Cotton

Cotton is a soft, fluffy seed fiber made almost entirely of cellulose. It's grown in a protective capsule, sometimes called a boll, around the seeds of cotton plants in the genus //Gossypium//. Cotton fibers purpose is to aid in seed dispersal. It is often spun into yarn.

Genetically modified (GM) cotton was developed to reduce the heavy reliance on pesticides. The bacterium Bacillus thuringiensis (Bt) naturally produces a chemical harmful only to a small fraction of insects, most notably the larvae of moths and butterflies, beetles, and flies, and harmless to other forms of life. The gene coding for Bt toxin has been inserted into cotton, causing cotton to produce this natural insecticide in its tissues. In many regions, the main pests in commercial cotton arelepidopteran larvae, which are killed by the Bt protein in the transgenic cotton they eat. This eliminates the need to use large amounts of broad-spectrum insecticides to kill lepidopteran pests (some of which have developed pyrethroid resistance). This spares natural insect predators in the farm ecology and further contributes to noninsecticide pest management.

Cotton is the most widely used natural fiber used for clothing. Cost of production significantly decreased with invention of cotton gin. Cotton can be grown organically, which is more environmentally friendly. To be certified organic, the farm on which the cotton is grown must have followed certain organic standards for at least three years. Cotton production, in general, is not very environmentally friendly. It normally requires the use of many agricultural chemicals. From irrigation to dyeing, cotton requires lots of water to be grown and produced correctly. Dyes and finishing chemicals are very harmful for the environment and cotton normally needs both of these things to be aesthetically pleasing and to have the ability to be sold, especially as clothing.

=** Can you eat a cotton T-shirt? ** Since cotton contains starch the question on whether or not you can eat your own cotton shirt has been asked by many. The answer is no. Yes, although the human body can digest glucose it cannot digest cellulose due to the structure. Digestibility of glucose is based on the links between the molecules. If the link between two glucose molecules is an alpha acetyl link then it is digestible and is able to be absorbed by the human body. If the link is a beta acetyl link then it is cellulose and is not digestible by humans. A cotton shirt is made mostly of cellulose and therefore you can not digest it or gain any nutrition from it if you ingested it. = = = There are four commercially-grown species of cotton, all domesticated in antiquity:
 * Major producers:** US, Cina, India, Egypt and Pakistan
 * Cotton-classification:** Can be done by hand or machine;relates to fiber quality and character.
 * **Quality**: Length, strength, fineness, convolution, maturity, color and absence of impurities
 * **Character**: Maturity, smoothness and uniformity.
 * Cotton Lengths:**
 * Length-** Genetic characteristic depends upon the type planted.
 * Short staple- 0.38 to 0.75 inches
 * Intermediate staple- 0.81 to 1.35 inches
 * Long staple- 1.5 to 2.5 inches
 * Longer staples are associated with finer fibers
 * Cotton chemical composition**
 * 99% cellulose
 * Hydroxyl units
 * sensitive to damage by bleaches and acids
 * Cotton Characteristics**
 * absorbent (hydrophilic)
 * good heat and electrical conductor
 * heat resistant
 * convolutions are present and seen under a microscope
 * //Gossypium Hirsutum// – upland cotton, native to Central America, Mexico the Caribbean and southern Florida, (90% of world production)
 * //Gossypium barbadense// – known as extra-long staple cotton, native to tropical South America (8% of world production)
 * //Gossypium arboreum// – tree cotton, native to India and Pakistan (less than 2%)
 * //Gossypium herbaceum // – Levant cotton, native to southern Africa and the Arabian Peninsula (less than 2%)

The two New World cotton species account for the vast majority of modern cotton production, but the two Old World species were widely used before the 1900s. While cotton fibers occur naturally in colors of white, brown, and green, fears of contaminating the genetics of white cotton have led many cotton-growing locations to ban growing of colored cotton varieties which remain a specialty product.

**Insect Resistant Cotton Plants** Frederick J. Perlak1, ,*, Randy W. Deaton1, Toni A. Armstrong1, Roy L. Fuchs1, Steven R. Sims1, John T. Greenplate1 & David A. Fischhoff1

Abstract
We have expressed truncated forms of the insect control protein genes of //Bacillus thuringiensis// var. //kurstaki// HD-1(//cryIA(b)//) and HD-73 (//cryIA(c)//) in cotton plants at levels that provided effective control of agronomically important lepidopteran insect pests. Total protection from insect damage of leaf tissue from these plants was observed in laboratory assays when tested with two lepidopteran insects, an insect relatively sensitive to the //B.t.k//. insect control protein, //Trichoplusia ni//(cabbage looper) and an insect that is 100 fold less sensitive,//Spodoptera exigua// (beet armyworm). Whole plants, assayed under conditions of high insect pressure with //Heliothis zea// (cotton bollworm) showed effective square and boll protection. Immunological analysis of the cotton plants indicated that the insect control protein represented 0.05% to 0.1% of the total soluble protein. We view these results as a major step towards the agricultural use of genetically modified plants with insect resistance in this valuable, high acreage crop.

Organic production
Organic cotton is generally understood as non GMO cotton, that is certified to be grown without the use of any synthetic agricultural chemicals, such as fertilizers or pesticides. Its production also promotes and enhances biodiversity and biological cycles. United States cotton plantations are required to enforce the National Organic Program (NOP). This institution determines the allowed practices for pest control, growing, fertilizing, and handling of organic crops. As of 2007, 265,517 bales of organic cotton were produced in 24 countries, and worldwide production was growing at a rate of more than 50% per year.


 * History **

Cotton was first cultivated around 7,000 years ago by the inhabitants of western Pakistan, for example as the site of Mehrgarh where early cotton thread has been preserved in copper beads.[4home] Cotton cultivation became more widespread during the Indus Valley Civilization, which covered a huge swath of the northwestern part of the South Asia, comprising today parts of eastern Pakistan and northwestern India.[5home] The Indus cotton industry was well developed and some methods used in cotton spinning and fabrication continued to be used until the modern industrialization of India.[6home] Between 2000 and 1000 BC cotton became widespread in much of India.[7home] For example, it has been found at the site of Hallus in Karnataka around 1000 BC. Well before the Common Era, the use of cotton textiles had spread from India to the Mediterranean and beyond.[8home]



Cotton is a completely cellulose fiber that is made into several different apparel including T-shirts, shorts, sweaters, and several other textiles. Cotton grows in different lengths and different styles depending on the region the fiber grows in. Cotton producing farms often are affected by several different types of pests that actually get into the seed during harvesting. Cotton is also one of the oldest crop that has been cultivated, but today several other synthetic forms of cotton-feeling textiles are available which makes stiff competition for cotton to stay prominent in the market.