Cotton

Mehrgarh shown in a physical map of the surrounding region.

The earliest evidence of the use of cotton in the Old World, dated to 5500 BC and preserved in copper beads, has been found at the Neolithic site of Mehrgarh, at the foot of the Bolan Pass in Balochistan, Pakistan.[9][10][11]

Cotton bolls discovered in a cave near Tehuacán, Mexico, have been dated to as early as 5500 BC, but this date has been challenged.[12] More securely dated is the domestication of Gossypium hirsutum in Mexico between around 3400 and 2300 BC.[13]

In Peru, cultivation of the indigenous cotton species Gossypium barbadense has been dated, from a find in Ancon, to c. 4200 BC,[14] and was the backbone of the development of coastal cultures such as the Norte Chico, Moche cultureMoche, and Nazca. Cotton was grown upriver, made into nets, and traded with fishing villages along the coast for large supplies of fish. The Spanish who came to Mexico and Peru in the early 16th century found the people growing cotton and wearing clothing made of it.

The Greeks and the Arabs were not familiar with cotton until the Wars of Alexander the Great, as his contemporary Megasthenes told Seleucus I Nicator of "there being trees on which wool grows" in "Indica". This may be a reference to "tree cotton", Gossypium arboreum, which is a native of the Indian subcontinent.

According to the Columbia Encyclopedia:[15]

Cotton has been spun, woven, and dyed since prehistoric times. It clothed the people of ancient India, Egypt, and China. Hundreds of years before the Christian era, cotton textiles were woven in India with matchless skill, and their use spread to the Mediterranean countries.

In Iran (Persia), the history of cotton dates back to the Achaemenid era (5th century BC); however, there are few sources about the planting of cotton in pre-Islamic Iran. The planting of cotton was common in Merv, Ray and Pars of Iran. In Persian poets' poems, especially Ferdowsi's Shahname, there are references to cotton ("panbe" in Persian). Marco Polo (13th century) refers to the major products of Persia, including cotton. John Chardin, a French traveler of the 17th century who visited Safavid Persia, spoke approvingly of the vast cotton farms of Persia.[16]

Cotton (Gossypium herbaceum Linnaeus) may have been domesticated 5000 BCE in eastern Sudan near the Middle Nile Basin region, where cotton cloth was being produced.[17] Around the 4th century BC, the cultivation of cotton and the knowledge of its spinning and weaving in Meroë reached a high level. The export of textiles was one of the sources of wealth for Meroë. Aksumite King Ezana boasted in his inscription that he destroyed large cotton plantations in Meroë during his conquest of the region.[18]

During the Han dynasty (207 BC - 220 AD), cotton was grown by Chinese peoples in the southern Chinese province of Yunnan.[19]

Egyptians grew and spun cotton in the first seven centuries of the Christian era.[20]

Handheld roller cotton gins had been used in India since the 6th century, and was then introduced to other countries from there.[21] Between the 12th and 14th centuries, dual-roller gins appeared in India and China. The Indian version of the dual-roller gin was prevalent throughout the Mediterranean cotton trade by the 16th century. This mechanical device was, in some areas, driven by water power.[22]

The earliest clear illustrations of the spinning wheel come from the Islamic world in the eleventh century.[23] The earliest unambiguous reference to a spinning wheel in India is dated to 1350, suggesting that the spinning wheel was likely introduced from Iran to India during the Delhi Sultanate.[24]

Cotton plants as imagined and drawn by John Mandeville in the 14th century

During the late medieval period, cotton became known as an imported fiber in northern Europe, without any knowledge of how it was derived, other than that it was a plant. Because Herodotus had written in his Histories, Book III, 106, that in India trees grew in the wild producing wool, it was assumed that the plant was a tree, rather than a shrub. This aspect is retained in the name for cotton in several Germanic languages, such as German Baumwolle, which translates as "tree wool" (Baum means "tree"; Wolle means "wool"). Noting its similarities to wool, people in the region could only imagine that cotton must be produced by plant-borne sheep. John Mandeville, writing in 1350, stated as fact that "There grew there [India] a wonderful tree which bore tiny lambs on the endes of its branches. These branches were so pliable that they bent down to allow the lambs to feed when they are hungry." (See Vegetable Lamb of Tartary.)

