What are the latest measures for frost protection of wheat in early spring?

Hoeing: When the soil is thawing and releasing moisture, hoeing the surface while it is still frozen can loosen the soil, preserve moisture, raise the temperature, and control weeds, enhancing the wheat seedlings' ability to withstand the cold. Regardless of whether the seedlings are weak, overly vigorous, or strong, hoeing should be done promptly during the green-up stage; for fields with a tendency toward excessive growth, deeper hoeing can be done as appropriate to suppress spring tillering. When hoeing, be careful to hoe shallowly and finely, and push apart clods as you go; if the soil is first pressed before hoeing, the soil will not be hollow, thus achieving the effect of loose on top and firm below, drawing up moisture and preserving it.

Pressing: Pressing the wheat field in early spring can crush clods, close cracks, bring wheat roots into close contact with the soil, and prevent cold air from intruding and harming the wheat seedlings. At the same time, pressing also has the effect of drawing up moisture, which can increase the water content of the soil surface layer and help buffer low-temperature cold damage.

Fertilizing: Fertilizing wheat in early spring can make up for the soil fertility consumed during winter, increase nutrient accumulation, promote the wheat seedlings' green-up growth, and resist or reduce early spring frost damage. This is especially important in years when winter temperatures are high, wheat seedlings continue to grow, and soil fertility is heavily consumed. Fertilizing wheat in early spring should seize the favorable opportunity when the soil has just thawed and is releasing moisture, and fertilizer should be applied deeply in furrows by taking advantage of the soil moisture; generally, watering should not be done, so as to avoid lowering the soil temperature and affecting the wheat seedlings' growth.

Spraying: From the green-up stage to the stem elongation stage of wheat, spraying 30-40 kg of 200 ppm paclobutrazol solution per mu can inhibit the wheat seedlings' growth and enhance their cold resistance.