INFLUENCE OF GIBBERELLIC ACID AND TRIACONTANOL ON SOME ECONOMIC CHARACTERS OF SILKWORM BOMBYX MORI

Effect of gibberellic acid (GA3), triacontanol and combination of them, on some economic characters of silkworm Bombyx mori were investigated. For this experiment, a hybrid bivoltine race of silkworm (Psix NB18) was fed with mulberry leaves sprayed with GA3, triacontanol and a mixture of the two from fourth instar onwards. The plant growth regulators enhanced the larval growth rate, cocoon weight and yield as well as the fecundity of silkworms. Triacontanol appeared to be most effective, which significantly increased the silk ratio (SR%), effective rate of rearing (ERR%) and average filament length of the cocoons. The use of plant growth regulators, as a supplement of diet with mulberry leaves in view of economic feasibility was discussed.