Rearing Performance of Muga Silkworm as Influenced by Abiotic Factors during Commercial Crops at Garo Hills Region

Author: Vikram Kumar, M. Majumdar, A. Singh, K. Indirakumar, Narendra Kumar and K. Neog

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Abstract

Muga silkworm (Antheraea assamensis Helfer) is multivoltine, i.e. 5-6 times rearing of the silkworm can be done in a year. Muga silkworms are reared during the autumn and spring seasons which are termed as ‘Kotia’ and ‘Jethua’ crops, respectively. The cocoons produced during these two seasons are used for producing yarn commercially and hence, these two crops are called commercial crops. ‘Kotia’ commercial crop rearing is preceded by one crop rearing during June-July which is called ‘Aherua’ pre-seed crop and subsequent rearing during August-September is called ‘Bhodia’ seed crop. Similarly, ‘Jethua’ commercial crop rearing is preceded by ‘Jarua’ (December-January) pre-seed crop rearing followed by ‘Chatua’ seed crop rearing. The pre-seed and seed crops of Muga usually fall in adverse climatic seasons of extreme summer and winter and the productivity sometimes slashes down to 10- 20%. The present study was conducted on the effect of abiotic factors on commercial season among Jethua and Kotia in muga silkworm with respect to its rearing performance in Garo Hills. From the study (based on three-year data) it is revealed that the Kotia season recorded a significantly high Effective Rate of Rearing (pooled t-value is 20.79) as compared with the Jethua commercial crop while hatching percentage, larval period, male weight and female weight was statistically at par with both the commercial crop season. Heavy rainfall during brushing, hailstorms during the early stage, temperature fluctuations and high rainfall are the climatic factors which badly affect muga silkworm in the Jethua crop. Based on meteorological parameters it is advisable that the preponement of Jethua crop rearing may give them a good harvest as compared to the existing crop schedule. Based on the rearing performance it is also suggested that farmers of Garo Hills may increase the quantity of muga silkworm rearing in Kotia crops so they can earn more profit from practising muga culture.

Keywords

Muga, Jethua, Kotia and Rearing performance

Conclusion

India is a sub-tropical country and environmental conditions are the limiting factors of muga silkworm rearing. Majority of muga rearers encounters the various environmental problems and lose their crops or produce inferior quality of cocoon and silk. Based on the experiments, Jethua crop recorded lower effective rate of rearing and statically at par larval weight, larval duration and hatching percentage with Kotia crop, due to heavy rain and hailstorms at their early stage worms. High incidence of bacterial and viral diseases was also observed in Jethua crops late age rearing due to high temperature fluctuations. By all the above modification and suggestion, muga silkworm rearing may be conduct and quality of cocoons and silk can be improved where environmental variation is less.

References

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How to cite this article

Vikram Kumar, M. Majumdar, A. Singh, K. Indirakumar, Narendra Kumar and K. Neog (2024). Rearing Performance of Muga Silkworm as Influenced by Abiotic Factors during Commercial Crops at Garo Hills Region. Biological Forum – An International Journal, 16(2): 98-101.