Top 2 Types of Fibers | Plant Breeding

The following points highlight the top types of fibers. The types are: 1. Cotton 2. Jute. 

Type # 1. Cotton:

Cotton is the world’s greatest industrial crop, the chief fibre yielding plant. All the cultivated cottons fall under 4 species; 2 belonging to old world, Gossypium arboreum and G. herbaceum which are diploid in nature; another 2 belonging to new world, Gossypium hirsutum and G. barbadense which are tetraploid in nature.

Areas of Cultivation:

In India cotton is mainly cultivated in the states of South Western India – Gujarat, Maharashtra, Karnataka, Tamil Nadu, Kerala, Madhya Pradesh, Punjab, Rajasthan, Uttar Pradesh, Haryana.

Climate:

Cotton grows well in sub-tropical areas with following climatic condi­tions:

Soil:

Cotton grows best in well drained loamy soils. Indo-Gangetic alluvial soil, black soil of Central and Southern India and also red laterite soil are good for cotton production.

Rotation:

Cotton is commonly rotated with wheat, legume, jowar, bajra, sesamum, etc.

Preparation of Land:

Before sowing the land is given one or two ploughings in South and some parts of North India, whereas in Central and Western India the land is harrowed three or four times, and ploughing is done once.

Sowing:

Seeds are generally sown by broadcasting or drilling method at the rate of 15-25 kg/ha for new world cotton and 10-18 kg/ha for old world cotton during April to July. Mechanical sowing is done keeping the space 45-60 cm in between rows and 30-45 cm within the rows. Before sowing, cotton seeds are treated with different types of chemi­cal reagents or mud or cow-dung due to the fuzziness of seeds.

Manuring:

Generally cotton is not manured sufficiently. Green manure, i.e., legu­minous crop may be grown before cotton. Fertiliser dose depends on the variety and location of cotton crop grown. Nitrogen @ 40-100 kg/ha and phosphate @ 20-80 kg/ha are applied for irrigated cotton and half of this dose is required for rainfed crop.

After Care:

Weeds are removed with the help of hand hoes in some places. Cotton is mainly un-irrigated crop, watering is required at the time of flowering and fruiting stage. For maturation of bolls, sufficient soil moisture is required.

Disease and Control:

Common diseases of cotton and their control are as follows:

Pest and Control:

Common cotton pests and their control measures are as follows:

Harvesting:

Harvesting is done during October to March. It is harvested in 3 or 4 pickings after the maturity of bolls. Seed cotton is removed from the bolls in the field; in closed-boll cottons, partially open bolls are collected from the plants in the field.

Yield:

The average yield of seed-cotton is 400-600 kg/ha. The lint yield is 150-200 kg/ha.

Crop Improvement through Plant Breeding:

The All India Coordinated Cotton Improvement Project started in 1967 and now there are 30 centres in various agro-climatic zones.

(a) Hybrid Variety Production:

‘Hybrid 4’ is the breakthrough in cotton pro­duction, which is the first commercial hybrid in India. ‘Varalakshmi’ is an­other hybrid variety developed next. ‘Sujata’ and ‘Suvin’ are the two high spinning cotton varieties.

(b) Improvement through Selection:

Examples of few cotton varieties after pure line selection are: Co-2, Co-7, A-10, A-231R, C520, etc. Mass selection has yielded the varieties like – Dodahatti local, Dharwar American, Combodian cotton, etc.

(c) Mutation Breeding:

Mutagenic treatment in existing varieties developed some new useful characters better than the parental variety. MCU-7 is the mutant variety obtained from L114 EE variety.

(d) Cytoplasmic Male Sterile Line Development:

Introduction of cytoplasmic male sterility to cultivars from wild species is another potential use of Gossypium cytoplasm. The nucleus of G. hirsutum has been incorporated into a number of cytoplasm’s of wild species. The male fertility restorer genes have been identified in several cases.

(e) Improvement through Amphidiploid Production:

For improvement, wild cotton species can be utilized. The F1 plants are treated with colchicine and the amphidiploids produced, are crossed with cultivated tetraploid species. For example, (G. thurberi x G. arboreum) x G. hirsutum and back-crossed to G. hirsutum, developed lines with superior lint quality but otherwise poor quality would be there.

Some important improved varieties:

Research Station:

Central Cotton Research Institute, Nagpur.

Type # 2. Jute:

Next to cotton, jute forms the most important Indian fibre crop used more extensively for various purposes. Two species, Corchorus capsularis and C. olitorius are cultivated.

