the evaluation of nutrition regimes and rearing periods on biological and economical parameters of silkworm

abstract more than %90 of natural silk in world is produced by means of mulberry silkworm (bombyx mori l.). therefore, it is important that we recognize and collect mulberry varieties which have high quantity and quality leaf performance. for this purpose, an experiment was conducted with five mulberry varieties (kenmochi, kairyonase, ichinose, shinichinose and local varieties) during two seasons(spring and late autumn) in iranian silkworm research center. after recording, obtained biological and economical characters, data (such as larval duration, larval nutrition duration, larval mortality, number of cocoon, best cocoon weight, best cocoon shell weight, shell cocoon percentage, etc.) were analyzed using a complete randomized design (crd) model with factorial arrangement including ten treatments with three replications by means of irristat statistical software. the anova results showed that type of mulberry varieties and rearing seasons have significant effects on silkworm yield (p<0.01). duncun,s new multiple range test (dmrt) results indicated that shinichinose and local varieties are suitable for late autumn rearing, but ichinose and local varieties have the best performance in spring (p<0.05). furthermore, the effect of spring rearing season have the higher values for the most of traits in comparison of autumn season (p<0.01). keyword: mulberry, leaf quality, silkworm, economic characters