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Gossypium hirsutum L.

Syn.: Gossypium mexicanum Tod.
Malvaceae
American upland cotton

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Toxicity
  5. Description
  6. Germplasm
  7. Distribution
  8. Ecology
  9. Cultivation
  10. Harvesting
  11. Yields and Economics
  12. Energy
  13. Biotic Factors
  14. Chemical Analysis of Biomass Fuels
  15. References

Uses

Cultivated primarily for its vegetable seed fiber, the raw material for a large volume of textile products, this species is considered the most important of the cotton-yielding plants, providing the bulk of commercial cottons. Linters are of intermediate texture and shorter than those of G. barbadense. Seeds yield a semi-drying and edible oil, used in shortening, margarine, salad and cooking oils, and for protective coverings. Residue, cottonseed cake or meal is important protein concentrate for livestock. Pigg (1980) reports that bread, made with cottonseed protein is an even better source of protein than enriched white bread, six slices of which provide 20% of the adult RDA. Low-grade residue serves as manure, bedding and fuel. Fuzz, which is not removed in ginning, become linters in felts, upholstery, mattresses, twine, wicks, carpets, surgical cottons, and in chemical industries such as rayons, film, shatterproof glass, plastics, sausage skins, lacquers, and cellulose explosives.

Folk Medicine

Cottonseed and roots have been used in nasal polyps, uterine fibroids and other types of cancer (Hartwell, 1967–1971). Gossypol has shown anticancer activity in the new LL, WA and PS-150 tumor systems. Mucilaginous tea of fresh or roasted seeds used for bonchitis, diarrhea, dysentry, and hemorrhage. Flowers diuretic and emollient, used for hypochondriasis. Leaves steeped in vinegar applied to the forehead for headache. Often used by early American slaves for abortion; apparently with no serious side effects. In Guinea, leaves and seeds considered emollient and roots emmenagogue. About 100 g root was boiled in about a liter of water until reduced by 1/2. Fifty g of the resultant witches brew was then drunk about every half hour. Root decocotion used for asthma, diarrhea, and dysentery. Root bark, devoid of tannin, astringent, antihemorrhoidal; used as an emmenagogue, hemostat, lactagogue, oxytocic, parturient, and vasoconstrictor. Gossypol is being used in China as a male contraceptive.

Chemistry

Root bark contains ca 3% of a reddish acidic resin, a volatile oil, a phenolic acid (probably 2,3-dihydrobenzoic acid; salicylic acid, a colorless phenol, betaine, a fatty alcohol, a phytosterol (C27H46O), a hydrocarbon (probably triacontane), ceryl alcohol and oleic and palmitic acid. Hager's Handbook (List and Horhammer, 1969–1979) also lists isoquercitrin, quercimeritrin, quercetin-3'-glucoside, hirsutrin, isoastragalin, palmitic acid, oleic acid, linoleic acid, a-pinene, b-caryophyllene, bisabolol, caryophyllenepoxide, bisabolenoxide, abscissin II, serotonin, chrysanthemin, gossypicyanin, and histamine.

Toxicity

Gossypol, the toxic dihydroxyphenol, occuring in seeds and the glands of seedlings, must be removed before cottonseed can be used for feed. Hogs have died from eating raw seed (Morton, 1974). Per 100 g, the ground seed is reported to contain 7.3 g H2O, 23.1 g protein, 22.9 g fat, 43.2 g total carbohydrate, 16.9 g fiber, 3.5 g ash, 140 mg Ca, 1.2 mg Mn, 320 mg Mg, 680 mg P, 14 mg Fe, 290 mg Na, 1,110 mg K 240 mg S, 5 mg Cu. Once the oil is removed, the meal contains per 100 g, 7.3 g H2O, 41.4 g protein, 5.6 g fat, 10.9 g crude fiber, 39.5 g total carbohydrate (6.5 g total sugars, 6.4% lignin), 190 mg Ca, 1.8 mg Cu, 10 mg Fe, 490 mg Mg, 2.3 mg Mn, 1,090 mg P, 1,250 mg K, 50 mg Na, and 400 mg S (Parnell, 1981). Commercial cottonseed contains approximately 92% dry matter, 16–20% protein, 18–24% oil, 30% carbohydrates, 22% crude fiber. After ginning, cottonseed includes unginned lint, fuzz, 16% crude oil, 45.5% cake or meal, 25.5% hulls, and 8% linters. Principal pigment in seed is gossypol, a poisonous phenolic compound usually rendered harmless on crushing or heating, but may retain minute amounts to which pigs and chickens are sensitive.