The Vegetable Lamb of Tartary

Cotton manufacture was introduced to Europe during the Muslim conquest of the Iberian Peninsula and Sicily. The knowledge of cotton weaving was spread to northern Italy in the 12th century, when Sicily was conquered by the Normans, and consequently to the rest of Europe. The spinning wheel, introduced to Europe circa 1350, improved the speed of cotton spinning.[25] By the 15th century, Venice, Antwerp, and Haarlem were important ports for cotton trade, and the sale and transportation of cotton fabrics had become very profitable.[26]

A woman in Dhaka clad in fine Bengali muslin, 18th century.

Under the Mughal Empire, which ruled in the Indian subcontinent from the early 16th century to the early 18th century, Indian cotton production increased, in terms of both raw cotton and cotton textiles. The Mughals introduced agrarian reforms such as a new revenue system that was biased in favour of higher value cash crops such as cotton and indigo, providing state incentives to grow cash crops, in addition to rising market demand.[27]

The largest manufacturing industry in the Mughal Empire was cotton textile manufacturing, which included the production of piece goods, calicos, and muslins, available unbleached and in a variety of colours. The cotton textile industry was responsible for a large part of the empire's international trade.[28] India had a 25% share of the global textile trade in the early 18th century.[29] Indian cotton textiles were the most important manufactured goods in world trade in the 18th century, consumed across the world from the Americas to Japan.[30] The most important center of cotton production was the Bengal Subah province, particularly around its capital city of Dhaka.[31]

The worm gear roller cotton gin, which was invented in India during the early Delhi Sultanate era of the 13th–14th centuries, came into use in the Mughal Empire some time around the 16th century,[32] and is still used in India through to the present day.[21] Another innovation, the incorporation of the crank handle in the cotton gin, first appeared in India some time during the late Delhi Sultanate or the early Mughal Empire.[33] The production of cotton, which may have largely been spun in the villages and then taken to towns in the form of yarn to be woven into cloth textiles, was advanced by the diffusion of the spinning wheel across India shortly before the Mughal era, lowering the costs of yarn and helping to increase demand for cotton. The diffusion of the spinning wheel, and the incorporation of the worm gear and crank handle into the roller cotton gin, led to greatly expanded Indian cotton textile production during the Mughal era.[34]

It was reported that, with an Indian cotton gin, which is half machine and half tool, one man and one woman could clean 28 pounds of cotton per day. With a modified Forbes version, one man and a boy could produce 250 pounds per day. If oxen were used to power 16 of these machines, and a few people's labour was used to feed them, they could produce as much work as 750 people did formerly.[35]

In the early 19th century, a Frenchman named M. Jumel proposed to the great ruler of Egypt, Mohamed Ali Pasha, that he could earn a substantial income by growing an extra-long staple Maho (Gossypium barbadense) cotton, in Lower Egypt, for the French market. Mohamed Ali Pasha accepted the proposition and granted himself the monopoly on the sale and export of cotton in Egypt; and later dictated cotton should be grown in preference to other crops.

Egypt under Muhammad Ali in the early 19th century had the fifth most productive cotton industry in the world, in terms of the number of spindles per capita.[36] The industry was initially driven by machinery that relied on traditional energy sources, such as animal power, water wheels, and windmills, which were also the principal energy sources in Western Europe up until around 1870.[37] It was under Muhammad Ali in the early 19th century that steam engines were introduced to the Egyptian cotton industry.[37]

By the time of the American Civil war annual exports had reached $16 million (120,000 bales), which rose to $56 million by 1864, primarily due to the loss of the Confederate supply on the world market. Exports continued to grow even after the reintroduction of US cotton, produced now by a paid workforce, and Egyptian exports reached 1.2 million bales a year by 1903.

Cotton bales at the port in Bombay, India, 1860's.

The English East India Company (EIC) introduced the British to cheap calico and chintz cloth on the restoration of the monarchy in the 1660s. Initially imported as a novelty side line, from its spice trading posts in Asia, the cheap colourful cloth proved popular and overtook the EIC's spice trade by value in the late 17th century. The EIC embraced the demand, particularly for calico, by expanding its factories in Asia and producing and importing cloth in bulk, creating competition for domestic woollen and linen textile producers. The impacted weavers, spinners, dyers, shepherds and farmers objected and the calico question became one of the major issues of National politics between the 1680s and the 1730s. Parliament began to see a decline in domestic textile sales, and an increase in imported textiles from places like China and India. Seeing the East India Company and their textile importation as a threat to domestic textile businesses, Parliament passed the 1700 Calico Act, blocking the importation of cotton cloth. As there was no punishment for continuing to sell cotton cloth, smuggling of the popular material became commonplace. In 1721, dissatisfied with the results of the first act, Parliament passed a stricter addition, this time prohibiting the sale of most cottons, imported and domestic (exempting only thread Fustian and raw cotton). The exemption of raw cotton from the prohibition initially saw 2 thousand bales of cotton imported annually, to become the basis of a new indigenous industry, initially producing Fustian for the domestic market, though more importantly triggering the development of a series of mechanised spinning and weaving technologies, to process the material. This mechanised production was concentrated in new cotton mills, which slowly expanded till by the beginning of the 1770s seven thousand bales of cotton were imported annually, and pressure was put on Parliament, by the new mill owners, to remove the prohibition on the production and sale of pure cotton cloth, as they could easily compete with anything the EIC could import.

