How to manage cotton during the dog days? Please check this guidance

According to the citywide "7 15" survey summary, this year our city's cotton growth progress is fast and the cotton is growing well. This is shown by: fast growth progress, uneven growth, and a large area of cotton entering the dog days with bolls. The citywide average cotton plant height is 88.38 cm, an increase of 2.01 cm over last year; the total number of fruiting nodes is 49.80, an increase of 7.77 over last year; the number of abscised squares and bolls is 4.39, a decrease of 0.15 over last year; the abscission rate is 8.8%, a decrease of 1.99 percentage points over last year. The area entering the dog days with bolls accounts for 100% of the cotton field area, achieving full entry into the dog days with bolls.

While the cotton production situation is very good, the following problems still exist: First, management in some cotton fields is lagging. About 20% of cotton fields citywide still have not been ridged and earthed up around the plants. The area where flower and boll fertilizer has been applied is not large, and compared with this year's cotton seedling growth progress, it is clearly lagging. Second, pest and disease occurrence is relatively serious. According to surveys, the third generation of cotton bollworm is occurring at a moderate to severe level, and red spider mite damage is rampant. Fusarium wilt, cotton aphid, and plant bugs have also occurred to a certain extent. Third, some cotton fields show a trend of premature senescence.

Based on the current characteristics of the cotton seedling situation, the following management measures should be effectively carried out at present:

1. Apply boll fertilizer heavily and strictly prevent premature senescence. Flower and boll fertilizer is the "third solid meal" for cotton and is related to the level of cotton yield, so all localities should apply it early, universally, and heavily. First, apply early: begin application when the average per plant has 0.5-1 large boll, and finish applying before July 25; second, apply universally: persist in applying to every field; third, apply heavily: apply 15-20 kg of urea per mu, plus 10 kg of potassium fertilizer; use spot application or furrow application for deep placement to improve fertilizer efficiency. Before August 10, apply a topdressing fertilizer universally as appropriate according to the seedlings, with 8-10 kg of urea per mu.

2. Seize the timing and prevent pests and diseases well. During the flower and boll stage there are many pests, in large numbers, causing severe damage. The main pests include cotton bollworm, pink bollworm, red spider mite, aphid, plant bug, and others. All localities should strengthen forecasting, carefully organize control campaigns. Focus on controlling the third and fourth generations of cotton bollworm, while also controlling pink bollworm. Spot-treat red spider mite and aphid. At the same time, combine pruning, topping, and removal of superfluous buds with picking off eggs and catching insects.

3. Top early and rationalize chemical regulation. This year cotton growth is earlier, with many fruiting branches, so topping can be done appropriately earlier. From late July to early August, top the cotton seedlings when they have 20-22 layers of fruiting branches. Combined with topping, prune and remove leaves in stages, thoroughly remove side shoots, remove superfluous buds, concentrate nutrients to push large bolls, and improve ventilation and light penetration to reduce rotten bolls. For first- and second-class cotton fields, spray 3-3.5 g of mepiquat chloride per mu mixed with 45 kg of water to control excessive growth and promote steady growth; for third-class cotton fields with poor growth, combine foliar fertilizer spraying with the application of plant growth promoters such as "802" to promote rapid frame formation. Five to seven days after topping, use 4-5 g of mepiquat chloride per mu mixed with 45 kg of water for chemical shaping.

4. Harvest intercropped and relay-cropped crops promptly, and clear stubble and rows in time. All localities should seize the time and promptly harvest watermelons, melons, and soybeans intercropped in cotton fields. Achieve rapid harvesting and rapid row clearing.

5. Fight drought and drain waterlogging to ensure a bumper harvest. Summer and autumn drought can easily lead to massive abscission of squares and bolls and premature senescence of cotton plants. Drought resistance criteria: no rain for 7-10 consecutive days; field water-holding capacity below 60%; the top 3-4 true leaves of the cotton plant wilt at noon and appear dark green, and cannot recover by 3-4 p.m. Drought resistance methods: furrow irrigation with a small stream in the morning and evening and carrying water for irrigation, and after irrigation promptly cultivate and loosen the soil to preserve moisture. If heavy rain occurs, promptly clear ditches and drain waterlogging to ensure normal growth of the cotton plants.