The following points highlight the top four fibre crops that are found in India. The fibre crops are: 1. Ramie 2. Sisal 3. Sunnhemp 4. Mesta.
Fibre Crop # 1. Ramie:
Ramie (Boehmeria nivea) is perennial bushy shrub of the family Urticaceae. The plant produces longest and strongest fibers for commercial use least affected by moisture. It is used in the manufacture of valuable garments, currency notes, army uniform, suiting, table cloth, napkins, fishnet twines, gas mantles etc.
It is indigenous to central and western China, Indonesia and India. Since viable plantation requires large investments at a minimum of 40 ha, small holdings arc unfit for commercial production.
Ramie requires a warm and humid climate for optimum growth and yield. It cannot tolerate waterlogging and low temperature. A well distributed rainfall of 1500 -2500 mm is ideal. North of Bengal, Assam, foothills of Meghalaya and Western Ghats are suitable for its cultivation.
Ramie is unisexual and monocious. Rhizomes are used for propagation. Rhizome cuttings at 200 kg ha-1 are planted with a spacing of 100 x 50 cm. Optimum planting time in northeastern India is April-May. Improved varieties are R 1449, R 1452, R 1411 and R 67-34.
At each point of planting, a clump of 8-12 canes (stems) develops. The first year’s growth will not be uniform. Hence, it is cut back close to the ground level in April. From the second year, 5-6 cuttings (harvests) are taken at about 55 days interval yielding around 1,200-1,600 kg of under gummed dry fibre ha-1 yr-1. The plantation is replanted once in 7-8 years. Each cutting is followed by application of ramie compost and NPK.
Fibre cannot be extracted by normal retting procedure. The fibre is first squeezed out by decortication in a machine and dried in the sun. Then the decorticated fibres are extracted by chemical retting called degumming. In this process, gummy and pectinous materials are removed by boiling in a bath with caustic soda, sodium phosphate and other catalysts followed by several processes. Degumming is a trade secret.
Plant height, basal dia and percentage of fibre are considered as yield components as in the case of other bast fibres like jute, mesta, roselle etc. In ramie, the fibre is obtained from the bast but it occupies very scanty area. The percentage of fibre is also very small (2%). The textile value of ramie is remarkable for its silky lustre, unparalled strength and durability, its suitability as blends with terene, rayon, silk, muga, flax, wool for shirtings, hose-pipes etc.
Fibre Crop # 2. Sisal:
Sisal or agave (Agave sisalana), introduced from Mexico, is a semi-perinnial plant yielding cream white fibre from leaves. The other two species grown in India to a very limited extent are Agave cantala and Agave Veracruz. Generally, agave is grown as a live fence around plantations. In the recent past, it has been recommended as a live bund in soil and moisture conservation, especially in watershed programmes.
In India, agave is mainly concentrated in drier areas of Bihar, Orissa, Maharashtra, Karnataka, Andhra Pradesh and Madhya Pradesh. Annual production is estimated around 12,000 t. Annually, India imports agave worth Rs 3 crores from Tanzania and Kenya. However, it exports agave ropes, twines, carpets, nets etc. to other countries.
The plant, popularly known as the century plant, has a short thick stem (bole), which is almost concealed in early stages by the surrounding sessile leaves, which are thick, broad and very long. From slender rhizomes, buds grow and sprought above the ground to form the baby plants or suckers. The plant flowers at the age around 8 years.
The stought floral axis develops slowly and produces flowers, which drop off and bulbils or baby plants develop on the seat of flowers. Both bulbils and suckers furnish the propagation material for the plantation. Improved variety is Leela (hybrid).
Bulbils and suckers are maintained in a nursery bed. They can be transplanted when they are 10-18 months old with a spacing of 50 cm between the plants. Depending on the growth, leaves can be harvested from 2-3 years old plants annually.
