Introduction
Jute fiber and allied fiber crops constitute a formidable group of vegetable fibers catering to various requirements of people, apart from generating sizable employment and contributing significantly to the national exchequer of growing countries through the export of jute goods. Based on botanical origin, the two cultivated species of jute out of eight species discovered so far – Corchorus olitorius L. (Tossa jute) and Corchorus capsularies L. (white jute) constitute the world’s foremost bast fiber cash crops and the second most important textile fiber next to cotton. Jute is mainly grown in South East Asian countries like India, Bangladesh, China, Nepal, Indonesia, Thailand, Myanmar, and some South American countries.
In India jute is grown in the Eastern region covering over 0.8 million hectares, producing 1.8 million tons of fiber including the production of two cultivated species of Mesta (Hibiscus cannabinus L. and Hibiscus sabdariffa L.) which is about 50% of world production. The share of Mesta is about 15% of the total jute production in India.
The major jute and Mesta producing states are West Bengal, Assam, Bihar, Orissa, Meghalaya, Tripura, and Andhra Pradesh. Jute being a labor-intensive crop, about 40 lakh farm families derives their sustenance by cultivating jute in the country. Moreover, 2.5 lakh people are employed in the organized jute industry, and over 25 lakhs people are engaged in jute based ancillary and jute diversified sectors. India earns annually about 1200 crore rupees as a foreign exchange by exporting various jute products. The cultivation of jute improves soil fertility status by shedding its leaves in the field. The crop also suits well in crop rotation.
Thus the production of jute fiber assumes high socio-economic significance in our country. Jute is also known as the golden fiber of India.
Jute seed
The golden fibers are cultivated by sowing seeds in the fields. Meanwhile, the annual requirement of certified seed in India is about 5000 tonnes. However, about 4% of total jute plants cultivated annually is left for seed production. To achieve higher yield and better quality fiber, different varieties of jute seeds for both Corchorus olitorius and Corchorus capsularies have been evolved in jute producing countries, particularly in India.
It is interesting to mention that one Indian variety (JRO-524, called Naveen) is saturated with over 80% area of crop cultivation in the world.
Biotechnology has been playing a major role in jute seed research to –
(i) Increase jute productivity
(ii) Improve fiber quality
(iii) Broaden Tolerance of crop for drought, salinity, and other abiotic stresses
(iv) Enhance resistance of jute crop to pests and diseases etc.
Agro-metrology and Retting
The jute crop responds favorably to high relative humidity (70–74%). The annual rainfall preferred for favorable growth is 1500 mm or more with at least 250 mm of monthly precipitation during each month of March, April, and May to maintain appropriate soil moisture.
The requirement regarding the range of mean temperature is 30–350C. More than 75% of jute is grown in the northern hemisphere between March and September. Jute grows well in loam and clay-loam soil with a pH range of 6.2 -7.2. the crop is harvested at around 110-120 days or as soon as flowering starts.
Modern agriculture requires efficient sustainable and environmentally sound management practices. Therefore Sustainable agriculture with due consideration of the undermentioned points aims not only in increasing crop yield but also in maintaining or improving the natural Eco base.
a) Management of nutrients and soil health
b) Water management
c) Weed management
d) Pest management
e) Disease management
Retting & Fibre Extraction
Conventionally retting is the total process of loosening of fiber strands from the woody core by decomposing the non-fibrous matters linking the fibers to the bark with the help of aquatic microbes when put into water bodies for about fifteen days, mechanical extraction of fibers, washing, and drying of jute fibers before marketing of the same.
Retting plays an important role in quality fiber production. As the conventional whole plant retting does not suit the farmers in the water crisis situation, mechano-microbial retting technology has been developed which needs some more studies for commercialization.
However, under the mechano-microbial method, green bark containing the fiber bundles is extracted from jute stems by a mechanical device.
Then the extracted green ribbons are then sprayed with a microbial consortium and kept overnight covered with a polythene sheet. the next morning, sprayed ribbons are steeped vertically in polythene lined pit for retting, and retting is completed in about seven days.
The efficiency of retting and quality of fiber depends on factors like crop age, fertilization of crop, quality of retting water including pH and temperature, activators, covering materials, etc.
There are other techniques like dew retting and chemical retting. The fibers are extracted, the inner woody portion of the jute plants is used as fuel in the rural areas or can be converted into particle board (composite) for technical applications.
Structure and properties
Commercial jute varies from yellow to brown to dirty grey in color, and it has a natural silky luster. Jute usually feels coarse and rough to the touch, although the best qualities are smooth and soft. Retting destroys the cellular tissue that holds the bast bundles together but does not normally separate the individual cells one from another.
The individual cells of jute are about 2 -6mm (l/10th in) long, on average. Seen in cross-section, the cell is polygonal, usually with five or six sides. It has thick walls and a broad lumen of oval cross-section. Seen in cross-section, the cell is polygonal, usually with five or six sides.
It has thick walls and a broad lumen of oval cross-section.
Towards the ends of the cell, which are tapered, the lumen widens; the cell walls become
Correspondingly thin. Jute contains about 20 percent of lignin.
Tensile Strength
Jute is not so strong as flax or hemp, nor is it so durable. Individual
fibers vary greatly in strength, owing to the irregularities in the
thickness of the cell walls.
Elongation
Jute fibers do not stretch to any appreciable extent. Jute has an
elongation at break of about 1 -7 percent.
Elastic Properties
Jute tends to be a stiff fiber, owing to the part played by the material
which cements the cells together.
Specific Gravity. 1-5.
Effects of Moisture
Jute is an unusually hygroscopic fiber. Its regain figure is 13-75 percent. However, it can absorb as much as 23 percent of water under humid
conditions.
Effect of Age
If kept dry, jute will last indefinitely although the high content of
non-cellulosic matter tends to make it sensitive to chemical and
photochemical attack. Meanwhile, moisture encourages deterioration of jute,
which loses strength with age.
Micro-organisms
Jute is more resistant to rot than either grey cotton or flax (i.e.
uncleaned or unscoured).
USES OF JUTE
Jute is cheap and reasonably strong and is available in large quantities.
These characteristics have enabled it to become an important fiber for sacks and packing clothes.
On the other hand, finer qualities of jute are made into curtains and furnishing fabrics
mixed with wool, after treatment with caustic soda, jute is
spun and woven into cheap clothing fabrics.
Familiar uses for jute include the following:
- Sacks, bags, baling and bundle cloths, wrappings (e.g. for bacon), bedding foundations,
bonded fabrics, boot, and shoe linings. - Likewise, it is used for strings for all purposes, certain ropings, wall coverings, wool packs, etc.
- Starched and glued buckrams, and tailor’s black packings, camp beds, cargo, and other separation cloths (e.g. in rubber technology), cattle beddings, concrete cleavage fabrics.
- Tarpaulins, damp courses, cables, plastics reinforcement, filter cloths, fire curtains, fuse yarns, furnishings, handbag.
- All types of stiff bag and case linings, hop pockets, horse covers, aprons of all heavy types, iron.
