Compatibility of Metarhizium anisopliae and Heterorhabditis indica in different formulations

Abstract

Study on "Compatibility and efficacy of Metarhizium anisopliae and Heterorhabditis indica in different formulations against white grubs in sugarcane." is carried out in 2024-2025, at the RCSM College of Agriculture in Kolhapur. The main objective was to assess the compatibility of M. anisopliae and H. indica in different formulations as well as their effectiveness against white grub in pot culture. In the present study, sodium alginate gel observed as the most suitable and effective carrier, supporting a mean CFU of 2.78 × 10⁷ g⁻¹ for M. anisopliae and achieving 95.44% survival of H. indica. Comparatively lower viability and survival rates were recorded in other carriers, such as talc and cocopeat. Pot culture studies showed a dose- and time-dependent increase in grub mortality, with the highest mortality (80.00%) recorded at 21 days after treatment (DAT) with T5 (10 ml L⁻¹). T4 (8 ml L⁻¹) also showed comparable results (77.78%). Mean mortality followed a similar trend: T5 (65.26%), T4 (61.48%), and T3 (51.85%), while the untreated control recorded no mortality. The findings suggest a complementary interaction between the EPN (early action) and the fungus (sustained infection), with alginate gel encapsulation enhancing persistence and controlled release. Overall, the alginate gel formulation proved to be most effective for maintaining microbial viability and achieving significant white grub management, indicating strong potential for field application.