Cotton

Cotton is a fiber obtained from various species of plants, genus Gossypium, family Malvaceae (Mallow), and is the most important and widely used natural fiber in the world. Cotton is primarily an agricultural crop, but it can also be found growing wild. Originally cotton species were perennial plants, but in some areas cotton has been selectively bred to develop as an annual plant. There are more than 30 species of Gossypium, but only four species are used to supply the world market for cotton. Gossypium hirsutum, also called New World or upland cotton, and G. barbadense, the source of Egyptian cotton and Sea Island Cotton, supply most of the world's cotton fiber. G. barbadense was brought from Egypt to the United States around 1900. A hybrid of these two cotton species known as Pima cotton, is also an important source of commercial cotton. These species have relatively longer fibers and greater resistance to the boll weevil, the most notable insect pest of cotton plants. Asian cotton plants, G. arboreum and G. herbaceum grow as small shrubs and produce relatively short fibers. Today, the United States produces one-sixth of the world's cotton. Other leading cotton producing countries are China (the world's biggest producer), India, Pakistan, Brazil, and Turkey. The world production of cotton in the early 1990s was about 18.9 million metric tons per year. The world's largest consumers of cotton are the United States and Europe.

For centuries, harvesting was done by hand. Cotton had to be picked several times in the season because bolls of cotton do not all ripen at the same time. Today, most cotton is mechanically harvested. Farmers wait until all the bolls are ripe and then defoliate the plants with chemicals, although sometimes defoliation occurs naturally from frost.