~ 757 ~ International Journal of Research in Agronomy 2024; 7(6): 757-761 E-ISSN: 2618-0618 P-ISSN: 2618-060X © Agronomy www.agronomyjournals.com 2024; 7(6): 757-761 Received: 26-04-2024 Accepted: 27-05-2024 Aroos Rauf Rafiqui College of Temperate Sericulture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Jammu and Kashmir, India Irfan Latif Khan College of Temperate Sericulture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Jammu and Kashmir, India Omais Bin Ayoub College of Temperate Sericulture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Jammu and Kashmir, India Mohd Rafiq Bhat Department of Sericulture, Forest College and Research Institute, Tamil Nadu Agricultural University, Coimbatore Ovais Ahmad Hajam College of Temperate Sericulture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Jammu and Kashmir, India Corresponding Author: Omais Bin Ayoub College of Temperate Sericulture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Jammu and Kashmir, India Impact of feeding different mulberry varieties during chawki rearing on commercial characteristics of silkworm, Bombyx mori L. Aroos Rauf Rafiqui, Irfan Latif Khan, Omais Bin Ayoub, Mohd Rafiq Bhat and Ovais Ahmad Hajam DOI: https://doi.org/10.33545/2618060X.2024.v7.i6j.2484 Abstract Silkworm (Bombyx mori L.) being a monophagous insect feeds solely on mulberry leaves (Morus spp.).The insect undergoes five instars during its larval phase with four moults and its rearing is divided into two stages: chawki rearing (rearing of first two instars) and late-age rearing (rearing of subsequent three instars). Among many interlinked factors that decide the success of silkworm rearing, young age silkworm rearing (chawki rearing) technique is the most important one and has the closest bearing on the stabilization of cocoon crop as well as on productivity. The contribution of chawki rearing technology to the remarkable increase in the cocoon productivity cannot be neglected as more than 80 per cent of silkworm rearing, especially in Southern India depends on chawki reared worms. Since mulberry leaf is the only source of nourishment to silkworms, its quality plays an important role in improving the growth and development of the silkworm. In order to assess the performance of mulberry genotypes aimed at selection of superior varieties for rearing performance, a study was conducted to evaluate five different mulberry varieties viz., Ichinose, KNG, Goshoerami, Koksu-21 and Tr-10 when fed during chawki rearing on the commercial characteristics of silkworm. The study revealed that KNG outperformed other varieties in terms of enhancing silkworm growth and productivity with better mature larval weight (37.41g), shorter total larval duration (689hrs), cocoon yield per 10,000 larvae by number (9405) and weight (15.30kg), single cocoon weight (1.65g), shell weight (0.34g) and shell percentage (20.61). Keywords: Silkworm, chawki, mulberry, commercial. Introduction Silkworm, Bombyx mori L., is an economic insect which produces silk-Queen of Textiles renowned globally for its unparalleled luster and elegance. The insect feeds exclusively on mulberry (Morus spp.) leaves which play a pivotal role in its growth and development. Since the environmental and nutritional requirements of the worms vary with developmental stages, silkworm rearing is generally categorized into- young-age (chawki) rearing (rearing first and second instar larvae) and late-age rearing (rearing third, fourth and fifth instar larvae).Though of the total leaf requirement, only 4 to 5 per cent is consumed during first two instars, yet the rate of growth per given time is the highest in first instar which gradually decreases with the advancement in age (Aruga, 1994) [4] . Kumar (2012) [14] reported that among the first three instars, the growth rate is fastest during first instar (15 times in 50 hr of feeding period), second instar (5 times in 45 hr of feeding period) and third instar (3 times in 60 hr feeding period). Similarly, the oxygen intake and evaporation per unit body weight are highest in the first instar. Therefore, the relevance of chawki rearing in determining the success of late age rearing can’t be overlooked as it establishes a critical foundation for the larval growth, development and general health which directly influences the economic traits of the silkworm (Yokoyama, 1975; Krishnaswami et al., 1970; Chaluvachari, 1995) [20, 13, 7] . The insect extracts all the nutrients from the leaf (Bahar et al., 2010) [6] and the contribution of mulberry leaves towards the success of silkworm rearing is 38.2 per cent (Miyashita,1986) [16] . Hence, identification of suitable mulberry varieties to optimize the performance of silkworms becomes a prerequisite to stabilize sericulture industry. The best evaluator of mulberry is the