The following points highlight the three important fibre yielding plants of India. The fibre plants are: 1. Jute 2. Cotton 3. Sisal Hemp.
Contents
Fibre Plant # 1. Jute (Corchorus Capsularis Linn):
Jute plants are undershrub’s up to 75 cm. high or taller. Leaves are simple, ovate to elliptic, stipulate, serrate, acute or shortly acuminate, rounded at base and often tailed on both sides, pubescent or almost glabrous; lamina up to 7.5 cm. long, 3.5 cm. broad; stipules filiform or subulate. Cymes axillary, 1-few-flowered, bracteate.
Flowers are bisexual, short pedicilled, yellow; buds obovoid. Sepals 4-5, free, oblong-lanceolate 3-4 mm. long. Petals 4-5, free, spathulate, with a short claw, ciliate, 5 mm. long. Stamens twice as many as petals or numerous; anthers 2-celled, dehiscing laterally and longitudinally.
Ovary sessile or on a short gynophore, 2-6 celled with many ovules in each; style thick, stigma cup-shaped, fimbriate. Fruit a loculicidal capsule, many seeded; seeds smooth, brown or black, trigonous or not, about 2 mm. long.
Capsule globose, 1 cm. in diam., not beaked…C. capsularis.
Capsule elongated 3-8 cm. long, beaked…C. olitorius.
Jute is a rainy season crop. It prefers an alluvial soil although it can be grown in other types of soil. The soil is prepared by ploughing 5 or 6 times and all clods of earth should be broken to fine particles. Seeds are then sowed by broad-tasting or sometimes by dibbling.
Cow dung and wood ash is liberally applied to the soil before sowing. The seeds are sown during March to May and germinate when they receive a pre-monsoon shower. Weeding and thinning is necessary at seedling stage and the land is harrowed with a rake.
Weeding operation is done 2-3 times and after final thinning the spacing between the plants is 10-15 cm. wide. The plants are unaffected by water standing on the field due to excess rainfall but at seedling stage water logging is harmful.
Manuring with sulphate of ammonia, potash and lime results in a quick growth. Harvesting is done after 60-90 days when the pods are still green or at flowering stage. The plants are cut down very near to the base tied into bundles and carried to a pool or a canal of slow running water.
The bundles are arranged in 2 or 3 layers. Logs, psudostems of banana and mud are put on the floating layers as weights. Complete submersion is essential. In a period of 10-15 days the soft tissues of the stem disintigrates and the fibre-strands separate from the woody portion.
Fibres are then stripped out and washed and are spread in the sun for drying for 2 to 3 days. The bundles of fibres are then made into bales and stored or sent to the market. The average yield per acre is about 600 kg. The chief jute growing areas in India lie in W. Bengal and Assam.
The crop is raised in Bihar. U.P. and Orissa also and in smaller scales in Andhra Pradesh. Outside India major jute producing countries are Bangladesh, Ceylon, Nepal, Siam, China and Taiwan and also some parts of Africa and in Brazil.
Land under jute cultivation in India is about 1200000 acres and the jute obtained each year is about 3 million bales of 200 kg. each. About 70% of jute produced in India is exported outside every year. The jute is used for the manufacture of hesian, ropes, etc.
The woody material or the sticks after the removal of the fibres are also made use of in different ways. They are good as fuel and are much in demand in the field of betel vine. The vines are grown in partial shade under a roof covered by the jute-sticks.
The sticks are also used as supports of betel vine and also other climbers producing vegetables. The leaves of C. olitorius are used as pot herbs and leaves are collected from the seedlings which are uprooted in thinning operation. They are also considered to have some medicinal value.
Fibre Plant # 2. Cotton (Gossypium Species):
The cotton fibre is the hairy outgrowth of the seed of different species of Gossypium Linn.
Those cultivated in India for the fibre are:
1. G. arboreum Linn.
2. G. herbaceum Linn.
3. G. barbadens Linn.
4. G. hirsutum Linn.
The first 2 are old world species and are diploid having chromosome number, n = 13. The other 2 are New world species and tetraploid with n = 26.
