Cotton Growing: Proper Conditions And Smart Cultivation

Where And When Is Cotton Grown?

Cotton thrives in warm regions, and the United States, Uzbekistan, India, and China are the major cotton growing countries, producing most of the world’s supply. Turkey, Brazil, and Pakistan also rank among the world’s top crop producers. However, the prevalence of intensive agriculture steadily reduces the productivity of cotton growing fields in these countries.

The warmer months are ideal for growing cotton. Planting normally occurs between April and June, and harvesting occurs between August and September, depending on the local climate.

Optimal Conditions To Grow Cotton

The success of the crop largely depends on the weather and the quality of the soil. Let’s dig deeper into the crucial growing conditions that matter most for cotton crop productivity.

Climate Requirements: Temperature And Precipitation

The climate for growing cotton should be warm and humid. The crop grows well in areas with lengthy frost-free periods as well as lots of heat and sunlight.

Throughout the active growth period, the ideal temperature for growing cotton is between 70 and 100°F (21 and 37°C). Although temperatures exceeding 100°F (37°C) are dangerous for growing plants, short exposure to temperatures up to 110°F (43°C) typically doesn’t cause serious harm, provided the air is humid. The crop is most economical to grow in areas that receive between 33 and 43 inches (850 and 1100 mm) of rain per year. High yields necessitate at least 20 inches (500 mm) of evenly distributed rain.

Soil Requirements: Type And pH

Cotton may grow practically anywhere, as long as the soil drains well (which it usually does on mild slopes). Yet, it is generally assumed that sandy loam rich in clay and organic matter and containing normal amounts of nitrogen (N) and phosphorus (P) is the ideal cotton growing soil. Loamy soils high in calcium carbonate typically produce maximum yields.

The optimal pH range for growing the crop is between slightly acidic and slightly alkaline (5.8 and 8.0). Decreases in yield tend to be insignificant until the pH falls below 5.5 on sandy loams and 5.2 on silt loams.

Preparing The Soil For Growing Cotton

Before starting the cotton planting season, you have to prepare the soil. First, remove any debris and growing weeds. Next, the soil should be plowed or tilled deeply to break up any clumps and promote better air circulation. Ensure that the soil temperature 6 inches (15 cm) underground reaches at least 60°F (15°C) and keep checking for the next three mornings. Once the temperature has stabilized at this level, the soil is ready for cotton planting and growing.

Add some compost or aged manure to the soil to improve its structure, health, and fertility. Also, conduct soil testing to determine the optimal amounts of macro- (nitrogen, phosphorus, and potassium) and micronutrients (calcium, magnesium, iron, zinc, etc.) for cotton growth and development.

While collecting soil samples might be costly, productivity maps in EOSDA Crop Monitoring can help you cut down on the amount of samples you need to take. Years’ worth of field vegetation data are used to create productivity maps, which reveal low-productivity areas. This means that soil can be sampled only in the less productive areas that require it the most. By collecting samples in specified areas, farmers can find out the causes of low yields there, such as a macronutrient deficiency or excess, and eliminate the guesswork from their amendment and fertilizer applications.

Practices Of Cotton Sowing

When choosing dates to plant cotton, consider growing conditions rather than the calendar. A minimum soil temperature for planting cotton 60°F (15°C) will ensure optimal germination. Lower yields can be expected from crops sown in cooler soils due to higher rates of stand loss and possibly weaker survivors.

Due to machinery limitations, traditional cotton plant spacing was 36–40 inches (91–102 cm). Some farmers are increasing the density of their crop population by switching to narrow-row growing, which involves sowing the seeds 15 inches (38 cm) apart.