Areas of Cultivation:

In India, jute is grown mostly in the states of North-East India – West Bengal, Bihar, U.P., Orissa, Assam, Tripura and Meghalaya. The crop is culti­vated annually on about 8 lakh hectares in India.

Climate:

Jute grows well in warm and humid climate.

Soil:

Jute grows well on the soil which is neither very heavy clay nor very sandy. Loamy alluvial soil with deposits of fertile silts is best for jute cultivation. The optimum soil pH is about 6.4.

Preparation of Land:

As jute seeds are very small, it requires a clean and clod-free seed bed. Therefore, the land is ploughed and cross ploughed for at least 5-6 times. After each operation, the land is laddered for breaking up the clods.

Manuring:

Additional manuring is generally not required in soil receiving fresh silt. In other soils, 40-80 q/ha of well rotten cattle manure or compost and 450 kg/ha of weed ash are used during preparation of land.

Sowing:

After treatment with organo-mercurial compounds or Bavistin 50%, the seeds are generally sown by broadcasting at the rate of 5.-8 kg/ha. Nowadays, line sowing with seed drills has been greatly adopted. In this practice, seeds are sown in rows with a spacing of 20-22 cm. between the rows and 5-7 cm within the row.

Sowing Time Varies According to Species:

After-Care:

When the seedlings attain a height of 7-20 cm, the crop is then lightly hoed with ‘bida’ or ‘achra’; subsequently two or three hand weeding are given and the crop is gradually thinned to a spacing of 9-10 cm between plants in broadcasted fields.

Disease and Control:

Common diseases of jute and their control measures are as follows:

Pest and Control:

Common jute pests and their control measures are as follows:

Crop Rotation:

Jute is rotated with paddy and pulses. On lowlands, jute follow paddy (aman) constitutes the normal rotation. On highlands, the crop is grown in rotation with pulses (gram, pea, etc.), potato, wheat, barley, oat, mustard.

Harvesting:

The crop is to be harvested 120-135 days after planting when pods begin to appear. Depending on the variety grown and the time of sowing, the harvesting period varies from June to October.

At the time of harvesting, plants are cut near the ground level or in case of flooded land, plants are uprooted. The harvested plants are usually left on dry land for 3-4 days for the shedding and the drying up of leaves, then tied in bundles and kept covered with green leaves, weeds or earth for 3-4 days.

Extraction of Fibre (Processing of Jute):

(a) Retting or Steeping:

Bundles are retted or steeped in gently flowing, fairly deep, clean, soft water for 10-15 days in July-September to rot out the softer gummy tissues. Sometimes retting may take 25 days or more specially when the temperature of water is low.

In this process complete submergence of stalks is essential to ensure proper retting of the root end. The bundles with their root ends are generally kept in water for 2-4 days before entire bundles are fully submerged.

(b) Stripping:

After retting is complete, the stalks are stripped by “beat-break- jerk” process. In this operation 8-10 stalks are taken at a time, their root ends beaten with a wooden or bamboo mallet until the fibres are loosened. Loos­ened fibres are then wrapped around the fingers and the stalks or stems are jerked forward and backward over the surface of water till the fibre is com­pletely separated.

The separated fibre is then rinsed, washed, cleaned, wrung and piled on the ground. Finally, strands are opened out and dried in the sun for 2-4 days and tied into bales, ready for the market. The fibre content of the plant varies from 4.5-7.5%.

Yield:

The yield varies according to species and variety:

Capsaicin’s: 9.0-13.5 quintals of dry fibres/hectare

olitorius: 13.5-18.8 quintals of dry fibres/hectare

Recently recommended improved varieties have yield potential of 40 q./ha.

Improvement of the Crop through Plant Breeding:

Improvement of jute is being done through following breeding practices:

(a) Selection:

JRC-321, a variety suitable for lowland cultivation, is the product of selection from local variety Hewti.

(b) Hybridization:

JRO-3690, a high yielding variety, is an example of crossing of two low yielding mutants of C. olitorius.

(c) Mutation Breeding:

Improved varieties JRO-514, JRO-412 are the result of mutation breeding of C. olitorius.

Improved Varieties:

Research Station:

Jute Agricultural Research Institute (JARI), Nilganj, Barrackpore, West Bengal, established in 1953 has two sections:

(i) Research Station in Assam,

(ii) Multiplication farm at Panagarh.

Jute Technological Research Laboratories (1938) was transferred to ICAR in 1965 which work on:

(i) Technological Research on Jute,

(ii) Evaluation of fibre quality of new strains.