The acts were repealed in 1774, triggering a wave of investment in mill based cotton spinning and production, doubling the demand for raw cotton within a couple of years, and doubling it again every decade, into the 1840s[38]

Indian cotton textiles, particularly those from Bengal, continued to maintain a competitive advantage up until the 19th century. In order to compete with India, Britain invested in labour-saving technical progress, while implementing protectionist policies such as bans and tariffs to restrict Indian imports.[39] At the same time, the East India Company's rule in India contributed to its deindustrialization, opening up a new market for British goods,[39] while the capital amassed from Bengal after its 1757 conquest was used to invest in British industries such as textile manufacturing and greatly increase British wealth.[40][41] British colonization also forced open the large Indian market to British goods, which could be sold in India without tariffs or duties, compared to local Indian producers who were heavily taxed, while raw cotton was imported from India without tariffs to British factories which manufactured textiles from Indian cotton, giving Britain a monopoly over India's large market and cotton resources.[42][39][43] India served as both a significant supplier of raw goods to British manufacturers and a large captive market for British manufactured goods.[44] Britain eventually surpassed India as the world's leading cotton textile manufacturer in the 19th century.[39]

India's cotton-processing sector changed during EIC expansion in India in the late 18th and early 19th centuries. From focusing on supplying the British market to supplying East Asia with raw cotton. As the Artisan produced textiles were no longer competitive with those produced Industrially, and Europe preferring the cheaper slave produced, long staple American, and Egyptian cottons, for its own materials.

The advent of the Industrial Revolution in Britain provided a great boost to cotton manufacture, as textiles emerged as Britain's leading export. In 1738, Lewis Paul and John Wyatt, of Birmingham, England, patented the roller spinning machine, as well as the flyer-and-bobbin system for drawing cotton to a more even thickness using two sets of rollers that traveled at different speeds. Later, the invention of the James Hargreaves' spinning jenny in 1764, Richard Arkwright's spinning frame in 1769 and Samuel Crompton's spinning mule in 1775 enabled British spinners to produce cotton yarn at much higher rates. From the late 18th century on, the British city of Manchester acquired the nickname "Cottonopolis" due to the cotton industry's omnipresence within the city, and Manchester's role as the heart of the global cotton trade.

Production capacity in Britain and the United States was improved by the invention of the modern cotton gin by the American Eli Whitney in 1793. Before the development of cotton gins, the cotton fibers had to be pulled from the seeds tediously by hand. By the late 1700s, a number of crude ginning machines had been developed. However, to produce a bale of cotton required over 600 hours of human labor,[45] making large-scale production uneconomical in the United States, even with the use of humans as slave labor. The gin that Whitney manufactured (the Holmes design) reduced the hours down to just a dozen or so per bale. Although Whitney patented his own design for a cotton gin, he manufactured a prior design from Henry Odgen Holmes, for which Holmes filed a patent in 1796.[45] Improving technology and increasing control of world markets allowed British traders to develop a commercial chain in which raw cotton fibers were (at first) purchased from colonial plantations, processed into cotton cloth in the mills of Lancashire, and then exported on British ships to captive colonial markets in West Africa, India, and China (via Shanghai and Hong Kong).

By the 1840s, India was no longer capable of supplying the vast quantities of cotton fibers needed by mechanized British factories, while shipping bulky, low-price cotton from India to Britain was time-consuming and expensive. This, coupled with the emergence of American cotton as a superior type (due to the longer, stronger fibers of the two domesticated native American species, Gossypium hirsutum and Gossypium barbadense), encouraged British traders to purchase cotton from plantations in the United States and in the Caribbean. By the mid-19th century, "King Cotton" had become the backbone of the southern American economy. In the United States, cultivating and harvesting cotton became the leading occupation of slaves.