Description

Annual subshrub, up to 1.5 m tall; branches of two kinds: vegetative and fruiting; leaves alternate, petiolate, palmately 3–5-lobed, hirsute, blade cordate, as broad as long, 7.5–15 cm across; flowers 6–8 on each fertile branch, large, white or yellow, subtended by a reduced calyx and 3–4 large green fringed bracts; staminal column surrounding style made up of 100 or more stamens; ovary superior, 3–5-carpellate; fruit a dehiscent capsule, 4–6 cm long, spherical, smooth, light green, with few oil glands; seeds 1 cm long, ovoid, dark brown, about 36 per fruit, bearing hairs of two kinds on the epidermis: long fibers called lint and short fibers strongly attached to seedcoat called fuzz; weight of 100 seeds 10–13 g; well-developed taproot with numerous laterals penetrating as deeply as 3 m. Fl. variable as to locality, approx. 3 months after planting.

Germplasm

Reported from the Middle American, South American, and African Centers of Diversity, upland cotton, or cvs thereof is reported to tolerate bacteria, disease, drought, fungus, hydrogen floride, high pH, insects, low pH, nematodes, photoperiod, sand, virus and waterlogging (Duke, 1978). Authors recognize seven entities or botanical varieties: palmeri, morilli, richmondi, vucatanense occurring wild on coastal dunes in Central America, and marie-galante, punctatum, and latifolium, these latter forms being known as Upland Cotton, forming the basis of much of the world's commercial cotton. Hundreds of cultivars are known; 'Auburn 56', 'Bayou', 'Auburn 623 RNR' and 'Darminii' being resistant to rootknot nematode, Meloidogyne incognita. Varieties are sometimes classed according to fiber length, as: Long Staple, 'Acala' cultivars; Medium Staple, 'Deltapine' and 'Coker 100 Wilt', and Short Staple, 'Lankart'. G. hirsutum is an allopolyploid containing one set of chromosomes homologous with Old World linted cottons (Genome A) and one set of homologous with a New World wild species (Genome D). Cytoplasmic male sterility has not yet been found, but gametocides are being developed which prevent pollen development in some cultivars. (2n = 52)

Distribution

Believed to have originated in Central America. In its transition from tropical to temperate regions, American Upland Cotton has lost the perennial, short-day habit to become highly vegetative producing few or no fruiting branches when grown during long days. Annual forms were developed in which all periodicity controls were lost. American Upland Cotton was taken from Mexico to United States about 1700. During American Civil War, it was introduced into most tropical and subtropical countries of the world. It now forms basis of all commercial cotton crops of Africa outside the Nile Valley, all those of South America except in Peru and northern Brazil, of the modern Russian crop, and much of that of northern India and Pakistan, and the Philippine Islands, as well as that of the Cotton Belt of the United States. Upland and Cambodian varieties are invading the Chinese crop, and where these cottons are developed in southeast Asia, they will be based on these types and hybrids between them.

