Cotton is cultivated in a warm humid climate. Black soil is considered best as it can hold moisture well. The cotton seeds are sown in fields around 3-4 feet apart in parallel rows. Irrigation is compulsory for plants growth. The plant grows to its full form within 80-1000 days and blossoms appear on plants. When open, it is creamy white in color which turns into pink within a day. The pods appear within 50 -80 days and after attaining maturity, it bursts open and exposes the white fleece. Picking of cotton is done manually or by use of machine. Hand picking is very common in labour intensive countries and machines are employed in all western countries. The quality of cotton largely depends on picking operation. If the fleece alone is picked up carefully avoiding the burs and dried leaves, cotton will have good quality and is priced high. Of more impurities are present in cotton, it needs more cleaning, thus it is priced low.
After cotton is picked, it is taken to a ginning mill where the fibre is separated from its seed. Generally around 4000 fibres
emerge from a single cotton seed. Fine variety cotton can yield as much as 20000 fibres from each seed. When cotton arrives at ginning mill, it contains seeds burs, leaf fragments, dirt etc which should be removed before it is sent for spinning. Cotton gin, a machine invented by Whitney in 1974 is capable of separating cotton fleece from its impurities. It has rows of revolving saw toothed bands that pull the fibre away from the seeds and the impurities. Cotton seeds are important by-products from which oil is extracted. Cotton free from major impurities are baled and sent to spinning factories. The spinning of cotton fibre is explained under the spinning chapter.
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