Retting is the common method of fibre extraction. If the area is relatively more, power driven decatrticalors are used for fibre extraction. In general, the yield ranges from 1.5 to 2 t ha-1. Well managed crop in areas of good rainfall can yield the fibre up to 3 t ha-1. Planting material can be obtained from Sisal Research Station, Bamra, Orissa. Fibre is used for making ropes, mattresses, brushes, door mats and several fancy articles.
Fibre Crop # 3. Sunnhemp:
Sunnhemp (Crotalaria juncea) Bombay hemp or Banaras hemp is grown for the bast fibre. It is also a green manure crop and a minor fodder crop. The area under sunnhemp is around 1,50,000 ha with a fibre production of 60,000 t annually. The crop can be grown all over the country. Uttar Pradesh and Madhya Pradesh are the two major states producing sunnhemp fibre.
Sunnhemp is a tropical crop grown during kharif in north India and throughout the year in south India. A minimum of 400 mm rainfall with equal distribution during the crop period is ideal.
Since jute and mesta are the two major crops of economic importance in fibre production, adequate attention has not been initiated to develop high fibre yielding sunnhemp varieties.
However, the following are the important fibre producing varieties in different states:
Uttar Pradesh: Kanpur 12.
Madhya Pradesh: M 35, M 19, M 18.
Bihar: Nalanda sanai.
Tamil Nadu: Bellary.
Maharashtra: D IX
West Bengal: ST 55, SH 4.
The seed is usually sown by broadcasting 25 kg ha-1 Row seeding (30 cm) requires a seed rate of 15 kg ha-1. Generally, phosphorus and potassium are applied through fertilisers at 25 kg ha-1 each as basal dose at seeding.
Pod formation (120- 140 DAS) is considered optimum stage of harvest for fibre. The plants are cut with sickles and the bundles are retained in the field for 2-3 days for the leaves to be shed. The process of retting and extraction of fibre are similar to that of jute. Fibre yield is around 400 kg ha-1. However, a well-managed crop can yield up to 1,500 kg ha-1.
The fibre is dull yellow, somewhat coarse, strong and durable. Due to high cellulose content, low lignin, the fibre is used in the manufacture of tissue paper and paper currency. In rural areas, it is used for making ropes, twines and nets. Sunnhemp fibre is not used for textile purposes, unlike jute and mesta.
In India, fibre yielding plants of commercial importance are jute, mesta, roselle and sunnhemp among bast fibres and cotton as textile fibre.
Other fibre yielding plants of considerable local importance are:
Fibre Crop # 4. Mesta:
Two species of Hibiscus, H.cannabinus, (HC) and H.subdariffa (HS) var altissia are commercially known as Mesta or kenaf. Mesta is also known as Bimili jute, Deccan hemp or Java jute. The HS is also called Siami jute in Thailand and roselle in India. Both the HC and HS are important jute supplements and show wide adaptability unlike jute. At present, both the species are known as Mesta. Fibre is extracted from barks (bark fibre) of the two species (HS and HC).
H.cannabinus (HC) plant is hermoprodite and annual, mostly with bristles. Stem glabrous and prickly. Lower leaves entire, cordite, upper leaves deeply palmate loabed, lobes narrow and serrate. Flowers are large, cream coloured with reddish purple or scarlet throat. Flowers open before sun rise and close before noon on the same day. The HC is a short day plant (sensitive to day length) and ceases to grow when the day lengths are below 12.30 hrs. The growing period ranges from 110 to 140 days.
H.subdariffa (HS), a roselle like Mesta, is a substitute to jute but in quality it is inferior to jute. Plants are annual and unarmed. Stem is generally purplish, leaves polymorphous, typically pinnate, deeply lobed (3-5 lobes) and alternate on stem. Flowers are smaller than those of HC, cream to light yellow having a scarlet to magenta colored throat. Plants are generally non branching.
The crop is late maturing with a duration of 150 to 180 days. It can stand warmer and humid weather and more tolerant to drought rather than HC. It require a long vegetative period of 280 to 237 days when sown from mid-March to mid-May and do not mature before the second week of November irrespective of sowing date.