Shelf Life of Capsules of The Entomopathogenic Fungi Metarhizium Anisopliae and Beauveria Bassiana

This study assesses the shelf life of capsule formulations of Metarhizium anisopliae (Metchnikoff) Sorokin and Beauveria bassiana (Balsamo) Vuillemin developed using two carrier materials viz., chitosan and talc and active ingredient as spore pellet concentrated to 10¹⁰ ml^-1. The evaluation was done for three months under room temperature and refrigeration. Results revealed that chitosan was more effective (2.51× 10⁷ cfu ml^-1) when compared to talc (1.77× 10⁷ cfu ml^-1) in retaining spore viability in Metarhizium capsules and both the carriers were found to be equally good for formulating Beauveria in capsules with cfu values of 2.11x 10⁷ and 2.02x 10⁷ cfu ml^-1 each. It was also inferred that shelf life of the capsules can be maintained till three months under room temperature with an extension of another two months under refrigeration. The narrow decline in viability observed over three months is negligible as the reduction in number of cfu was not exponential.