Effect of graded level of nutrients on tree mulberry and it’s influence on cocoon parameters of FC1 and FC2 breeds of silkworm Bombyx mori L

This study aimed to determine the optimal nutrient combination for maximizing silkworm seed cocoon yield in tree mulberry cultivation by examining the effects of Farm Yard Manure (FYM), NPK fertilizer, and foliar spray on single cocoon weight, shell weight, and pupal weight in FC 1 and FC 2 silkworm breeds. Significant differences in Effective Rate of Rearing (ERR) were observed across 16 treatments, with the highest values in T7, T8, T14, T15, and T16 reaching 97.02%, and 97.75% ERR in FC2 breed for T8, T15, and T16. The optimal combination (40 t FYM/ha/yr + 125% RDF + foliar spray) yielded the highest cocoon weights (2.09 g for FC 1 and 2.20 g for FC 2), shell weights (0.42 g for FC 1 and 0.46 g for FC 2), and pupal weights (1.69 g for FC 1 and 1.80 g for FC 2). FC2 breed showed significant differences in cocoon and shell weights with B × C interactions, highlighting the influence of chemical fertilizers. The study concludes that integrated nutrient management with these combined treatments significantly enhances cocoon, shell, and pupal weights, demonstrating their effectiveness in silkworm rearing.