During the American Civil War, American cotton exports slumped due to a Union blockade on Southern ports, and also because of a strategic decision by the Confederate government to cut exports, hoping to force Britain to recognize the Confederacy or enter the war. The Lancashire Cotton Famine prompted the main purchasers of cotton, Britain and France, to turn to Egyptian cotton. British and French traders invested heavily in cotton plantations. The Egyptian government of Viceroy Isma'il took out substantial loans from European bankers and stock exchanges. After the American Civil War ended in 1865, British and French traders abandoned Egyptian cotton and returned to cheap American exports, sending Egypt into a deficit spiral that led to the country declaring bankruptcy in 1876, a key factor behind Egypt's occupation by the British Empire in 1882.

During this time, cotton cultivation in the British Empire, especially Australia and India, greatly increased to replace the lost production of the American South. Through tariffs and other restrictions, the British government discouraged the production of cotton cloth in India; rather, the raw fiber was sent to England for processing. The Indian Mahatma Gandhi described the process:

1. English people buy Indian cotton in the field, picked by Indian labor at seven cents a day, through an optional monopoly.
2. This cotton is shipped on British ships, a three-week journey across the Indian Ocean, down the Red Sea, across the Mediterranean, through Gibraltar, across the Bay of Biscay and the Atlantic Ocean to London. One hundred per cent profit on this freight is regarded as small.
3. The cotton is turned into cloth in Lancashire. You pay shilling wages instead of Indian pennies to your workers. The English worker not only has the advantage of better wages, but the steel companies of England get the profit of building the factories and machines. Wages; profits; all these are spent in England.
4. The finished product is sent back to India at European shipping rates, once again on British ships. The captains, officers, sailors of these ships, whose wages must be paid, are English. The only Indians who profit are a few lascars who do the dirty work on the boats for a few cents a day.
5. The cloth is finally sold back to the kings and landlords of India who got the money to buy this expensive cloth out of the poor peasants of India who worked at seven cents a day.[46]

In the United States, growing Southern cotton generated significant wealth and capital for the antebellum South, as well as raw material for Northern textile industries. Before 1865 the cotton was largely produced through the labor of enslaved African Americans. It enriched both the Southern landowners and the new textile industries of the Northeastern United States and northwestern Europe. In 1860 the slogan "Cotton is king" characterized the attitude of Southern leaders toward this monocrop in that Europe would support an independent Confederate States of America in 1861 in order to protect the supply of cotton it needed for its very large textile industry.[47]

Cotton remained a key crop in the Southern economy after slavery ended in 1865. Across the South, sharecropping evolved, in which landless farmers worked land owned by others in return for a share of the profits. Some farmers rented the land and bore the production costs themselves. Until mechanical cotton pickers were developed, cotton farmers needed additional labor to hand-pick cotton. Picking cotton was a source of income for families across the South. Rural and small town school systems had split vacations so children could work in the fields during "cotton-picking."[48]

During the middle 20th century, employment in cotton farming fell, as machines began to replace laborers and the South's rural labor force dwindled during the World Wars. Cotton remains a major export of the United States, with large farms in California, Arizona and the Deep South.[49]

China's Chang'e 4 brought cotton seeds to the Moon's far side. On 15 January 2019, China announced that a cotton seed sprouted, the first "truly otherworldly plant in history". Inside the Von Kármán Crater, the capsule and seeds sit inside the Chang'e 4 lander.[50]

World Cotton Day is celebrated on 7 October. This day was initiated in 2019.[51]

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.[61][62][63] The gene coding for Bt toxin has been inserted into cotton, causing cotton, called Bt cotton, to produce this natural insecticide in its tissues. In many regions, the main pests in commercial cotton are lepidopteran 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.

However, Bt cotton is ineffective against many cotton pests, such as plant bugs, stink bugs, and aphids; depending on circumstances it may still be desirable to use insecticides against these. A 2006 study done by Cornell researchers, the Center for Chinese Agricultural Policy and the Chinese Academy of Science on Bt cotton farming in China found that after seven years these secondary pests that were normally controlled by pesticide had increased, necessitating the use of pesticides at similar levels to non-Bt cotton and causing less profit for farmers because of the extra expense of GM seeds.[64] However, a 2009 study by the Chinese Academy of Sciences, Stanford University and Rutgers University refuted this.[65] They concluded that the GM cotton effectively controlled bollworm. The secondary pests were mostly miridae (plant bugs) whose increase was related to local temperature and rainfall and only continued to increase in half the villages studied. Moreover, the increase in insecticide use for the control of these secondary insects was far smaller than the reduction in total insecticide use due to Bt cotton adoption. A 2012 Chinese study concluded that Bt cotton halved the use of pesticides and doubled the level of ladybirds, lacewings and spiders.[66][67] The International Service for the Acquisition of Agri-biotech Applications (ISAAA) said that, worldwide, GM cotton was planted on an area of 25 million hectares in 2011.[68] This was 69% of the worldwide total area planted in cotton.