The genus Gossypium is described below:
Shrubs or short trees. Leaves simple, palmately lobed, alternate, stipulate; stipules 2, lateral. Flowers solitary on jointed peduncles, axillary, regular, hermaphrodite, large, yellow, usually with crimson or purple centre; bracteoles 3, large, leafy, cordate, broadly ovate, deeply toothed or laciniate near apex, persistent.
Calyx cupular, truncate or slightly 5 – toothed. Petals 5, slightly conate at base and adnate below to the staminal column. Stamens numerous, connate in a tube which is truncate or 5 – toothed at the top and giving off below the apex many short antheriferous filaments; anthers 1 – celled, reniform, dehiscence longitudinal, extrose.
Disc small, Carpels 5, syncarpous, forming a superior 5 – locular ovary; ovules many in each cell on axile placenta; style clavate, 5 – grooved at the apex with 5 stigmas. Fruit a 3-5 valved capsule; seeds densely clothed with wooly hairs.
i. G. arboreum:
Shruby, younger parts finely pubescent. Leaves deeply cut into 3-7 lobes. Bracteoles triangular, longer than broad, entire or with 3-4 coarse teeth. Capsule tapering, profusely pitted, 3-4 locular, opening widely. Seeds with 2 coats of haris. Old world species, found wild and cultivated in Africa, Arabia, India, China, Japan and Malaysia.
ii. G. herbaceum:
Herbaceous or shru by, 1.7 mtr to 2.5 mtr high, sparsely hairy, or glabrous. Leaves cleft to the middle, 1-7-lobed. Bracteoles triangular, usually broader than long, with 6-8 teeth, loosely attached to the flower or capsule.
Capsules rounded, with few oil glands, opening slightly when ripe. Seeds with 2 coats of hairs. Old world species, found wild and cultivated in Africa, Middle East and Central Asia and Western India; cultivated in China.
iii. G. hirsutum:
Shrubes or short trees, 1-5 mtr high. Leaves ovate-cordate, with 3-5 acuminate lobes. Bracteoles ovatecordate, longer than broad, with 7-12 acuminate teeth. Capsules rounded, 3-5 locular, oilglands few and inconspicuous. New world species, found in India and other Asiatic and African countries only in cultivation. Different races are known in cultivation and some are annual.
iv. G. barbadense:
Shrubs or small trees, up to 5 mtr. high, glabrous to densely hairy. Leaves with 3-5 long tapering lobes. Bracteoles as broad as long, cordate, with 10-15 long acuminate teeth. Capsules 3-4-locular, broad at base, ‘acute, rough and pitted. New world species cultivated in African and Asiatic countries. Annual races are known in cultivation.
It is considered that the Indians were the first to utilise cotton for manufacturing fabrics and to cultivate cotton plant for that purpose. Evidences from Mohenjo-Daro establish beyond doubt that the people were accustomed to use cotton garments produced locally.
Therefore it is safe to say that cultivation of cotton plant started before 3000 B.C. in Western India. From India it spread to other Asiatic countries and to North Africa. American species of Gossypium were rather recently introduced, and many races evolved, some as natural hybrids and some by horticultural manipulations and researches.
Cotton plant prefers a hot and comparatively dry climate. Summer temperature not exceeding 44°c and a mild winter are well suited for cotton growing. It cannot stand frost and cannot tolerate heavy rainfall. Although adequate moisture is required in early stages of growth of the plant drier climate is good at flowering stage and rainfall is harmful at ripening period.
The black cotton soil of western and central India and the red soil of S. India are very suitable for cotton cultivation. The former type is deep heavy and black soil rather clayey, cracking when dry, swelling and loosening after rains. This type of soil contains calcium and low in organic matters.
This soil is very fertile and retains moisture and cotton is grown here under rain-fed condition. Red soil is light, porous and friable, contains much iron and alumina and less of calcium. American races are usually grown on such soil under irrigated condition. Clayey or sandy alluvial soil of Indo-Gangetic plain is also suitable for cotton cultivation.