A young plant is weak early in the growing season. When deciding on cotton planting depth, keep in mind that if you plant too deeply, the emerging seedling might grow weaker, less likely to form a robust stand, and more vulnerable to damage ^{Collins, G., Edmisten, K. (2017, April 13). Tips for Successful Cotton Planting. North Carolina (NC) State University Extension.}. Sow seeds into damp soil at a depth of no less than 0.5 foot (13 cm), ensuring optimum seed-to-soil contact, and no more than 1.5 feet (38 cm), allowing them to grow as easily as possible.

How To Take Care Of Cotton Plants Sustainably

To optimize yields and ensure the fiber’s quality, it’s vital to give growing plants thorough care. At the same time, sustainable crop maintenance must strike a balance between crop needs, resource efficiency, and environmental conservation.

Efficient Watering

Plants need more water in hotter and drier growing conditions. Cotton plant water requirements in a desert climate might be as much as 40 to 50 inches (1000 to 1500 mm) annually. Reduced water needs of 20–30 inches (500–760 mm) are typical in a more moist and temperate climate.

Plant water consumption grows steadily from the early stages, when moisture is lost mostly through evaporation, to the later stages, when active plant transpiration occurs. The plant uses the most water in the middle of the growing season, when its canopy is fully expanded and a boll load reaches its peak.

The amount of water required to grow cotton at different stages may be determined using daily temperature readings and estimated rates of evapotranspiration. With the help of EOSDA Crop Monitoring’s weather data, you can schedule precision irrigation and optimally use valuable water resources. Access and analyze past field data, such as precipitation and temperature, on our platform for a better grasp of regional weather trends and strategic planning.

The hourly forecast for the next 14 days includes data on evapotranspiration, radiation, and wind speed and direction in your growing region, allowing you to prevent possible water stress in your crops.

Integrated Weed Control

Cotton plant seedlings grow slowly, making them easy prey for weeds in the early season. If weeds shade and suffocate the seedling, crop productivity can decline dramatically. In contrast, crop leaves shade the ground in the later growing season, which inhibits weed growth. This is why the first two months after planting are a priority for weed control.

Cottonseeds are planted deeply in damp soil using close cultivation or planters, whereas weed seeds are left in the upper, drier soil. Typically, weeds growing in between the rows are managed through the application of herbicides or by cultivation (particularly effective against small weeds). Meanwhile, the sustainable paradigm encourages an integrated approach to weed control, with an emphasis on preventative measures including mulching, crop rotation, and growing cover crops.

The uniform and extensive application of synthetic herbicides to a crop, which is now common, can be both costly and harmful to the environment. The adoption of VRA (variable rate application) technology is essential for minimizing the cost of chemicals for growing cotton and agricultural runoff. EOSDA Crop Monitoring’s ready-made satellite-based vegetation maps serve this purpose. These maps employ vegetation density to segment the field into two to seven zones, with abnormal vegetation zones possibly indicating weed infestation. Once the cause has been located, the same maps can be used to distribute the necessary treatment in a targeted manner.

Preventive Pest And Disease Control

Cotton plant pest insects number over 166, but not all of them are economically significant ^{Rajendran, T. P. et al. (2018, August). Insect Pests of Cotton. In: Pests and Their Management. Omkar (Ed.). Springer. https://doi.org/10.1007/978-981-10-8687-8_11.}. Different pests pose risks at different stages of cotton growth:

• from seedling to fourth leaf emergence: grasshoppers, cutworms, thrips, aphids, and jassids;
• from squaring to bloom: spider mites and plant bugs;
• from bloom to harvest: cotton bollworms, European corn borers, fall armyworms, tobacco budworms, whiteflies, cabbage loopers, stink bugs.

Plants can also be infected by endemic bacteria, fungi, and viruses. Among the most serious crop diseases are anthracnose, Alternaria leaf spot, leaf curl disease, Fusarium and Verticillium wilt, root and boll rot, and bacterial blight.

