Four key aspects to focus on in late-stage cotton management

The main goal of late-stage cotton management is to promote cotton maturity, early boll opening, no premature senescence, and no excessive late-season green growth.

Do a good job of pruning

First, for cotton fields with lush foliage and heavy shading, remove the old leaves and empty branches on the lower part of the main stem. Second, promptly remove superfluous buds, adhering to the principle that superfluous buds should not exceed one cun. Third, tip the clusters, generally removing the cluster tips of the lower, middle, and upper fruiting branches in stages. Fourth, for cotton fields with particularly severe shading or during periods of abundant rain, carry out 2 to 3 rounds of pushing rows together to promote cotton boll maturity and reduce moldy cotton bolls.

Foliar fertilization to prevent premature senescence

Late-stage cotton management should focus on preventing premature senescence, and foliar fertilization should be used to meet the cotton's nutrient needs. For the first few foliar sprays, a multi-element fertilizer mixture composed of 1.2% urea, 0.3% potassium dihydrogen phosphate, 0.2% zinc sulfate, and 0.1% to 0.2% boric acid should be applied; for the later sprays, a 1% to 2% diammonium solution or 0.3% potassium dihydrogen phosphate solution should be applied, spraying 50 kg of fertilizer solution per mu each time, once every 7 to 10 days, to achieve the goals of preventing premature senescence and promoting early maturity.

Artificial chemical ripening

At the end of September and the beginning of October, choose a sunny day and spray 150 to 200 mL of 40% ethephon per mu mixed with 50 kg of water to promote early maturity. If continuous rainy weather occurs in the later period, pick the mature cotton bolls that have been in the boll stage for more than 40 days, soak them in a 0.5% to 1% ethephon solution, and then dry them in the sun (when the daily maximum temperature is below 20°C, plastic film can be used to cover them and raise the temperature, and after the pesticide effect has fully taken effect, dry them in the sun), which can yield cotton bolls that open normally. To ensure pesticide efficacy, the ethephon solution should be prepared and used immediately, and must not be mixed with alkaline pesticides for spraying.

Timely harvesting to ensure high yield

It is best to pick about 7 days after the cotton bolls crack and open, achieving "four clean, two not harvested." "Four clean" means the cotton bolls on the cotton plants are picked clean, the cotton segments inside the boll shells are removed clean, the cotton bolls on the ground are picked up clean, and the impurities in the cotton lint are removed clean. "Two not harvested" means cotton bolls that have not fully cracked and matured are not harvested, and cotton bolls with dew on the cotton lint are not harvested. In addition, strictly eliminate "three fibers" contamination; "three fibers" refers to chemical fiber, hair, and hemp fiber, etc.