Evaluation of some productive hybrids of Bombyx mori L. suitable for the autumn seasons in the rainfed condition of Assam, India.

Three mulberry silkworm breed viz. CSR2 X CSR4 (EIV52.55673), APS45 x APS12 (EIV51.27833) and GEN3 X GEN2 (EIV50.01986) has been identified as the most promising for commercial exploitation in agroclimatic condition of North eastern region of India by uemploying the Evaluation index method. In India, in recent times, the Evaluation index method for a particular trait or character is widely used by the silkworm breeders and a cumulative score of all the characters ranks the hybrids based on higher score. The sum of index values with regard to all the characters allotted to an hybrid indicates the hybrid's worth. During the present study, by employing the Evaluation index method six bivoltine hybrids were evaluated based on their performance at 24±3°C and 25±5°C and 79±2% relative humidity. The hybrids were ranked as per the cumulative score and the value of a particular trait in a particular hybrid were compared with the ranking.