Ecology

Ranging from the Cool Temperate Moist to Wet through Tropical Very Dry to Moist Forest Life Zones, Upland Cotton is reported to tolerate annual precipitation of 2.9 (irrigated) to 27.8 dm (mean of 36 cases = 11.3), annual temperature of 7.0 to 27.8°C (mean of 36 cases = 20.7), and pH of 4.5 to 8.4 (mean of 31 cases = 66). In the Northern Hemisphere, cotton production extends to 37°N in the United States, 47°N in Soviet Union, and 42°N in Manchuria. In the Southern Hemisphere, the limits are 32°S in South America and Australia, and to about 30°S in Africa. Sensitive in any stage to frost, cotton limits are set by the early and late frosts. Cotton is crop of warm plains, grown commercially from sealevel to 1,200 m, with some perennial forms found at 1,800 m. A long-season plant, cotton requires a minimum of 180–200 frost-free days of uniformly high temperatures, averaging 21–22°C. Full sunlight is critical for proper development. Where rainfall is less than 500 mm annually, irrigation should be practiced. Amount of rainfall is not as important as when it falls. Heavy rains injure plants. Moderate rainfall is preferable during vegetative growth followed by a dry period to allow the bolls to mature and be picked. Cotton is tolerant of a wide variety of soils, but thrives best on deep, friable, moisture-holding soils with good humus supply. Optimum pH is 5.2–7. In India, cotton is grown on black alluvial and red soils; in USSR, major crop grown on alluvial soils; in Ukraine, on hernozem soils; and in Egypt, on alluvial soils along Nile River.

Cultivation

Seeds of some cultivars require a 2–3 month period of dormancy. Seeds lose viability quickly under moist conditions. Commercial cotton is always grown from seed, sown when soil temperatures are at least 18°C. Seed sown in drills or in hills. The hill-drop method is perhaps best if hand-hoe labor is used. Plant 2.5 cm deep under normal conditions. Seed rate of 17–28 kg/ha gives a good stand with 75,000–150,000 plants/ha, allowing for some losses. Row width of 100 cm is most suitable for mechanization. Seedbed preparation should include eradication of residue from past crops, maintenance of drainage, good tilth, elimination of hardpans, control of weeds and pests. Periodic cultivation and weeding is practiced. Chemical herbicides are routine in many countries. Insect control is one of the most costly items. Pre- and post-planting pesticide application is practiced. Irrigation is used when soil moisture is inadequate or when soil is poor in moisture-holding ability. An increasing amount of cotton is grown under irrigation yearly. Fertilizers are also a major item; for large harvests nutrients must be continually replaced. Amounts depend on soils; local agents should be consulted. Rotation is a recommended practice. Short rainy seasons often allow only the single crop to be grown. Where possible, a rotation of fallow, wheat, fallow, peas, cotton, fallow has proved practical.

Harvesting

Planting to flowering is 80–110 days with another 55–80 days until the boll opens. Hand-harvesting still accounts for the largest percentage of harvest in spite of advances in mechanization. Hand methods provide a higher grade of cotton and gets more from the fields. One man can pick about 50–110 kg of seed cotton per day. On the average a two-row mechanical picker can harvest 1,400 kg of seed cotton per hour. Proper ginning is important in determining the quality of the fiber and the price. Seed removal is done almost exclusively by one of many ginning processes on the market today. After linters and fuzz have been removed from seed, the oil is expressed.