Most cottonseeds already have insecticides and fungicides applied to them within the scope of a seed treatment strategy, and farmers also apply pesticides in the soil and on the growing crop to get rid of weeds, pathogens, and pests. However, excessive use of chemicals frequently results in leaching, pesticide resistance, disturbance of beneficial microorganisms and insects, and secondary disease and pest outbreaks. This is why early identification of cotton plant pests and diseases, as well as variable rate treatments, are so important in addressing these problems.

For a proactive management approach, the Scouting feature of EOSDA Crop Monitoring facilitates field inspections, especially for large-scale growers. After detecting a trouble area on the vegetation index map, you can promptly assign a task to a scout through our platform. Managers provide detailed instructions for scouts, including precise coordinates and an inspection deadline, and ask for information such as the pest’s name and photos of damaged plants.

The scout can then record observations from the field via the mobile app and submit the report. With this information at hand, you’ll be able to make more informed decisions about how to improve the cotton growing process and prevent a yield decline. The report will be filed away in the field’s history for further review and study.

The Scouting tool is complemented with the Pest and disease risk assessment tool. Simply provide us with the planting date, and our advanced algorithm will empower you with a 14-day risk forecast for the emergence of various plant diseases based on the crop growth stage and the precise weather forecast for your field. Contact our experts at sales@eosda.com to learn more about this powerful risk assessment capability.

How Long Does Cotton Grow?

The typical growing period of cotton is between 140 and 160 days. Although there’s typically a reference to a certain number of days for how fast cotton grows and how long each stage lasts, these are rough estimates that vary based on growing conditions. For example, plants grow faster in high temperatures and slower in low temperatures.

Cotton Harvesting Process

Cotton is ready for harvesting when its bolls open, which typically occurs between midsummer and autumn. Mature plants are particularly vulnerable to the effects of rain, so timely harvesting is essential to protect the crop and maximize yield. Crop success requires dry weather during the cotton harvest season.

The bolls are removed from the stalk using machines known as pickers. Their rotating spindles pick up/twist the seed cotton from the open spelled burrs, and then doffers collect it. A stripper is another mechanical harvesting option. Its rollers with wings and brushes dislodge the open bolls from the branches and onto a conveyor. Both methods involve using airflow to push seed cotton into a basket before emptying it into a boll buggy. Pickers are commonly employed for harvesting long-fiber cotton and strippers for short-fiber.

When cotton is already harvested, the stalks are shredded to prevent insects from overwintering on them. This plant material is left on the field as part of crop residue management aimed at preventing soil erosion.

Effects Of Cotton Growing On The Environment

Despite the industry’s impressive global reach, unsustainable practices in crop growing threaten future output. The following are some of the most detrimental impacts of growing cotton conventionally:

• Eroding and degrading the soil. Monocultural growing is common on cotton farms, which have occupied essentially the same sites for the past 70 years. And like other long-lasting monocultural systems, cotton growing has a devastating impact on soil.
• Polluting ecosystems. The pesticides and fertilizers heavily used on crops seep off of the fields, contaminate water sources, and pollute surrounding ecosystems.
• Global warming. Unfortunately, emitting roughly 220 million metric tons of carbon dioxide each year makes growing cotton far from carbon negative ^{Cotton and the Environment. (2018, July 30). Organic Trade Association.}. Nitrous oxide is 310 times more powerful as a greenhouse gas than carbon dioxide, and its emission into the atmosphere from the regular use of synthetic fertilizers adds to global warming.

It is difficult to bring cotton growing up to environmental standards. However, switching to organic farming and other sustainable practices for growing the crop could hold the key to solving this issue. The ultimate results of this transition will be:

• soil health preserved by manure, mulching, crop rotation, and growing cover crops;
• zero pollution of land and water;
• farm workers and surrounding communities safe from toxic exposures;
• eco-balance and increased biodiversity;
• reduced amounts of greenhouse gas emissions.

EOSDA Crop Monitoring can become your indispensable resource and companion on a journey towards environmental consciousness. Reach out to us for expert guidance on how to implement sustainable agriculture practices in cotton growing.