Cotton crops are soft, fluffy stable fiber that is used extensively in the textile industry. The fiber is made of almost pure cellulose and contains few traces of waxes, fats and water. Cotton is one of the most important cash crops in India and it plays a crucial role in the industrial and agricultural economy. Direct cotton in India provides direct livelihood to 6 million farmers and indirectly employs about 40-50 million people in its allied processes such as trade and processing.There are four cultivated species of cotton viz. Gossypium arboreum, G.herbaceum, G.hirsutum and G.barbadense. Perhaps, India is the only country in the world where all the four cultivated species are grown on a commercial scale. Cotton is grown in tropical & subtropical conditions. a minimum temperature of 15oC is required for better germination at field conditions. The optimum temperature for vegetative growth is 21-27oC & it can tolerate temperature to the extent of 43oC but temperature below 21oC is detrimental to the crop. Warm days of Cool nights with large diurnal variations during the period of fruiting are conducive to good boll & fibre development. Cotton is grown on a variety of soils ranging from well drained deep alluvial soils in the north to black clayey soils of varying depth in the central region and in black and mixed black and red soils in the south zone. Cotton is semi-tolerant to salinity and sensitive to water logging and thus prefers well drained soils.mm The sowing season of cotton varies considerably from tract to tract and is generally early (April-May) in northern India and is delayed as its proceeds down south (monsoon based in southern zone). Cotton is a Kharif crop in the major parts of the country viz. Punjab, Haryana, Rajasthan, Uttar Pradesh, Madhya Pradesh, Gujarat, Maharashtra and parts of Andhra Pradesh & Karnataka.
