Gossypium
- For information on cotton production, industry, history, and applications, see cotton.
- For the clothing company, see Gossypium (clothes).
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Gossypium (ancient name of the cotton plant). Malvaceae. Cotton. Perhaps thirty or more species of herbs and shrubs of warm countries, although more than 100 have been described; some authorities reduce them to about three. They are grown for the fiber that is borne on the seeds. See Co/ton. They are scarcely horticultural subjects, and therefore are not treated fully in this work.
Gossypiums are tall stout herbs, or tree-form bushes: lvs. large, alternate, petiolate, mostly prominently 3-9-lobed but sometimes entire: fls. white, yellow or purplish, provided with 3-5 large cordate calyx-like bracts; calyx entire or somewhat 5-lobed; stamens united into a column; ovary 3-5-celled, each cell 3-11- ovuled; style 3-5-lobed: fr. a loculicidally dehiscent caps., bearing seeds that are obovate, rounded or slightly angular, sometimes smooth, but usually covered with a short down or fuzz and a longer coat of brown, creamy or white hairs, called the lint.
The cottons of commerce belong, according to Lewton, to about eight distinct botanical types and may be divided into two main groups, the New World and the Old World cottons. The New World group includes American Upland cotton (G. hirsutum, Linn.); Sea Island and Egyptian cottons (G. barbadense, Linn.); and the tropical tree cottons of South America (G. brasiliense, Macf. and G. peruvianum, Cav.). The Old World cottons include the Levant cotton (G. herbaceum. Linn.), cultivated in southern Europe and western Asia; the oriental tree cotton (G. arboreum, Linn.), with yellow or purple-red flowers; the common cotton of India (G. neglectum, Todaro); and the Chinese and Japanese cottons (G. nanking, Meyen.).
Cotton (probably G. herbaceum) was grown in gardens in Delaware and Maryland in colonial times as an ornamental plant.
Two species have been offered as ornamental plants. G. davidsonii, Kellogg, from Lower Calif, and Cerros Isls., woody, with handsome yellow fls. purple at the base, 1 in. long, and small cordate mostly entire lvs. G. sturtii, F. Muell., endemic in interior of Australia: shrub, several feet high, more or less marked with black dots: lvs. broadly ovate, entire, 1-2 in. long, glaucous: fls. large, purple with dark center; bracts to 1 in. long, cordate, entire, many-nerved, black-dotted. The common fiber-cottons are sometimes planted in northern gardens for curiosity, but they seldom make attractive plants where the nights are cool; sometimes they are seen in warm glasshouses, with other economic plants- L. H. B.
Gossypium is a genus of 39-40 species of shrubs in the family Malvaceae, native to the tropical and subtropical regions of both the Old World and the New World. The cotton plants, sources of commercial cotton fabric, are included in this genus.
Cotton shrubs can grow up to 3 m (10 ft) high. The leaves are broad and lobed, with three to five (or rarely seven) lobes. The seeds are contained in a capsule called a boll, each seed surrounded by downy fibres called lint. Commercial species of cotton plant are G. hirsutum (90% of world production), G. barbadense (8%), G. arboreum and G. herbaceum (together, 2%). While the lint (fiber) naturally occurs in colors of white, brown, and green, fears of contaminating the genetics of white cotton has led many cotton-growing locations to ban growing of coloured cotton varieties.
Species of Gossypium
- Commercial cotton species
Commercial cotton fibres, used to manufacture cloth, are derived from the fruit of the cotton plant. The following species are grown commercially:
- Gossypium arboreum L. – Tree cotton, native to India and Pakistan.
- Gossypium barbadense L. – known as American Pima, Creole, Egyptian, or Sea island cotton, native to tropical South America.
- Gossypium herbaceum L. – Levant cotton, native to southern Africa and Arabian Peninsula.
- Gossypium hirsutum L. – Upland cotton, native to Central America, Mexico, the Caribbean and southern Florida - most commonly grown species in the world.
- Non-commercial species
- Gossypium australe F.Muell – Endemic to north-western Australia
- Gossypium darwinii - Darwin's cotton, found only on the Galapagos Islands
- Gossypium sturtianum J.H. Willis – Sturt's Desert Rose, native to Australia.
- Gossypium thurberi Tod. – Arizona wild cotton, native to Arizona and northern Mexico.
- Gossypium tomentosum Nutt. ex Seem – Ma‘o or Hawaiian cotton, endemic to the Hawaiian Islands.
Many varieties of cotton have been developed by selective breeding and hybridization of the above species. Experiments are ongoing to cross-breed various desirable traits of wild cotton species into the principal commercial species, such as resistance to insects, disease and drought-tolerance.
Cotton pests and diseases
Pests
- Boll weevil, Anthonomus grandis
- Cotton aphid, Aphis gossypii
- Cotton stainer, Dysdercus Koenigii
- Cotton bollworm, Helicoverpa armigera and native budworm Helicoverpa punctigera are caterpillars that damage cotton crops.
- Some other Lepidoptera larvae also feed on cotton - see list of Lepidoptera which feed on Cotton plants.
- Green mirid (Creontiades dilutus), a sucking insect
- Spider mites, Tetranychus urticae, T. ludeni and T. lambi
- Thrips, Thrips tabaci and Frankliniella schultzei
Diseases
- Alternaria leaf spot, caused by Alternaria macrospora and Alternaria alternata
- Anthracnose boll rot, caused by Colletotrichum gossypii
- Black root rot, caused by the fungus Thielaviopsis basicola
- Blight caused by Xanthomonas campestris pv. malvacearum
- Fusarium boll rot caused by Fusarium spp.
- Phytophthora boll rot, caused by Phytophthora nicotianae var. parasitica
- Sclerotinia boll rot, caused by fungus Sclerotinia sclerotiorum
- Stigmatomycosis, caused by the fungi Ashbya gossypii, Eremothecium coryli (Nematospora coryli) and Aureobasidium pullulans
See also
External links
Gossypium hirsutum flower with bumblebee pollinator, Hemingway, South Carolina
Integrated Pest Management bollworm trap at a cotton field in Manning, South Carolina
Natural biocontrol: Predatory Polistes wasp looking for bollworms or other caterpillars on cotton plant in Hemingway, South Carolina