cold spring is a common natural disaster in the management of winter wheat in spring. It has occurred frequently in recent years, which has seriously affected the high and stable yield of wheat. Therefore, scientific prevention and response to cold spring are of vital importance to wheat production.
After entering March, due to the rapid rise in temperature, the daily average temperature has reached or exceeded 10℃. At this time, winter wheat is in the stage of getting up and jointing, which is a critical period for wheat growth. Once the cold wave arrives, the temperature suddenly drops suddenly, and the low temperature reaches about 0°C, which is extremely prone to frost hazards. In the lighter case, the wheat leaves become white and dry, and the initial stage is like boiling water. In the worst case, the young wheat ears are frozen, and the ears or deformed ears cannot be drawn in the later growth period. The production loss is serious.
Preventive measures for wheat”spring cold”
Classification management:Combine the characteristics of seedling conditions and weather changes to classify and guide wheat fields, strengthen field management, and improve the cold resistance of plants.
1. For the flourishing wheat fields, we should focus on”control”, and take measures such as suppression, deep hoeing, and spraying plant growth regulators to prevent wheat from overgrowing. Fast growth and development, avoid premature jointing of wheat, improve cold resistance, and at the same time improve wheat lodging resistance.
2. For the prosperous long wheat field in spring, the first fertilizer can be postponed to the late stage of getting up or before and after jointing.
3. For the general wheat field, it is necessary to”promote the combination of control”, suppress first, then shallow tillage, in order to achieve the effect of increasing temperature and maintaining moisture. Appropriate amount of topdressing and watering during the rising period can promote the growth of tillers and strive for more ears.
4. For weak seedlings and fields, we should focus on”promoting”. Try to plan the hoe as early as possible, increase the ground temperature, increase the tiller roots, and pay attention to the shallow hoe. Avoid injury to the roots. After turning green, it is necessary to apply quick-acting nitrogen fertilizer in combination with moisture content. As long as the moisture content of weak seedling fields is acceptable, watering in early spring should be avoided to avoid lowering the ground temperature. Topdressing and watering are usually carried out in the late stage of returning to youth or the early stage of getting up.
Watering before freezing:Watering before freezing is one of the most effective measures to prevent cold from falling spring. Before the arrival of a strong spring cold, wheat fields that are at risk of freezing damage must be watered in time to adjust the microclimate near the ground layer, which can significantly reduce freezing damage.
Increasing the application of organic fertilizer:During the jointing stage of wheat rise, add some organic fertilizers, phosphate fertilizers, and potassium fertilizers to promote root development, inhibit the growth of the above-ground part of wheat seedlings, and strengthen Cold resistance.
Spraying regulators:Before the arrival of cold spring, foliar sprays of nutritional regulators can improve plant immunity and the ability to fight various disasters and reduce harm.
Remedial measures after the wheat”falling spring cold” disaster
Fertilization and watering:Wheat is a crop with tillering characteristics. Wheat fields that suffer from early spring freezing will not freeze all the tillers to death, and there are small tiller buds. The long components till into ears. As long as management is strengthened, a good harvest can still be obtained. The wheat affected by early spring freezing damage should be immediately applied with available nitrogen fertilizer and watering. The synergistic effect of nitrogen and water will promote early tillering of wheat, small tillers catch up with large tillers, increase the rate of tillering ears, and increase the number of ears per mu, thereby reducing the loss of freezing damage. . Generally, topdressing urea is about 10 kg per mu.
Cultivation to protect moisture:increase the ground temperature, increase the number of tillers, and get a good harvest.
Spraying foliar fertilizer:After the wheat is frozen, spray the leaf surface with nutrition regulator or multi-resistance-increasing agent in time, which has obvious effect on the recovery of wheat growth. The promotion effect is manifested by the rapid growth of medium and small tillers and the rapid emergence of latent buds.
Do a good job of pest control:Frozen wheat fields are more vulnerable to pests and diseases, and should be controlled in time. To prevent wheat sharp blight, powdery mildew and rust, triadimefon, tebuconazole, etc. can be sprayed. Aphids can be controlled by spraying imidacloprid, acetamiprid, etc.
After entering spring, the management measures for winter wheat mainly to prevent and control diseases and insect pests should be kept up in time. Especially after the early spring cold occurs, we must pay close attention to this work so that the winter wheat plants in the wheat fields that have been damaged by the early spring cold can quickly resume growth after getting sufficient nutrients. Even if there is no downturn in spring, we must strengthen the management of wheat fields in spring, so that winter wheat plants can form strong seedlings as early as possible in spring, and lay the foundation for the healthy growth of wheat in the middle and late stages.