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Paragraph on Sericulture!
The rearing of silkworms for the production of raw silk is known as sericulture. The Chinese people knew the methods of cultivating silk and preparing cloth from it for more than 2000 years. But the art of sericulture was held by them a very close secret, so much so, that leakage of any information or attempt to export eggs or living cocoons was punishable with death.
Even then silk was after all introduced in Europe by two monks, who were sent to China as spies. They studied the nature, source, and art of silk-rearing and stealthily carried some eggs in their pilgrim’s staff to Constantinople in 555 A.D. From this place the silk-rearing spread into Mediterranean and Asiatic countries including India, Myanmar, Thailand and Japan.
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Nowadays, sericulture is an important industry of several Asian and European countries, but China and Japan are the only great producers of raw-silk. No government in this world can profit by its silk-industry except providing employment to half a dozen people per acre of mulberry or part-time work to farmers.
A rough estimate in India reveals that this industry is providing work to about 5 million people with an annual income amounting to Rs. 19 crores. The total production is about 2.5 million pounds as against a demand of about 4.2 million pounds per year. Silk industry in India has drawn the attention of the Government of India considerably.
In 1934 an Imperial Sericulture Committee was formed and since 1939 an All India Sericulture Conference meets every year. Important research work is being undertaken on problems of production of silk, the processes of spinning, reeling, preparing yarn and cloth in Assam, Bengal, Madras, Punjab, Kashmir and Mysore, etc.
Research is also in progress regarding the production and supply of healthy eggs, refrigeration, etiology, hybridisation and breeding studies besides the propagation and cropping of mulberry varieties.
Sericulture thrives in China, Japan and France also but not in America because this involves plenty of manual labour which is not as cheap in America as in China, Japan and India, etc., besides silk can hardly compete with synthetic fibres.
Sericulture is a regular industry in India and it has silk-producing centres in Assam, Bengal, Madras, Punjab, Kashmir and Mysore. Healthy eggs of high yielding strains are procured from sericulture research stations. The hatching of the eggs can be controlled (accelerated or postponed) artificially by proper conditions of refrigeration.
The eggs are placed in paper-lined trays made of split bamboo. The trays are kept on stools, the legs of which rest in dishes containing water to make them ant-proof. The eggs are periodically stirred by a feather. Larvae are given chopped mulberry leaves 5 to 9 times per day during the larval period which lasts for 3 to 5 weeks in which larvae moult four times.
The pupae are not allowed to become adult. To procure silk, the cocoons, before the emergence of the silk-moth, i.e., 8 to 10 days after the cocoon formation, are dropped in hot water or subjected to steam or dry heat or fumigation. Sometimes they are killed by sunning for 4-5 days called stifling.
This results in killing the pupae. After assorting the cocoons with respect to their texture and colour, they are skillfully unwound by experts. Soaking cocoons in boiling water, helps in softening the cement or adhesion of the silk-threads among themselves and in loosening the outer threads to separate freely.
After the loose strands have been removed by a revolving brush, free ends from four or five cocoons are passed through eyelets and guides to twist into one thread and wound round a large wheel, from which it is transferred to spools. This is known as raw-silk or reeled silk.
The raw silk is again boiled, stretched and purified by acids or by fermentation. It is then carefully washed several times to bring about the well-known silk lustre on the thread. It is then supn and woven into fabrics which we most proudly prize.
The waste outer layers or superficial threads and damaged cocoons, etc., are combed, teased and then the filaments are spun. This product is known as spun silk. About 40 to 50 million kilograms of raw silk is consumed in the world annually. Indian consumption is estimated to be about 2 million kilograms of silk and production only 1-1.5 million kilograms per year, the half of which is the production of Mysore only.
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One cocoon yields about 300 metres of silk thread. It requires about 25,000 cocoons to prepare a half a kilogram of finished silk. An idea of the total number of cocoons sacrificed every year for the benefit of human race can be had from the fact that about 40 to 50 million kilograms of silk is consumed annually in the world.