Yields and Economics

Pryde and Doty (1981) put the average oil yield at only 140 kg/ha. According to Parnell (1981), annual U.S. cottonseed yields are 800–950 kg/ha. About 6–8% is planted, with small quantities used for feed; the remainder is crushed for cottonseed oil (ca $0.45/kg in April, 1982), with the byproduct being cottonseed meal (ca $145/ton). A metric ton of cottonseed yields ca 160 kg oil, 450 kg meal, 68 kg linters, 250 kg hulls, and 72 kg trash, waste, and invisible losses (Parnell, 1981). The world low production yield figure was 73 kg/ha in Grenada, the international production yield was 1,251 kg/ha, and the world high production yield was 3,306 in Guatemala. (FAO, 1980a) Average lint yield varies, ranging from 112 kg/ha in rainfed cottons in India to 3,360 kg/ha in irrigated cotton lands of California. More typically, the average in Egypt is 620 kg/ha, 784 kg/ha in Mexico, and 280 kg/ha in Thailand. Cotton fiber is one of the most important fiber products in the world. Major exporting countries are United States (3.15 billion kg), China (1.35 billion kg), USSR (1.35 billion kg), India (0.9 billion kg), Egypt (0.45 billion kg), and Mexico (1.45 billion kg), based on 1960 figures. Major importing countries are Japan, West Germany, France, United Kingdom, and Italy. Cotton seed world production for 1970 was 22,066,000 MT on 33,186,000 ha, giving an average yield of 660 kg/ha. Cotton seed prices, based on 1969 producer prices ranged from 1.5cents/kg in UAR to 4.5cents/kg in U.S. Wholesale price in India was 11.9cents/kg, and the import price was 9.1cents/kg. Cottonseed oil production in United States for 1970 was 2,012,900 MT, which was 7% of the market, with wholesale prices in United States 24.0cents/kg; import prices in Europe were about 30.3cents/kg. As of June 15, cottonseed oil was $0.265/lb., compared to peanut oil for $0.38, poppyseed oil for $1.39, tung oil for $0.65, linseed oil for $0.33, coconut oil for $0.275, corn oil for $0.232, soybean oil for $0.21 (Chemical Marketing Reporter, June 15, 1981). At $2.00 per gallon, gasoline is roughly $0.25/lb.

Energy

The harvest index of seedcotton is 1:2, i.e. for each kg of seedcotton, there is about 2 kg aerial biomass residue. In some countries (e.g. Turkey, Russia), even this is used for fuel. The residue coefficient, defined as the ratio of the weight of dry matter of residue to recorded harvested weight, ranges from 1.20 to 3.00 (assuming both lint and seed are included in production). Upper limits were determined by USDA experts (NAS, 1977a). Vaing and Delille (1983) report on a modified 25-HP tractor used in Mali which ran on cotton stalks (6.3–11.8 Kg /hr). Seedcotton is the usual production and yield unit. Of the seedcotton, almost nothing is truly wasted, usually 1/3 is lint, and 2/3 is seed (with ca 20% oil, 20% protein). About 5% is called linters, the so-called short fibers or fuzz, which is almost pure cellulose acetate. Another 5% is seed coat, which contains ca 7% raffinose. The hulls (ca 5%) are ground up and used for fertilizer or filler. Noting that diesel fuel energy accounted for 10–24% of total energy required for growing and harvesting cotton, fertilizer for 50–65% and pesticides for 19–28%, Sistler and Smith (1981) concluded "There are many gocd reasons to reduce tillage in cotton, but saving energy may not be one of them if the operator has to be replaced with a high energy pesticide."