GM cotton acreage in India grew at a rapid rate, increasing from 50,000 hectares in 2002 to 10.6 million hectares in 2011. The total cotton area in India was 12.1 million hectares in 2011, so GM cotton was grown on 88% of the cotton area. This made India the country with the largest area of GM cotton in the world.[68] A long-term study on the economic impacts of Bt cotton in India, published in the Journal PNAS in 2012, showed that Bt cotton has increased yields, profits, and living standards of smallholder farmers.[69] The U.S. GM cotton crop was 4.0 million hectares in 2011 the second largest area in the world, the Chinese GM cotton crop was third largest by area with 3.9 million hectares and Pakistan had the fourth largest GM cotton crop area of 2.6 million hectares in 2011.[68] The initial introduction of GM cotton proved to be a success in Australia – the yields were equivalent to the non-transgenic varieties and the crop used much less pesticide to produce (85% reduction).[70] The subsequent introduction of a second variety of GM cotton led to increases in GM cotton production until 95% of the Australian cotton crop was GM in 2009[71] making Australia the country with the fifth largest GM cotton crop in the world.[68] Other GM cotton growing countries in 2011 were Argentina, Myanmar, Burkina Faso, Brazil, Mexico, Colombia, South Africa and Costa Rica.[68]

Cotton has been genetically modified for resistance to glyphosate a broad-spectrum herbicide discovered by Monsanto which also sells some of the Bt cotton seeds to farmers. There are also a number of other cotton seed companies selling GM cotton around the world. About 62% of the GM cotton grown from 1996 to 2011 was insect resistant, 24% stacked product and 14% herbicide resistant.[68]

Cotton has gossypol, a toxin that makes it inedible. However, scientists have silenced the gene that produces the toxin, making it a potential food crop.[72] On 17 October 2018, the USDA deregulated GE low-gossypol cotton.[73][74]

Organic cotton is generally understood as cotton from plants not genetically modified and that is certified to be grown without the use of any synthetic agricultural chemicals, such as fertilizers or pesticides.[75] Its production also promotes and enhances biodiversity and biological cycles.[76] In the United States, organic 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.[77] 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.[78] Organic cotton products are now available for purchase at limited locations. These are popular for baby clothes and diapers; natural cotton products are known to be both sustainable and hypoallergenic.

Significant global pests of cotton include various species of bollworm, such as Pectinophora gossypiella. Sucking pests include cotton stainers, the chili thrips, Scirtothrips dorsalis; the cotton seed bug, Oxycarenus hyalinipennis. Defoliatores include the fall armyworm, Spodoptera frugiperda.

Historically, in North America, one of the most economically destructive pests in cotton production has been the boll weevil. Due to the US Department of Agriculture's highly successful Boll Weevil Eradication Program (BWEP), this pest has been eliminated from cotton in most of the United States. This program, along with the introduction of genetically engineered Bt cotton, has improved the management of a number of pests such as cotton bollworm and pink bollworm). Sucking pests include the cotton stainer, Dysdercus suturellus and the tarnish plant bug, Lygus lineolaris. A significant cotton disease is Xanthomonas citri subsp. malvacearum.

Top 10 Cotton Producing Countries (in 1000 metric tonnes)
Rank	Country	2019
1	India	5,770
2	United States	3,999
3	China	3,500
4	Brazil	2,787
5	Pakistan	1,655
6	Turkey	806
7	Uzbekistan	713
8	Australia	479
9	Turkmenistan	198
10	Burkina Faso	185
Source: UN Food & Agriculture Organization[97]

The five leading exporters of cotton in 2019 are (1) India, (2) the United States, (3) China, (4) Brazil, and (5) Pakistan.

In India, the states of Maharashtra (26.63%), Gujarat (17.96%) and Andhra Pradesh (13.75%) and also Madhya Pradesh are the leading cotton producing states,[98] these states have a predominantly tropical wet and dry climate.

In the United States, the state of Texas led in total production as of 2004,[99] while the state of California had the highest yield per acre.[100]

Cotton is an enormously important commodity throughout the world. However, many farmers in developing countries receive a low price for their produce, or find it difficult to compete with developed countries.

