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Chawki Rearing Centre (CRC)

A Chawki Rearing Centre (CRC) is a registered facility that incubates disease-free layings and rears mulberry silkworms through the first two larval instars (the "chawki" or young-age stage) under controlled environmental conditions, then supplies vigorous chawki worms to farmers for late-age rearing.

Overview

The CRC system was set up to improve cocoon yields by overcoming the difficulty individual rearers face in maintaining the precise temperature, humidity and disinfection required for young-age worms. CSRTI Mysore and CSRTI Berhampore have published detailed package-of-practices and design guidelines for commercial CRCs.

Eligibility

CRCs operate under the Central Silk Board (Amendment) Act, 2006. About 800 CRCs are registered across the major sericulture states. Operators are licensed by the Central Silk Board and state sericulture departments; they typically maintain dedicated chawki mulberry gardens of recommended varieties (see Mulberry Cultivation Sericulture) to supply tender leaves of suitable maturity.

Benefit and structure

A CRC procures certified Disease Free Layings Dfl and rears the young worms through black-boxing, brushing, leaf preparation, instar moults and the second-instar moult before handing over 6-7 day old worms to farmers. Demonstrations report about 89% survival of CRC-supplied chawki worms compared with around 61% for farmer-incubated outdoor rearing. The improvement is attributed to disinfected rearing rooms, uniform leaf quality and disease-free seed handling. Capital subsidies for CRC establishment are available under central and state sericulture schemes.

Implementation

The standard CRC process covers egg incubation in dark rooms (black-boxing), synchronised hatching, brushing onto rearing trays, four feeds per day of finely chopped tender leaf, and bed disinfection between feeds. After the second moult the chawki worms are graded and packed for transport to commercial rearers, who carry on with late-age rearing in their own Silkworm Rearing Shed using whole-shoot feeding and bivoltine hybrids (Bivoltine Silkworm).

See also: Disease Free Layings Dfl, Bivoltine Silkworm, Mulberry Cultivation Sericulture, Silkworm Rearing Shed, Chandrika Mountage.

References

  1. Chawki Rearing. CSRTI Berhampore.
  2. Commercial Chawki Rearing. CSRTI Mysore.
  3. Economic Evaluation of Chawki Rearing Centres. International Journal of Research in Agronomy.