Spring Management Techniques for Wheat

　　Wheat yield depends on three factors: the number of spikes per mu, the number of grains per spike, and the weight of 1,000 grains. The maximum product of these three factors represents the yield. Simply put, high yields come from having many spikes, large spikes, numerous grains per spike, and large grains themselves.

　　Tillering is the foundation for determining the number of effective spikes per unit area in wheat. Tillers that emerge before winter generally have a high likelihood of developing into spikes. Whether tillers that emerge in spring can effectively become spikes depends on the timing of their emergence: the earlier the tillering occurs, the greater the probability that these tillers will eventually develop into productive spikes. Therefore, spring management requires even more careful attention than pre-winter management.

　　Green-up Stage Management: Currently, winter wheat in China has already passed the green-up stage; here we’ll just briefly outline the key points. This past winter and spring, the winter wheat regions experienced relatively warm weather, resulting in larger wheat populations. Therefore, during this spring’s green-up stage, irrigation should be delayed and fertilizer applications reduced, in order to curb the tendency for excessive growth of the wheat population. In other words, the first irrigation of spring should be postponed until the tillering stage—before the wheat plants begin to elongate—and the fertilizer applied should be rich in nitrogen with some potassium, i.e., a high-nitrogen, medium-potassium, fast-release fertilizer. The choice of potassium-rich fertilizers is also motivated by the fact that increasing potassium nutrition can strengthen stem resilience and reduce the risk of lodging due to overly vigorous growth. The second aspect of green-up stage management is weed control, which involves two key technical points. First, for grassy weeds, if they were not controlled last autumn, they should be dealt with as early as possible this spring—specifically, before the wheat plants enter the tillering stage. For broadleaf weeds, select appropriate herbicides based on the dominant weed species; except for chlorflupyroxypyr, which can be applied after tillering, all other herbicides must be used before tillering. Second, regardless of the type of herbicide used, it’s crucial to apply the chemicals only when the weather is favorable—never spray during or immediately before a temperature drop, as this could easily lead to phytotoxicity. Additionally, herbicides should not be mixed with multiple insecticides, fungicides, or foliar fertilizers.

　　Management during the tillering stage: When wheat enters the tillering stage, the growth point at the top of the stem begins to differentiate into a developing ear—marking a shift from vegetative growth (focused on roots, stems, and leaves) to reproductive growth. This stage serves as a critical turning point between these two types of growth and is pivotal in determining the final plant height and the number of ears per acre. In other words, how tall this year’s wheat will ultimately grow and how many ears each acre will yield are essentially decided by the time of tillering. Therefore, if you continue to apply growth-regulating agents after tillering has begun, it’s like trying to light a lamp for a blind person—completely pointless. The wiser approach is to delay fertilizer and water application until the jointing stage, thereby minimizing nitrogen-induced increases in leaf area and appropriately supplementing potassium to enhance stem strength and resilience. Generally speaking, no further soil fertilization is needed after tillering has occurred.

　　After wheat enters the jointing stage, it becomes more sensitive to environmental conditions, and fluctuations in temperature can easily have a noticeable impact on the crop. However, April in the northern winter wheat region is often characterized by frequent cold fronts. During this period, it’s crucial to pay close attention to weather forecasts. As soon as a significant drop in temperature is predicted, it’s best to take preventive measures in advance—such as irrigating the fields or spraying amino acids or potassium dihydrogen phosphate—to mitigate the damage caused by the cold weather.