Cotton is fastidious because of seedling fertilization at flowering and boll stage.

In June, there was frequent plum rain after cotton budding in Hubei cotton area. coupled with the differences in field management, the cotton growth progress was inconsistent. The cotton with earlier development has produced 1 or 2 peaches per plant, while the cotton with late development has just budded, and the difference in development progress is 20 to 30 days. Therefore, different measures should be taken in cotton fertilization management.

According to the cotton seedling situation investigated in the field, half of the 26 mu cotton leaves of Wang Hua, No. 5 Squadron of Diaodong Farm in Hanchuan City showed obvious lack of potash fertilizer, so it was suggested that he should apply potash fertilizer immediately. Xiao Qihua's 40 mu cotton of 8 groups in Sujiapu Village, Taodian Township, Huangzhou District has generally flowered and grown steadily. He originally planned to apply ammonium bicarbonate and phosphate fertilizer, but we suggested that he should apply high content compound fertilizer and potash fertilizer. Nearly 20 mu of cotton fields owned by Zhang Xiangbing in Qunfeng Village, Zuru Town, Caidian District, are generally short of potassium, nitrogen and boron. We ask him to apply nitrogen, potassium fertilizer and boron fertilizer quickly and deeply.

The flowering and boll stage is the key period for cotton to gradually change from vegetative growth to reproductive growth, and it is also the peak boll setting period for cotton. According to the growth law of cotton for many years, the peach period of cotton is from late July to early August. This period is the golden period of cotton boll setting, and it is also the period when cotton needs the most fertilizer, but specific to different cotton fields, it must vary from seedling to seedling.

For cotton in the peak flowering period, because vegetative growth is still in parallel with reproductive growth, partial application of nitrogen fertilizer will lead to cotton vigorous growth and crazy growth, which will not only aggravate the shedding of buds and bolls, but also cause premature senescence. Due to the excessive shade in the cotton field, high humidity, lack of ventilation and light, the lower cotton peach is very easy to mildew and rot, resulting in a reduction in cotton production. Therefore, part of cotton entering the flowering stage should mainly apply compound fertilizer, with a high content of compound fertilizer 15-20 kg per mu, or a small amount of urea, combined with phosphorus and potassium fertilizer, especially for farmers who select insect-resistant cotton varieties, they should apply more potash fertilizer, not less than 15 kg per mu of potash fertilizer, intensive application of potash fertilizer at flowering stage, and cultivation of soil.

Peach fertilizer should be applied to boll-bearing cotton, and peach fertilizer should be applied twice in areas where hybrid insect-resistant cotton is planted. When there are 2-3 adult peaches per plant, about 15 kg of urea should be applied per mu. When there are about 10 mature peaches per plant, about 15 kg of urea should be applied again. When there are more cotton peaches, there is no need to worry about the excessive growth of urea, because after cotton setting peaches, the direction of nutrient transport has shifted from branches and leaves to cotton bolls, and the timely supply of sufficient nutrients can not only increase boll weight and seed index weight, but also improve quality. However, the application period of peach fertilizer can not be too late, too late application will only lead to greedy green late ripening.