Mass production of entomopathogenic fungi Purpureocillium lilacinum PL1 as a biopesticide for the management of Amrasca devastans (Hemiptera: Cicadellidae) in okra plantation

Abstract Background Effective management strategies are crucial in minimizing the adverse consequences associated with the leafhopper, Amrasca devastans (Dist.) (Hemiptera: Cicadellidae). Economic limitations to entomopathogenic fungi production present a substantial challenge, particularly in developing countries. This study aimed to investigate a cost-effective solid-state fermentation (SSF) for large-scale production of Purpureocillium lilacinum PL1 conidia to manage A. devastans infestations in okra cultivation. Results Rice and maize were demonstrated as highly suitable substrates for producing conidia densities of over 2 × 10 10 conidia g −1 . Furthermore, the influence of agricultural phytosanitary agents on the growth rates of P. lilacinum PL1 was evaluated. Certain pesticides were ineffective on the expansion of P. lilacinum PL1 colonies, while fungicides exhibited complete inhibition. The laboratory investigation revealed that 1 × 10 7 conidia ml −1 of P. lilacinum PL1 exhibited a success rate of 88.66% in decreasing the population of A. devastans nymphs in vitro. Furthermore, field investigations carried out in okra plantations demonstrated that the utilization of P. lilacinum PL1 at the concentration of 1 × 10 7 conidia ml −1 of resulted in a significant reduction of the pest nymph population by 72.87% subsequent to the 2 applications. Conclusion In conclusion, the cost-effective mass production of P. lilacinum PL1 conidia through SSF presents a promising solution for managing A. devastans infestations in okra farming, particularly in economically challenged regions.