Biotic Factors

Chan et al. (1978) reported on a condensed tannin (molecular weight 4,850) that was a major antibiotic component (against Heliothis virescens) comprising 3.4% of the dried flower buds. At 0.2% in the diet, the condensed tannin retarded larval growth by 84%. Fungi known to cause diseases in cotton include the following: Aecidium desmium, A. gossypii, Alternaria gossypina, A. humicola, A. macrospora, A. tenuis, Arthrobotrys superba, Ascochyta gossypii, Aspergillus niger, A. flavus, A. fumigatus, A. glaucus, A. luchuensis, A. nidulans, A. ochraceus, A. penicilloides, A. repens, A. ustus, A. versicolor, Botryosphaeria ribis, Cephalosporium acremonium, Cephalothecium roseum, Cercospora althaeina, C. gossypina, Choanephora conjuncta, Ch. cucurbitarum, Cladosporium herbarum, Colletotrichum gossypii, Diplodia gossypina, Discosphaerella phaeochlorina, Epicoccum purpurascens, Eremothecium ashbyii, Fusarium anguioides, F. coeruleum, F. concolor, F. culmorum, F. equiseti, F. moniliforme, F. oxysporum, F. semitectum, F. solani, F. vasinfectum, Gibberella fujikuroi, Glomerella gossypii, Helicobasidium purpureum, Helminthosporium gossypii, Hendersonia sarmentorum, Humicola fusco-atrata, Hypochnus aderholdii, Hyponectria gossypii, Kuehneola desmium, Leptosphaeria spp., Leveillula malvacearum, L. taurica, Macrophomina phaseoli, Macrosporium gossypii, Memnoniella echinata, Monilia crassa, M. sitophila, Mucor racemosa, Mycosphaerella areola, M. gossypii, Myrothecium verrucaria, Nectria cinnabarina, Nematospora coryli, N. gossypii, Neocosmospora vasinfecta, Neurospora sitophila, Nigrospora gossypii, N. oryzae, N. sphaerica, Ozonium auricomum, O. texanum, Pellicularia filamentosa, Penicillium glaucum, Pestalotia gossypii, Pestalozziella gossypina, Phakospora desmium, Ph. gossypii, Phlyctaena gossypii, Phoma corvina, Ph. gossypii, Phomopsis malvacearum, Phyllosticta gossypina, Ph. malkoffii, Phymatotrichum omnivorum, Physalospora rhodina, Phytophthora parasitica, Pleospora nigricantia, Puccinia stakmanii, Pullularia pullulans, Pythium aphanidermatium, P. debaryanum, P. ultimum, Ramularia areola, Rhinotrichum macrosporum, Rh. tenellum, Rhizoctonia aderholdii, Rh. solani, Rhizopus stolonifer, Schizophyllum, commune, Sclerotium rolfsii, Septoria gossypina, Stachybotrys atra, S. lobulata, Thielaviopsis basicola, Trichoderma viride, Trichothecium roseum, Valsa gossypina, Verticillium albo-atrum, V. dahliae. Bacterial disease isolated from cotton include: Aerobacter closacea, Agrobacterium tumefaciens, Bacillus gossypina, Xanthomonas malvacearum. Virus isolated from this cotton include: Abutilon mosaic, Anthocyanosis, Brazilian tobacco streak, Enation mosaic, Euphorbia mosaic, Leaf curl, and Red-leaf droop. Striga asiatica (S. lutea) parasitizes the plant. Some ailments of cotton are due to deficiencies of Ca, K, or Mg, others due to Mn toxicity. Many nematodes attack cotton, and developing nematode-resistant varieties of cotton is very important. Some of those isolated from cotton are: Aphelenchus avenae Belonolaimus gracilis, B. longicaudatus, Criconemella ornata, C. rustica, C. sphaerocephala, Discolaimus paraconura, Helicotylenchus cavenessi, H. dihysteria, H. mycrocephalus, H. microlobus, H. pseudorobustus Hoplolaimus galeatus, H. seinhorsti, H. paraobustus, H. tylenchiformis, Hemicyliphora membranifer, Meloidogyne arenaria, M. thamesii, M. hapla, M. incognita, M, incognita acrita, M. javanica, Merlinius brevidens, Pratylenchus brachyurus, P. coffeae, P. delattrei, P. pratensis, P. vulnus, Rotylenchus reniformis, Scutellonema clathricaudatum, S. bradys, Trichodorus chistei, Tylenchorrhynchus annulatus, T. claytoni, T. dubius, T. martini, Xiphinema americanaum, X. indicum, X. ifacolum, and X. insigne. The Boll weevil (Anthonomus grandis) is the most, destructive of the insects attacking cotton. Other insect pests include: Cotton aphid (Aphis gossypii), Cotton leaf-perforator (Bucculatrix thurberiella), Thrips (Frankliniella occidentalis), and Bollworms (Heliothis zea and H. virescens).

Chemical Analysis of Biomass Fuels

Analysing 62 kinds of biomass for heating value, Jenkins and Ebeling (1985) reported a spread of 16.42 to 15.35MJ/kg, compared to 13.76 for weathered rice straw to 23.28 MJ/kg for prune pits. On a % DM basis, the gin trash contained 67.30% volatiles, 17.60% ash, 15.10% fixed carbon, 39.59% C, 5.26% H, 36.38% O, 2.09% N, and undetermined residue.

References

Complete list of references for Duke, Handbook of Energy Crops
Last update Wednesday, January 7, 1998 by aw