Cotton means, “thread”. Cotton is an in determinant plant. There are four cultivated species of cotton.
· Gossipium arborium
· Gossipium herbacium
· Gossipium hirsutum
· Gossipium barbaden
The first two species are called Old-world cotton. It is grown in India, Pakistan. Lint is used in textile and stuffing. The last two species Gossipium hirsutum (American Cotton) and Gossipium barbaden (Egyptian Cotton) are grown in Pakistan and known as “Narma”. Main stem of cotton is called Cotton stick. 40 kg of cotton gives 26-27 Kg of Banola seed and 13-14 Kg of lint. Cotton is important cash crop of Pakistan. 60% of export earning is through cotton 85% domestic oil (vegetative oil) is coming from cotton. It provides raw material to 503 mills in Pakistan and 1135 ginning factories. Yield per hectare is more in Punjab than Sindh.
PLANTING REQUIREMENT OF COTTON:
It is warm season crop. The optimum temperature for germination is between 30-35 °C. At the time of flowering temperature is 34-36 °C.
VEGETATIVE GROWTH PATTERN:
Emergence of leaves from nodes takes place. Healthy root system is present for acquiring soil nutrient. Acropetal (Roots) and Basipetal (Leaves) transport system is present. Main stem is called “monopodial” and branches are called “synpodial”. Root growth is 0.5-2.0 inches each day. Cotyledon unfolds at that time root can grow up to 10 cm. At early vegetative stage root is twice than plant height. At the time of boll setting due to demand of carbohydrate root growth become slow. Root activity become slow gradually when plant mature.
Cotton requires moderately to high irrigation. Cotton can not survive in stagnant water.
SOIL REQUIREMENT AND SOIL PH:
Clay loamy soil is best for cotton. Optimum soil pH for cotton is 5.8-6.5 (slightly acidic). Cotton can also be grown in alkaline soil (pH ranges from 8 and above). The soil should be high in organic matter.
The main varieties grown in Sindh are
Some Punjab varieties grown in Sindh are
SEED VARIETY AND GERMINATION RATE:
Seed variety should be 100% pure and germination rate is 75%. 1 lock of boll contains 6-8 seeds.
1 Kg of sulphuric acid = 10 Kg of cottonseeds.
At the time of germination soil temperature should be less than 30 ° C. Above 60° C temperatures destroy seedling emergence.
Sowing starts at 15th April. Row to row spacing 2.5-3.0 ft. Plant to plant spacing 9 inches approximately.
8-10 Kg seeds per Acre.
Cottonseed is sown by
· Furrow method
· Ridges method
In flat method 25,000-30,000 plants per acre.
· Boll rots.
· Seedling disease.
· Verticillium wilt.
· Ascochyta blight.