Land is prepared by ploughing and harrowing 2-3 times with a blade-harrow. Seeds are then sown in lines with wooden seed drillers or by broadcasting. Seeds are pre-treated with mud and cow dung. Delinting with chemicals is also recommended.
Soaking the seeds in water for 12-24 hours is also practiced as it facilitates germination. Seeds are sown in summer from April to June usually after the first shower? plants are thinned out when one or one and half month old so that the spacing between the plants is 30-100 cm.
American plants are sometimes topped when about 1 mtr tall to induce branching. Small quantities of farm yard manure or oil cakes are applied. If the soil is not saline and rainfall is adequate nitrogenous fertilizers and organic manures are given. Rotation of crops is usually practiced with wheat or jowar after the cotton is harvested.
Flowering starts after about 2 months or more and the boll or the fruit attains full size in a period of about 4 weeks. Three to four pickings are done from a field as the blooming is not simultaneous and all fruits are not fully ripe at one time. In rain-fed areas the yield is 15-70 kg. per acre while in irrigated fields it is much more, about 125 kg per acre.
Wilt and root rot are the two serious diseases of cotton plant. As these are seed borne diseases seed treatment is necessary for the control. Seeds are immersed for 1 hr. in 0.25% Uspulum, or are dusted with the same.
Delinting with sulphuric acid also gives good result. Spraying of Bordeaux mixture in the field when the plants are at seedling stage is recommended. G. hirsutum and G. barbadense are immune to such diseases in India and there are some wilt resistant strains of other species. Selection from amongst these for cultivation eliminates the diseases.
Ginning is done in factories by power-driven machines but in villages charkha gins are still in use. After ginning the cotton is compressed into bales each weighing about 175 kg. The total production is about 4298000 bales every year while total area under cotton cultivation is about 18346000 acre.
Fibre Plant # 3. Sisal Hemp (Agave Sisalana Perr):
Sisal hemp are shrubby herbs with usually a very short thick woody root stock. Leaves are large, thick and fleshy, densely clustered at the top of the root stock, bluish green, spiny at the tip and at the edges; 1.5 – 2 mtr. long and about 15 cm. broad.
Inflorescence is a long thyroid panicle on a stout pole like peduncle arising from the centre of the plant and rapidly growing to a height of 7-10 mtr. Flowers bisexual, with a tubular perianth. Stamens 6; filaments adnate to the base of and longer than the perianth.
Carpels 3; ovary inferior, 3-celled with many ovules in each cell; style filiform; stigma 3-lobed. Fruit an ovoid capsule; seeds many, flattened, cuneate, with a black testa. Fruit sometimes replaced by viviparous bulbils.
Agave flowers only once in their life time and the plant dies after fruiting. On cutting the young peduncle a large quantity of sugary juice is obtained. The fibres are obtained from the leaves and are bast fibres. Besides A. sisalana, two other species are cultivated in India, e.g. A. americana Linn. (Syn. A. cantala Roxb.) and A. vera-cruz Mill. The leaves of these 2 species are smaller than those of A. sisalana.
Agave plants are indigenous to Tropical America wherefrom these were introduced to India by the Portugese in the 15th century. In this country cultivation of Agave was not taken up at the beginning for fibre production but occasionally it was cultivated as a hedge plant. Cultivation on a commercial scale was taken up only in the middle of this century.
The plants prefer a hot and more or less dry climate and grow on clayey, gravelly or sandy soil. They are propagated by bulbils or by suckers. Not much care is taken to grow the plants which start producing full size leaves in course of 3-4 years.
The leaves are then collected from time to time, few at a time from each plant which continues to grow for several years. The leaves are crushed in the crushing mills and the fibrous materials are retted in water, washed and dried.
The fibres are made into ropes and woven into a type of hesian cloth for making sacks and bags. Agave fibres or Sisal hemp does not rot in water and for this Sisal-rope is in great demand in the navy.