How to Grow Cotton for High Yields? A Detailed Guide to Cultivation Techniques

I. Choosing Suitable Cotton Varieties

1. Liaomian No. 10

Plant height is about 70 cm, with dark green, broad leaves. It sets 8.43 bolls per plant; the bolls are round with a notched tip. Under open-field cultivation the growth period is 146 days, and under plastic mulching 137 days, making it suited to mulched cultivation, with a pre-frost boll rate of 83-90%. It has strong growth vigor, is easy to keep a full stand, does not senesce early, sets bolls well, and the bolls are uniform in size with concentrated boll opening. The average boll weight is 4.67 g, the lint percentage is 35.72%, and the fiber length is over 29 mm. It has strong stress resistance, with high resistance to Fusarium wilt, Verticillium wilt, seedling-stage diseases and boll rot. The plants are loose and vigorous, so planting density should not be too high: an average of 6,000-7,000 plants per mu, with 10-12 fruiting branches retained per plant.

2. Jinmian No. 3

An extremely early-maturing variety with a compact plant type, fruiting branches angled upward or cylindrical; plant height after topping is a strong 65 cm or so, the main stem is purplish red, and internode length is 5-6 cm. The leaves are relatively large, the leaves do not senesce, and the stem stays alive as bolls open. The bolls are ovoid, with a relatively thin shell that splits easily; boll opening is smooth and concentrated, with the burst period lasting 15-20 days. It sets 7.35 bolls per plant, with a boll weight of 5.89 g. The whole growth period is 135-140 days, and the pre-frost boll rate is over 85%. It is not resistant to Fusarium wilt or Verticillium wilt, and its resistance to seedling-stage diseases and boll rot, as well as its yield level, are slightly better than those of Liaomian No. 9. It can be planted somewhat more densely with more fruiting branches retained. Generally, on flat, fertile land keep 7,500-8,000 plants per mu with 8-10 nodes of fruiting branches; on sloping, thin land keep 9,000-10,000 plants per mu with 6-7 nodes of fruiting branches. In cold, rainy years retain somewhat fewer fruiting branches. It is suitable for planting in the cotton regions of northern and western Liaoning.

II. Open-Field Cotton Cultivation Techniques

1. Land Selection and Ridging

(1) Plot selection: Cotton is a warmth-loving and light-loving crop. Liaoning belongs to the extremely early-maturing cotton region and is the province at the highest latitude among the country's cotton regions; the cold, cool areas of the north are all unsuitable for cotton. Cotton has a well-developed root system, with roots reaching more than 2 m deep. Therefore, cotton fields should be chosen on flat land or sunny sloping land with deep soil layers and at least medium fertility. Heavy clay soil, shaded sites, and waterlogged, cold, slimy land are not suitable for cotton. As the farming saying goes: "Cotton seedlings are like fire; sandy loam is best."

(2) Ridging: Cotton seeds have strong soil-emergence ability, and they must push out two leaves as they emerge, so the resistance is great. Moreover, increased cotton yields in Liaoning depend mainly on the individual plant, so a certain density must be ensured, and keeping a full stand at sowing is the foundation of higher cotton yields. Therefore, cotton field preparation must be meticulous. Cotton seeds absorb water slowly when germinating; the seeds themselves are rich in fat and protein, their material conversion is slow, emergence takes a long time, and water absorption is large (equivalent to the seed weight), so the cotton field must maintain sufficient moisture. Cotton field preparation requires ridging as early as possible; autumn ridging is best, and spring ridging should also be completed before the end of March, at the latest no later than April 5 (before Qingming). Prepare the soil finely with no clods, loose on top and firm below, with soil moisture no lower than 18%. Fertilizer applied at ridging should be no less than 3,000 kg of farmyard manure.

2. Seed Treatment

(1) Fine soil selection of seeds: Cotton seeds must be carefully selected, removing shriveled seeds, large fuzzy seeds and bare seeds, so that the germination rate is no lower than 90%.

(2) Sunning seeds: The cotton seed coat is thick and poor at water permeability, so the seeds must be dried in the sun before sowing. Spread the cotton seeds out and sun them for 2-3 days on sunny days, turning them several times a day; it is best when the seeds rattle when shaken in the hand. When sunning seeds, be careful not to place the cotton seeds directly on cement or other surfaces that do not breathe well, to prevent dead seeds from the sunning. Sunning seeds not only improves the germination rate and enhances germination vigor, but also has sterilizing and insect-preventing effects, and should not be neglected.

(3) Delinting treatment: Delinting cotton seeds makes sowing easier (machine sowing absolutely requires delinting), and the removed lint can also be recovered as an industrial raw material -- cotton linters.

① Mechanical delinting. Cotton purchasing departments should give the cotton seeds one or two delinting passes, and where conditions permit, three passes. ② Sulfuric acid delinting. Sulfuric acid delinting is not only convenient for seed selection (through water selection, manual seed selection can be omitted), but can also remove insects and pathogens from the cotton seeds and facilitate seed coating. For delinting, add 500 mL of sulfuric acid at a temperature of 110-120 to every 10 kg of cotton seed lint, stirring while pouring, until the linters are completely dissolved, then wash with water and dry. ③ Chemical seed dressing to control diseases and insect pests: The currently promoted new cottonseed coating technology not only keeps a full stand, but also advances emergence by 2-3 days, reduces seedling-stage insect damage, and lowers costs. ④ Seed soaking and sprouting: Soak cotton seeds in 30-40°C water until the seed coat is thoroughly soaked and the cotton kernel swells in layers, then sow. When soaking seeds in warm water, turn them frequently to avoid heat accumulation burning the seeds; especially in cotton fields where seeds were destroyed by disaster and replanting is needed, to speed up soaking the water should be hot, and turning the cotton seeds is even more important. If the cotton kernel is found to have turned yellow, it means the seeds have been burned and can no longer be sown. In production practice, there is also the method of soaking seeds in 80-90°C water; this method can kill off poorly matured cotton seeds, but it must be noted that the seeds must be allowed to cool to about 20°C before stopping the turning. In arid areas, if sowing in water-filled holes, the seeds can be sprouted before sowing.