Detailed Explanation of Key Cotton Planting and Management Techniques

Cotton is one of the most important crops in the world, with high yields and low production costs, which makes cotton products relatively inexpensive. Cotton fiber can be made into fabrics of many specifications, from light and transparent voile to thick canvas and thick velveteen, suitable for making all kinds of clothing, furnishing fabrics and industrial fabrics. Below is an introduction to cotton planting and management techniques.

I. Management during the sowing and emergence stage

Sowing is the foundation for achieving high-quality, high-efficiency cotton, and the main points to note are as follows:

1. Select excellent cotton varieties 

Focus on selecting early-maturing varieties. To ensure a full stand, a germination test must be done before sowing to determine the appropriate sowing rate. For machine sowing, the sowing rate is about 2 kg/mu; for manual dibbling, the sowing rate is about 1.5 kg/mu.

2. Adopt plastic film mulching technology

Plastic film has the effect of increasing temperature, preserving soil moisture and promoting early seedling growth. The suitable sowing period for film-mulched cotton is April 15-25; open-field cotton is generally sown after April 25 and finished around May 1.

3. Reasonable close planting

The principle to grasp is that plots with high water and fertility should be planted a little more sparsely, while dry and poor land should be planted a little more densely. For land of medium fertility, about 3500 plants per mu can be retained, and for dry and poor land, about 4000 plants. A wide-narrow row planting pattern should be adopted, with wide rows at 80 cm and narrow rows at 50 cm.

4. Apply sufficient base fertilizer and heavy flower and boll fertilizer

To achieve a seed cotton yield of 250-300 kg per mu, land of medium fertility should receive 10-20 kg of urea, 25 kg of diammonium phosphate and 10-20 kg of potassium sulfate per mu as base fertilizer; at the flower and boll stage, another 15 kg of urea should be topdressed. Insect-resistant cotton is relatively sensitive to organic fertilizer and potassium fertilizer, so organic fertilizer and potassium fertilizer should be increased. If potassium fertilizer is insufficient, cotton red leaf stem blight and late-stage premature senescence will occur, causing yield reduction.

II. Main management during the seedling stage

The period from emergence to squaring in cotton is called the seedling stage; for spring cotton it lasts about 45 days. For summer cotton it lasts about 35 days. The central task of field management in this period is: preserve a full stand, strive for early seedlings and promote early development.

1. Punch holes to release seedlings

In film-mulched cotton fields, when about 70% of cotton seedlings have emerged and the cotyledons are flat and the leaves have turned green, holes should be punched in time to release the seedlings. After releasing the seedlings, cover the film holes with soil to prevent moisture loss.

2. Check seedlings and fill gaps

After emergence, check row by row and fill gaps. In areas with missing seedlings, reseed or transplant in time; where few seedlings are missing, two plants can be retained on both sides.

3. Timely thinning and final singling of seedlings

For film-mulched cotton, thinning starts when seedlings are released and holes are covered; for open-field cotton, final singling is carried out when the seedlings grow 3 true leaves. Thin out the small and keep the large, remove the weak and keep the strong, forming a cotton field with uniform growth and reasonable density.

III. Management of cotton during the bud stage

The cotton bud stage is an important turning point in the entire growth process; managed well it is a treasure, managed poorly it is just grass. Therefore management must be strengthened.

1. Main objective

The main goal is to build a good plant framework on the basis of strong seedlings and early development at the seedling stage, and through management such as fertilizer and water, chemical regulation and pruning, and pest and disease control, to achieve increased budding and steady growth.

2. Management measures

First, watering should be done according to the land and the seedlings. Second, topdressing: combined with watering, about 8—10 kg of urea per mu can be topdressed at the full bud stage. Third, chemical regulation: for cotton fields with strong or vigorous seedlings, 1—1.5 g of mepiquat chloride per mu should be used, mixed with 5—20 kg of water and sprayed evenly to regulate vegetative and reproductive growth; especially before watering, chemical regulation must be carried out. Fourth, strengthen pest and disease control.

IV. Management of cotton during the boll stage

The period from flowering to boll maturity and boll opening in cotton is called the flower and boll stage. In general cotton fields this is from early July to early September; during the flower and boll stage, cotton growth still involves both vegetative growth and reproductive growth, but gradually shifts from the dominance of vegetative growth to mainly reproductive growth. The main direction in this period is to increase the setting of the three types of bolls. Its management techniques mainly include five aspects.

