Cotton struggling to open its bolls? Reforming the planting method is key

In recent years, with the continuous deepening of the breeding of new cotton varieties and the improvement of sowing and seedling-raising methods, as well as the increase in the degree of agricultural mechanization, the planting method of cotton fields has become extremely important for high cotton yields.

In the era when conventional cotton varieties dominated, cotton sowing was mostly direct seeding, cotton planting density was relatively high, cotton row spacing was relatively small, and cotton fertilization was mostly broadcast application. After hybrid cotton was promoted and applied on a large scale, because the individual development of hybrid cotton is larger, cotton field density was continuously reduced, cotton row spacing was expanded, and cotton fertilization was mostly changed from broadcast application to band application or hole application. When agricultural machinery gradually entered cotton fields, cotton row spacing was further expanded, and cotton fertilization accordingly changed from shallow ditch and shallow application to deep ditch and deep application. It can be seen that fertilization methods also evolved continuously along with the reform of planting methods.

When we conducted large-scale multi-point surveys of cotton production conditions, we often encountered cases of contradiction between cotton fertilization and cotton planting methods in the field. Some farmers applied excessive nitrogen fertilizer, and some farmers applied too large a single dose of fertilizer, often causing excessive vegetative growth or rampant growth of cotton, resulting in premature closure of the rows, severe shading in the cotton field, and thus a large number of cotton buds and bolls shedding, or after boll setting, because the cotton row spacing was relatively narrow, ventilation and light transmission conditions deteriorated, cotton boll maturity time was delayed, and boll opening was poor. Farmers often attributed the cause to seed problems, argued with cotton seed supply departments, and demanded compensation. However, the same cotton variety showed increased yield and a bumper harvest in cotton fields with reasonable planting methods. The reason was that these farmers achieved scientific formula fertilization for cotton, the cotton row spacing was relatively large, and the cotton field environment and growth performance were characterized by "closed at the bottom but not closed at the top, a gap in the middle, sunlight can shine in, air can circulate, small leaves and large cotton bolls, stable plants that do not surge upward." The ecological environment for the cotton itself to survive was good; therefore, there were many bolls set, smooth boll opening, and relatively harmonious development of individuals and the population. Good varieties matched with good methods can fully show the advantage of increased yield.

In cotton areas with a relatively large hybrid cotton area, continuously reforming the planting method is one of the effective ways to create reasonable living space for cotton and explore high cotton yields. The advantages of reforming the planting method are: first, it facilitates machinery entering the field for cultivation, which is beneficial for deep intertillage, deep application of base fertilizer, and high ridge earthing up; second, it facilitates topdressing, pest and disease control, pruning and branch removal, and other field management; third, it facilitates drainage and drought resistance, enhancing disaster resistance; fourth, the cotton spatial distance is relatively large, light is sufficient, air circulates, photosynthetic efficiency is high, and nutrients are produced quickly; fifth, it can fully display the characteristics and traits of hybrid cotton; sixth, bolls set quickly, the boll-setting rate is high, the shedding rate is low, and there are few rotten bolls, thus enabling high quality and high yield.

At present, the hybrid cotton planting area is relatively large. In terms of planting method, narrow rows should be changed to wide rows, and the planting method of wide rows and dense plants should be advocated. In places with relatively high fertility levels, the bed width should preferably be 2-2.4 m (including ditches), with two rows of cotton planted, row spacing 1-1.2 m, plant spacing 0.45-0.5 m, and a density of about 1,300 plants per mu. In places with medium fertility, the three-equal-row method can also be used, but the row spacing must not be less than 1 m. With the above planting methods, under relatively high management levels, the number of bolls set per cotton plant is generally about 45, the number of bolls set per mu is 55,000-65,000, and an average of about 600 jin of seed cotton per mu can be expected to be achieved. Right now, autumn sowing production is imminent. In cotton areas with relatively large hybrid cotton planting in various places, the experience and lessons regarding cotton planting methods should be summarized in a timely manner, and next year's planting methods can be adjusted accordingly. This can also be continued during the relatively leisure winter season.