Cotton

Land Requirements Land to be used for production of cotton seed must be free of volunteer plants of cotton. The soil should be deep, well drained, retentive of moisture and fertile. There should be no hard pan in the sub-surface layer and also it should be free from the hard layer of carbonates that interferes in the proper development of plants, and therefore the seed.  
Isolation Requirements Cotton is mainly a self-pollinated crop, but natural corss-pollination to the extent of 10 to 50 per cent in g.hirsutum, 1 to 2 per cent in g.arboreum and 5 to 10 per cent in G.barbadense has been recorded in various countries. The actual isolation requirement varies according to the extent of natural cross-pollination. For cotton seed production, only one vareity at a farm is a highly desired practice. In India, a minimum isolation distance of fifty metres for foundation seed class and thirty metres for certified seed class production, from fields of other varieties, of the same species, fields of the same variety not conforming to varietal purity requirements for certification, and five metres from varieties of different spp.(different poidy levels) is required.

 

Cultural Practices

Time of Sowing For best results, the cotton should be sown about one week or more earlier than the usual date of the onset of monsoons.
  


Preparation of Land The land should be ploughed deep and harrowed two to three times, followed by levelling to make it well pulverised and levelled.


Source of Seed Obtain breeder's/foundation seeds from source approved by a seed certification agency. The seed is usually treated with the appropriate recommended chemicals. If not, it should be treated with mercurials.


 

Method of Sowing and spacing The usual seed rate is 15-25 kg/ha for American cotton and 12-16 kg/ha for desi cotton varieties. Spacing of 75-90 cm between rows and 30-45 cm between the plants is recommended. Apply basal dose of fertilisers along with 25 kg disulphoton, 5 per cent per hectare, or 20 kg phorate, 10 per cent per hectare, to the plot uniformly, at the base of each ridge. the sowing should be done by dibbling two to three seeds per hill. Irrigate immediately after sowing and give second irrigation four days after seeding. In case the germination is unsatisfactory gap tilling may be done by seedlings simulataneously raised in polythene bags. Gap tilling at a later stage is best avoided. the thinning may be done after 20 to 23 days to regulate one seedling per hill.


Fertilisation The seed crop should be raised by liberal application of the various nutrients. the nutrient supply should be made according to the yield potential ofvarieties in different agroclimatic regions. In general, apply 15-25 cart loads of farm yard manure per hectare before opening of ridges. apply 50 kg nitrogen 50 kg phosphorus and 50 kg potash per hectare as a basal dose. Top-dress twice at the rate of 25 kg nitrogen per hectare once after sixty days and again at ninety days from planting.
The crop at no stage should be allowed to suffer due to nutrient deficiency. Foliar sprays at the rate of 20 grams of urea or 15 grams of DAP per litre of spray fluid may be given with advantage during the boll development period, at an interval of ten days.


Spacing  


Irrigation Depending on soil type and climate conditions, irrigate the crop once in 15 to 20 days. Heavy irrigation during flowering period should be avoided. Give light irrigation after each picking. The system of furrow irrigation should be adopted.


Interculture and weed control Intercultivate the field four to five times during the crop period so as to keep the plot clean. Hand weeding may be done when required. Herbicides such as, TOKE-25, MSMA and cotoran can also be used for weed control..


Insect and Disease Control Adopt recommended IPM methods


Roguing Roguing of seed crop for off-types and diseased plants, should begin at seedling stage. the subsequent roguing for off-types and severely diseased plants should be done at square initiation stage and flowering stage.


Picking

The time of picking is an important aspect for maintaining seed quality. the picking should commence when the cotton is fully mature, i.e., when the bolls begin to open. Several pickings may be necesssary since bolls ripen over two to three months. the early pickings give a slightly better germination, but planting seed isbest gathered at the peak of the harvest. The cotton picked from late-formed bolls (last pickings) should not be kept for seeds.
Precautions to be taken in picking:
1.Start picking when bolls are fully mature.
2. Picking should not be done while the bolls are wet from dew or rain.
3. Bolls spoiled due to rains, or damaged by insects, orotherwise damaged, should be picked separately and discarded for seed purposes. Such bolls can be picked 10 to 15 days ahead of the first picking. The damaged bolls should not be picked during normal pickings for seed purposes.
4. The cotton should be clean, with a minimum amount of such material as leaves and plant barks. This reduces the possibility of mechanical damage from excessive machining of the fibre during ginning.
5. Cotton moist in any way should not be picked or stored. At a moisture content of twelve per cent, or more,heating may occur and damage the seed and fibre. Further, damp cottonrequires more processing in the gin and exposes the seed to mechanical damage.
6. the picked cotton, when it is completely dry,should be stored in a dry place and should be covered if not ginned immediately.

 

 

Ginning Ginning has a big role in cotton seed quality. Ginning of cotton seed shouldbe done on one variety gins, or gins approved by the certification agency. the ginning machinery must be thoroughly cleaned before ginning the seed crop. In ginning, the cotton should be subjected to a minimum amount of machining to minimise the mechanical damage.
Seed Yield The average seed yield varies from 3 to 6 qtl per hectare.