This has led to an international dispute (see Brazil–United States cotton dispute):

On 27 September 2002, Brazil requested consultations with the US regarding prohibited and actionable subsidies provided to US producers, users and/or exporters of upland cotton, as well as legislation, regulations, statutory instruments and amendments thereto providing such subsidies (including export credits), grants, and any other assistance to the US producers, users and exporters of upland cotton.[101]

On 8 September 2004, the Panel Report recommended that the United States "withdraw" export credit guarantees and payments to domestic users and exporters, and "take appropriate steps to remove the adverse effects or withdraw" the mandatory price-contingent subsidy measures.[102]

While Brazil was fighting the US through the WTO's Dispute Settlement Mechanism against a heavily subsidized cotton industry, a group of four least-developed African countries – Benin, Burkina Faso, Chad, and Mali – also known as "Cotton-4" have been the leading protagonist for the reduction of US cotton subsidies through negotiations. The four introduced a "Sectoral Initiative in Favour of Cotton", presented by Burkina Faso's President Blaise Compaoré during the Trade Negotiations Committee on 10 June 2003.[103]

In addition to concerns over subsidies, the cotton industries of some countries are criticized for employing child labor and damaging workers' health by exposure to pesticides used in production. The Environmental Justice Foundation has campaigned against the prevalent use of forced child and adult labor in cotton production in Uzbekistan, the world's third largest cotton exporter.[104] The international production and trade situation has led to "fair trade" cotton clothing and footwear, joining a rapidly growing market for organic clothing, fair fashion or "ethical fashion". The fair trade system was initiated in 2005 with producers from Cameroon, Mali and Senegal.[105]

A display from a British cotton manufacturer of items used in a cotton mill during the Industrial Revolution.

A bale of cotton on display at the Louisiana State Cotton Museum in Lake Providence in East Carroll Parish in northeastern Louisiana

Cotton is bought and sold by investors and price speculators as a tradable commodity on 2 different commodity exchanges in the United States of America.

• Cotton No. 2 futures contracts are traded on the New York Board of Trade (NYBOT) under the ticker symbol CT. They are delivered every year in March, May, July, October, and December.[106]
• Cotton futures contracts are traded on the New York Mercantile Exchange (NYMEX) under the ticker symbol TT. They are delivered every year in March, May, July, October, and December.[107]

• Favorable travel temperature range: below 25 °C (77 °F)
• Optimum travel temperature: 21 °C (70 °F)
• Glow temperature: 205 °C (401 °F)
• Fire point: 210 °C (410 °F)
• Autoignition temperature: 360 °C (680 °F) - 425 °C (797 °F)[108]
• Autoignition temperature (for oily cotton): 120 °C (248 °F)

A temperature range of 25 to 35 °C (77 to 95 °F) is the optimal range for mold development. At temperatures below 0 °C (32 °F), rotting of wet cotton stops. Damaged cotton is sometimes stored at these temperatures to prevent further deterioration.[109]

Egypt has a unique climatic temperature that the soil and the temperature provide an exceptional environment for cotton to grow rapidly.

Cotton has a more complex structure among the other crops. A matured cotton fiber is a single, elongated complete dried multilayer cell that develops in the surface layer of cottonseed. It has the following parts.[111]

1. Cuticle, is the outer most layer. It is a waxy layer that contains pectins and proteinaceos materials.[112]
2. Primary wall, is the original thin cell wall. Primary wall is mainly cellulose, it is made up of a network of fine fibrils (small strands of cellulose).[112]
3. Winding layer, is the first layer of secondary thickening it is also called the S1 layer . It is different in structure from both the primary wall and the remainder of the secondary wall. It consists of fibrils aligned at 40 to 70-degree angles to the fiber axis in an open netting type of pattern.[112]
4. Secondary wall, is consists of concentric layers of cellulose it is also called the S2 layer, that constitute the main portion of the cotton fiber. After the fiber has attained its maximum diameter, new layers of cellulose are added to form the secondary wall. The fibrils are deposited at 70 to 80-degree angles to the fiber axis, reversing angle at points along the length of the fiber.[112]
5. Lumen, is the hollow canal that runs the length of the fiber. It is filled with living protoplast during the growth period. After the fiber matures and the boll opens, the protoplast dries up, and the lumen naturally collapses, leaving a central void, or pore space, in each fiber. It separates the secondary wall from the lumen and appears to be more resistant to certain reagents than the secondary wall layers.The lumen wall also called the S3 layer.[112][113][111]