Source: Magness et al. 1971
Cotton is grown primarily for the fibers or lint, but the oil containing seeds are highly important. World production of cotton seed oil averaged 2,673,000 tons, 1964-66. The cotton plant is a stiff growing herbaceous annual outside the tropics, with fairly large, lobed leaves. The fruits are capsules which dehisce as they ripen. Each capsule contains up to 40 or 50 obovate, rounded or angular seeds, to which are attached the fibers or lint. The lint and seeds are harvested from the dehiseed bolls, partly by hand but now largely by machine in the U.S. The longer lint is removed from the seeds mechanically at cotton gins, then baled. The seeds of most varieties are still covered with short fibers or linters after the ginning. The seeds consist about half of hull and half of kernel. The kernels contain 28 to 40 percent oil. In extracting the oil the seeds are cleaned, delinted, and pressed or put through expellers either whole or after dehulling. A ton of seeds yields around 300 pounds of oil. The meal or press cake is a valuable high-protein livestock feed and the cotton fields, after the harvest, may be used for livestock pasturage. The oil is used mainly for shortenings. Smaller quantities are used for cooking and salad oils, margarines, and soap manufacture.