Cotton, Industry Sector TEXTILE

COTTON

HISTORY

3,000BC No one knows how old cotton is, but pieces of cotton cloth found in Mexican caves proved to be at least 7,000 years old.  In the Indus River Valley in Pakistan cotton was being grown, spun and woven in 3,000BC.

1500s Cotton was grown by American Indians in the early 1500's and the Spanish raised a cotton crop in Florida in 1556.

1607 Seed was planted by colonists along the James River in Virginia. The colonists were able to produce much cotton but were held back by lack of mechanical know-how.

1790 An English mill worker, Samuel Slater, migrated to America and used his knowledge to build the first American cotton mill.

1793 Eli Whitney patented a machine called the cotton gin to separate the fibres from the seed, a job that had previously been done by hand. Volume per worker increased from 1lb to 50lbs per worker. Harvesting the cotton was another limitation on productivity. Working by hand a picker could pick 450lbs of seed and cotton boll per day.

1850-1871 A picking device was first patented in 1850 and a stripper in 1871. 

Gradually better machinery was developed and by the 1930's the Rust Brothers of Mississipi were using a one row cotton picker to pick 8,000 lbs per day. Todays monster 6 row pickers can cover 100 acres in a day and  pick 100,000 lbs per day.

THE PLANT

The cotton plant is called Gossypium,a member of the Mallow family. There are about 39 different species but only 4 have been domesticated of which the Mexican plant Gossypium hirsutum has become the predominant commercial success. The flower bud blooms and develops into an oval fruit called a boll that splits open at maturity to reveal a mass of long white hairs called lint which cover the numerous brown or black seeds.

CULTIVATION

Successful cultivation requires a long growing season with plenty of sunshine and water, such areas being found in tropical and warm subtropical locations. After harvesting the previous years crop the old plants are reduced to stubble. Seed is planted in spring either following ploughing or, in some cases, directly into the ground under the old stubble. 

Cultivators and herbicides are used to control weed growth. Rows of plants used to be 30 - 40 inches apart but in recent years new harvesting techniques have allowed this to reduce to 15 inches apart. The underside of each leaf contains a small cup-like structure holding nectar. This makes the plant attractive to a variety of insect pests chiefly the boll weevil, a pink larva of a small moth, which burrows into the boll and can destroy the crop. The use of early maturing plans strains together with insecticides controls the problem.

The plant can also suffer from wilt caused by a fungus which enters the root from the soil then manufactures a poison. There is no treatment for this but good land management and the use of genetically modified plants has contained the problem. By Autumn the crop is ready for harvesting.

HARVESTING

Harvesting depends on the bolls opening, achieved by early frosts or chemicals. Prior to that the plants are sprayed with defoliants to remove the leaves. This usually happens when bolls are 60-80% open and about two weeks before picking. The removal of leaves makes the final ripening more even, eliminates material that could stain the fibres and makes easier picking with less waste collected by the harvester.

YIELDS

Are expressed in bales of raw cotton per hectare (1 bale =500lbs or 227Kgs) and like all crops will vary due to soil, climate, irrigation and crop management. Without irrigation yields of 3-5 bales per hectare can be expected but this can double with irrigation. Modern technology equips harvesters with satellite navigation so that field/yield maps can be produced to indicate trouble spots and help crop planning.

PROCESSING

The bolls together with sticks, dirt and leaves arrive at the mill and are sucked out of the lorries by long pipes. After removing the debris the cotton moves to the gin stand where the lint is separated from the seeds. The The lint is packed into 500lb bales and is ready for spinning.

The cottonseed, once a waste problem, is now a valuable by-product, broken down by special mills in which the oil is extracted. The seed husks become animal feed, the residual lint becomes padding for furniture and cotton wool swabs, and the left over sediment provides fatty acids for industrial products.

PRODUCTION STATISTICS

Before World War II textile cotton accounted for 80% of material handled by textile mills, but growth of synthetic fibres has reduced this to about 35% today. In 2002 world production of cotton stood at 21m tonnes.  Leading producers are now the United States, China, India Pakistan, Mexico, Egypt, Brazil and Turkey.

Crazy facts Corner

• Cotton growers may fear and hate the Boll Weevil but in Enterprise Alabama  the dreaded bug wiped out the cotton crop and farmers hit back by switching to growing peanuts, a much easier crop. This turning point in their history is marked by the only known monument to the Weevil, a statue of a lady holding one aloft was erected in December 1919.

Links

http://www.cottonsjourney.com
http://www.museums.org.za/bio/plants/malvaceae/gossypium.htm
http://uk.encarta.msn.com/encyslopedia_761562256/Cotton.html
http://www.dpi.qld.au/fieldcrops/8100.html
http://www.al.com/wacky/wacky4.html
http://www.al.com/alabamiana/?wacky4.html

Researched by DynamicDave