Key Field Management Techniques for Cotton During the Squaring Stage
Currently, cotton in Shache County is about to enter the squaring stage. All townships must attach great importance to field management of cotton fields during the bud and boll stage, and specifically provide technical guidance focused on fertilizer and water management, intertillage and weeding, and chemical regulation.
1. Prepare for the first watering
Conventional irrigated land should be intertilled, weeded, and have the film removed before the first watering, combined with furrow opening and topdressing, and ridges should be built before the first watering to make irrigation preparations.
2. Ensure irrigation quality
Good first watering is key. Adhere to the principle of not irrigating unless there is drought; the first watering should be late, generally at the beginning of flowering. Thin, water-deficient third-class cotton fields should be given the first watering earlier, while excessively vigorous cotton fields can be watered later, avoiding bud and boll shedding caused by drought stress from excessive water or too long an interval; 10-15 days after the first watering, apply the second watering. The second watering should be timely and thorough. For normal cotton fields, sandy soil can be watered somewhat earlier, while moisture-retentive soil should be watered somewhat later. Better to delay the first watering than to be late with the second.
3. Ensure scientific fertilization
From emergence to the squaring stage, cotton absorbs relatively few nutrients. According to growth conditions, in combination with spraying mepiquat chloride, use urea and monopotassium phosphate for foliar topdressing to supplement the nutrients needed for reproductive growth. For cotton fields with weak growth and slow growth after replanting due to disaster, apply 5 kg of urea per mu with irrigation to promote vegetative growth, and avoid burning seedlings by broadcasting urea. In addition, to prevent red leaf and stem blight, defoliation, and boll shedding caused by potassium deficiency in the later stage of cotton, foliar fertilizer should be sprayed together with insecticides in the early stage to supplement cotton's need for potassium and other rare trace elements.
4. Ensure rational chemical regulation
Advocate “less control and light control”, adhere to the principle of early, light, and frequent application, and according to growth and seedling conditions, use mepiquat chloride for timely chemical control to prevent excessive vegetative growth. For cotton fields with normal growth at the squaring stage, generally at 6-7 leaves and before the first watering, use 0.5-0.8 g of mepiquat chloride per mu for light regulation, to achieve stable and extended growth at the squaring stage; at the early flowering stage, excessive growth is likely, so three days before the second watering, spray 1.0-1.5 g diluted with water. For sensitive varieties such as Xinluzhong 26, use a lower dosage. When spraying mepiquat chloride, it can be mixed with 100 g of monopotassium phosphate and 50 g of urea for spray application, to promote young bud differentiation and a compact plant type.
5. Ensure integrated control
In response to the situation this year in which cotton aphids and cotton Fusarium wilt are occurring at a moderate-to-severe level in Shache County, all townships should strengthen forecasting and field monitoring, and achieve early investigation, early discovery, early reporting, early prevention, and early control. For cotton aphids, use methods such as dripping onto the growing point, stem smearing, removing infested plants, and washing with a urine mixture for spot and patch control, pay attention to protecting natural enemies, and avoid high-toxicity pesticides causing aphid resistance; for Fusarium wilt, field management can be strengthened to improve cotton plant disease resistance, and 30 g of 36% trichloroisocyanuric acid per mu or 20 g of fungicides such as Tefu Wither can be diluted with 35-40 kg of water and sprayed for control.