Cotton is a globally significant agricultural commodity, providing the natural fiber used in countless textiles worldwide. This staple fiber develops in a protective case called a boll around the seeds of the Gossypium plant, a member of the mallow family. Composed primarily of cellulose, cotton fiber is prized for its breathability, durability, and versatility in fabric manufacturing. Growing cotton is a complex, multi-stage process that requires careful management and specific environmental conditions.
Preparing the Field and Planting
Cotton cultivation demands a long, hot, and frost-free growing season, ideally lasting 160 to 180 days. The plant thrives in warm climates, with optimal air temperatures ranging between 70 and 100 degrees Fahrenheit during active growth. Cotton prefers deep, well-drained loamy soils, which allows the plant’s deep taproot to develop fully.
Soil preparation often starts in the fall following the previous harvest, with farmers incorporating crop residue back into the soil to improve moisture retention and add nutrients. Modern farming often utilizes minimum-tillage or strip-tillage techniques, which disturb the soil less than traditional plowing and help the ground warm up faster in the spring.
Farmers choose specific cultivars, such as Upland cotton or the longer-staple Pima cotton, based on regional climate and soil characteristics. Planting must be timed precisely, requiring the soil temperature at a two-inch depth to be at least 65 to 68 degrees Fahrenheit for a few consecutive days. Seeds are typically planted shallowly, between 0.5 and 1.5 inches, to conserve the young plant’s energy. Precision planters place the seeds uniformly, aiming for a final stand of about two to three plants per foot of row.
Managing Growth: From Seedling to Boll
Seedlings emerge within four to fourteen days after planting. Around 35 days after emergence, the plant enters its reproductive stage, forming tiny flower buds known as squares. These squares take approximately 20 to 25 days to mature into flowers, marking a period where the plant is vulnerable to water stress and pests.
Following the squaring phase, the plant begins to flower, producing creamy-white, hibiscus-like blooms that last for only a day before turning pink and dropping off. Once pollinated, the flower gives way to the boll, the structure where the fibers develop. The boll development phase is the longest, taking 50 to 60 days to full maturity, and is when the plant’s nutrient and water requirements peak.
Water management is finely tuned during this period, as cotton is a thirsty crop often requiring irrigation to supplement rainfall. Irrigation scheduling is important, with water applications timed to avoid square and boll shedding caused by drought stress. Nutrient management, including nitrogen for vegetative growth and potassium for boll fill and fiber quality, is often split-applied to match the plant’s increasing demand.
Pest management is essential in cotton farming. Historically, insects like the boll weevil laid eggs in the squares and bolls, causing them to drop off. While the boll weevil has been largely eradicated in the United States through integrated pest management programs, continuous monitoring and targeted insecticide applications remain important strategies. Modern crop protection also involves promoting plant health through balanced nutrition.
Harvesting and Initial Processing
The growth cycle ends when the bolls naturally split open, revealing the fluffy white fiber in a process called boll opening. Harvest typically occurs between 150 and 160 days after planting, once enough bolls have opened. This often follows the application of a defoliant to remove the leaves and prepare the plant for mechanical harvesting. Two main mechanized methods are used.
Cotton pickers use rotating spindles to gently twist the lint from the open boll, allowing for multiple passes as bolls ripen. This method is favored for high-quality cotton because it removes less foreign matter, such as leaf trash and burrs. Cotton strippers use brushes or rollers to forcefully remove the entire boll, including the burr and plant material. Strippers are faster and more affordable but result in a product with more debris.
Once harvested, the raw material, known as seed cotton, is compressed into large modules and transported to a cotton gin. Ginning is the first stage of processing, mechanically separating the lint (fiber) from the seeds and debris. Modern saw gins use fast-moving circular saws to pull the fiber through narrow slots, while roller gins are used for the longer, more delicate fibers of Pima cotton. The cleaned lint is then compacted into dense, standardized bales weighing about 480 to 500 pounds, ready for shipping to textile mills.