Cotton is the one of the world’s leading cash crops. It can be economically produced and making cotton products is also relatively inexpensive. Cotton fabrics are extremely durable and resistant to abrasion. Cotton accepts many dyes, is usually washable, and can be ironed at relatively high temperatures. It is comfortable to wear because it absorbs and releases moisture quickly. When warmth is desired, it can be napped, a process giving the fabric a downy surface.

Climate and Soil
Cotton grows in sub-tropical climate. It needs an average minimum temperature of 60 degree Fahrenheit for germination, 70 – 80 degrees Fahrenheit for vegetative growth and 80 – 90 degree Fahrenheit with cool nights during fruiting period. Generally, an annual rainfall of minimum 50 cm is required unless it is grown on irrigated soil. The weather should be clear at harvesting time because rain will discolor the lint and reduce its quality.
It grows well in a soil which has an excellent holding capacity, aeration and good drainage. It cannot tolerate excessive moisture and water logging. Cotton cultivation favors alluvial soil, black soil, and red sand loam.

Land Preparation

The soil must be ploughed, loosened and harrowed to make suitable for cultivation. The land should be deep ploughed once in 3 years and twice shallow ploughed each year. Deep ploughing controls deep-rooted weeds and destroys the pest larvae or cocoons. Crop residue is one of the major sources of nutrients. The crop residue from previous cotton-legume intercrop should be incorporated into the soil at the time of ploughing. Green manuring also maintains soil fertility, but this can be adopted only under irrigated conditions or under cotton-legume crop rotation. The trees also attract birds that control the pests.

Seed Treatment

The seeds need to be treated with a mixture of Beejamrut (200gm/kg seed) and Trichoderma viridi (8 gm/kg of seed) and then dried in the shade. Again the seeds need to be treated with Azotobacter and Phosphorous Solubilizing Bio-fertilizers (5gm each per kg of seed) and the treated seeds would need to be dried in the shade. Finally, the treated seeds should be sown within 6-8 hours of treatment.


Sowing

Sowing is done by using tractor or bullock drawn seed drill or by dibbling. As per the biodynamic calendar, sowing should be done around full moon days. Seeds are sown in north-south direction because this orientation ensures better sun harvesting and prevents carbon dioxide (CO2) loss emitted by the crop during night. The crop can re-absorb it, in day resulting into better growth. For better sun-harvesting, sow only 5-7 kg/hectare and spacing of 50-90 cm between rows should be maintained.


Fertilizers

The fertilizers are applicable depending upon the nutrients in the soil.For dry lands, 20 kg of nitrogen, 18 kg of phosphorus and 78 kg potash is economical. Nitrogen is applied in split doses, half dose at the time of sowing and other half as top dressing during thinning or just before flowering. For irrigated cotton, this dose can be doubled


Irrigation

Generally, the cotton crop needs 6-8 irrigation and about 600-800 mm of water during its entire growth period. The water requirement is lower during the first 60-70 days, and highest during flowering and boll formation stage. Inadequate irrigation schedule during these stages leads to a heavy shedding of flower buds and bolls.
In sandy loam soil, 3-5 irrigations are given. In red sandy loam soil with low water retention capacity, 4-10 light irrigations may be needed. In black cotton soil, protective irrigation is provided every 20 days, (if rains fail), especially during boll development stage.
Cotton is commonly flood irrigated but irrigation by furrow or alternate furrow method is more effective and saves water. In sloppy areas, channels parallel to the contour lines, across the slope prevent erosion. Water the alternate rows to reduce weeds and root rot diseases. Drip irrigation is also very effective. Mulching of soil surface with intercrop biomass after 60 days reduces irrigation requirements by 40-60%. Mulching is very effective under purely rain fed conditions


Disease and Pests

By spraying Malathion 0.08%, cotton aphids and cotton jassids are controlled. By dusting crop with 10% carbonyl, cotton leaf roller, spotted boll worm, pink boll worm are controlled whereas red cotton bug and dusky cotton bug are controlled by dusting 5% benzene hexa-chloride (BHC).

Disease Management in Cotton


Harvesting

Harvesting should be done at frequent intervals of less than 7 days. The weather should be clear at harvesting because rain will discolor the lint and reduce its quality. It should be done during morning hours when there is moisture so that dry leaves and bracts do not stick to the cotton and lower the market value. Pick cotton from well burst bolls only. Remove only the cotton from the bolls and leave the bracts on the plants. After cotton is picked, sort out good puffy ones and keep separately. Keep stained, discolored and insect attacked cotton separately.