Pay attention to preventing dry hot wind in the late growth stage of wheat

Dry hot wind is a frequently occurring meteorological disaster in the late growth stage of wheat. After being damaged, wheat can generally lose 5%-10% of its yield, and in severe individual cases it can reach more than 20%. The harm of dry hot wind to wheat is mainly due to high temperature, drought, and strong wind, which cause large amounts of water in the air and soil to evaporate, and the water in the wheat plant is consumed very quickly, thereby destroying chlorophyll and other pigments, hindering photosynthesis, and causing the plant to quickly dry from the bottom upward. In early summer, which is exactly the wheat filling stage, if dry hot wind occurs, it is unfavorable for the wheat ears to fill, and they may wither and ripen prematurely, the grains become shriveled, and grain weight decreases, leading to severe wheat yield reduction.

Preventive measures: 1. Skillfully irrigate with wheat-yellowing water. About 10 days before wheat maturity, irrigate once with wheat-yellowing water, which can significantly improve the microclimate conditions in the field, reduce the harm of dry hot wind, and is also beneficial to interplanting in wheat fields and summer sowing. According to observations, after irrigating with wheat-yellowing water, the air temperature near the ground layer in the wheat field can drop by about 2°C, and the 1000-grain weight of wheat can increase by 0.8-1 gram.

2. Spray fertilizer on the leaves. From wheat flowering to the early filling stage, use 1%-2% urea solution, 0.2% potassium dihydrogen phosphate solution, 2%-4% superphosphate extract, or 15%-20% plant ash extract as foliar fertilizer, spraying 20-100 kg each time per mu, which can accelerate the growth and development of wheat in the late stage and prevent or reduce the harm of dry hot wind.

3. Spray vinegar on the leaves. During the early filling stage, spray 0.1% acetic acid or 1:800 vinegar solution on the leaves, which can reduce the opening angle of the stomata on the leaves, inhibit transpiration, and improve the plant's drought and heat resistance; at the same time, acetic acid (vinegar contains about 4.5% acetic acid) can neutralize the free ammonia produced by plant degradation under high temperature conditions, thereby eliminating the harm of ammonia to wheat.

4. Spray hormones on the leaves: ① From wheat flowering to the filling stage, spray 50 kg of 1000-fold petroleum growth promoter solution per mu, which can defend against dry hot wind, increase 1000-grain weight, and increase yield by an average of 7.8%. ② Before wheat filling, spray 50 kg of 40 mg/kg naphthalene acetic acid solution per mu, which can increase 1000-grain weight. ③ During the wheat filling stage, spray 25 kg of 60 mg phenoxyacetic acid solution per mu, which can also defend against dry hot wind and increase 1000-grain weight.