20615

Impact of Individual and Co-Administrations of Juvenile Hormone Analogue and Phytoecdysteroid on the Crop Management and Performance of Silkworm, Bombyx mori L.

Sashindran Nair K نويسنده , Kariappa B.K نويسنده , Kamble C.K نويسنده

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Juvenile Hormone Analogues (JHAs) are administered to 5th instar silkworm for improving the cocoon yield and phytoecdysteroid (PE) for hastening the larval maturation events and synchronizing cocoon spinning activities. As individually both these techniques are accepted and quite popular now, doubts persist about their co-administration in the absence of a planned study. This study addresses this concern. JHA and PE were applied to separate and same batches of 5th instar silkworm to ascertain the response in terms of management criteria and crop performance. In three different treatment procedures adopted, T1 was applied with JHA alone at the 48 h of 5th instar, T2 was applied with JHA at 48 hand PE at the onset of larval maturation and T3 with PE alone. To served as untreated control. The popular bivoltine silkworm hybrid, CSR2xCSR4 and multixbivoltine hybrid, PMxCSR2 were used for this study. The results of two trials showed that JHA treatment alone enhances the cocoon yield quite handsomely with a prolongation in the 5th instar period at least by 24 h. T2 not only enhances cocoon yield but brings in the advantages of PE administration. The prolongation is limited to 12 h. PE alone hastens and synchronizes larval maturation and reduces the larval period by about 18 h.

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