1. Apply heavy flower and boll fertilizer and supplement with topping fertilizer

The fertilization time is at the full flowering stage when 2 mature bolls have set on the lower part of the cotton plant; generally about 10-15 kg of standard nitrogen per mu is applied. If soil fertility is poor, cotton plant growth is weak and soil moisture is poor, the flower and boll fertilizer should be applied early, heavily and with water. Achieve “apply at flowering for use at boll stage.” To prevent premature senescence, strive to set autumn bolls and increase boll weight, for cotton fields showing a trend of fertilizer deficiency and premature senescence, from late July to early August, about 5 kg of standard nitrogen per mu should be applied. In the later stage of cotton, because root absorption capacity weakens, foliar spraying can be adopted, spraying 2-3 times with potassium dihydrogen phosphate or urea aqueous solution.

2. Timely drainage and irrigation

In this period, the Huaibei region is often in summer drought, so watering should be done in good time according to weather conditions, soil moisture and cotton plant growth. Our province has recently had continuous overcast and rainy weather, insufficient light, and some fields have standing water, so ditches should be cleared and water drained in time to reduce field humidity and lessen damage to cotton bolls.

3. Timely and careful pruning

Generally, fields are topped in late July to control apical dominance, avoid ineffective branches, concentrate nutrients for the needs of bud and boll growth, improve field ventilation and light penetration, reduce bud and boll shedding, increase boll weight and promote early maturity. When topping, 1 leaf and 1 growing tip should be removed. For cotton fields still growing vigorously later, when there are many late buds and ineffective flower buds on the upper fruiting branches, manual removal of the side growing tips can be used to remove late buds, and flower leaves should be removed in time, empty branches cut and superfluous buds wiped off.

4. Reasonably implement chemical regulation

At the flower and boll stage, spray 1-2 times with plant growth regulators such as mepiquat chloride to regulate the transport and distribution of nutrients in the cotton plant, enhance photosynthetic capacity, simplify later pruning and prevent excessive vegetative growth and late maturity.

5. Strengthen pest and disease control

The cotton flower and boll stage is the period when many pests and diseases such as summer aphids, cotton bollworm, cotton looper and red leaf stem blight occur and cause damage, so pest and disease forecasting should be strengthened and comprehensive measures taken for control to ensure a abundant cotton harvest.

V. Management of cotton during the boll-opening stage

The cotton boll-opening stage generally runs from late August to early November, lasting 70-80 days. The main objective of cultivation and management during the boll-opening stage is: promote early maturity of cotton, without premature senescence and without excessive vegetative growth. In order to strive for all cotton bolls to mature well, open smoothly, and mature early without premature senescence, first of all, work must be done well to protect roots and leaves; second, the environment should be improved to create favorable conditions for boll development and boll opening.

1. Spray foliar fertilizer in time

Generally, 1-2 sprays of foliar fertilizers such as urea, potassium dihydrogen phosphate or Tianda 2116 are applied before cotton harvest. This can improve the efficiency of leaf photosynthesis, promote cotton boll development, and play a role in increasing yield and improving fiber quality.

2. Resist drought and prevent waterlogging, adjust plant type

Although cotton does not need much water during the boll-opening stage, a moderate amount of water is still the guarantee for increasing yield and quality. Therefore, water when there is drought and drain when there is waterlogging. When watering, use small furrow irrigation and avoid flood irrigation; if waterlogging occurs, drain in time. For cotton fields with luxuriant branches and leaves, the lower old leaves can be cut off and rotten bolls removed. If the weather is rainy and humidity is high, the measure of merging ridges can be adopted, that is, while the soil is moist, pile two adjacent rows of cotton together in a “eight” shape. In this way, both sides of the two merged rows of cotton and the ground between the rows can receive sufficient sunlight, playing a role in ventilation, light penetration, warming and reducing humidity, so as to promote boll opening and reduce rotten bolls.

3. Chemical ripening and timely harvest

For cotton fields where the number of late autumn bolls is small in the later stage, normal boll development, maturity and boll opening cannot be completed, the proportion of pre-frost cotton is small, and autumn plowing and sowing of the next crop are affected, ethephon can be used for ripening. Choose clear weather 15-20 days before frost, use 40% ethephon mixed with 50-60 kg of water per mu of cotton field, and spray all cotton plants in the field, which can advance boll opening by 8-15 days; for normally opening cotton, harvesting is generally most suitable 5-7 days after the boll cracks, because harvesting too early will make the cotton poor in color and low in quality, and harvesting too late will reduce cotton fiber strength and shorten length.

Doing a good job in the management of each growth period of cotton is of great significance to realizing the yield and benefits of cotton planting. The above has introduced for everyone the key management techniques for each growth period of cotton, and I hope it can help everyone!