Ensure Safe Storage

The best time to harvest wheat is at the wax maturity stage. It is important to closely monitor weather changes and avoid continuous rainy spells to prevent ear sprouting and “wet wheat rain.” Early preparations should be made for harvesters, drying equipment, farm machinery oil, and storage facilities. Enhance training for mechanical harvesting to improve operational quality and minimize harvesting losses. If abnormal weather occurs, quickly initiate emergency response measures. Use information to guide the scheduling of machinery, and take measures such as coordinated efforts between cities and counties to mobilize harvesters, ensuring that machinery is ready before the fields.