PRODUCTION, VIRULENCE, AND VIABILITY OF Beauveria bassiana (Bals.) Vuill. CONIDIA OBTAINED BY FERMENTATION OF AMARANTH STUBBLE

Abstract

Entomopathogenic fungi biological formulations require viable concentrations of infective units (conidia) with high virulence. These are mainly produced by solid-state cultivation of agro-industrial residues with high C/N ratios as substrates, such as amaranth stubble (Amaranthus hypochondriacus L.), which is discarded in the fields due to its lack of postharvest utility and thus becomes a source of contamination. Therefore, its use can reduce production costs when compared to common substrates such as rice (Oryza sativa). The objective of this work was to compare the effect of amaranth stubble on the production, virulence, and viability of Beauveria bassiana (Bals.) Vuill. (Hypocreales: Cordycipitaceae) conidia produced by solid-state cultivation to those produced using rice as a substrate. The results showed that the yield of B. bassiana conidia produced with rice was 15 higher than that produced with amaranth stubble. However, there were no significant differences in the virulence and viability of conidia produced by both substrates. Therefore, the use of amaranth stubble is an economical alternative to produce B. bassiana conidia compared to common substrates like rice.