Plant growth promoting Rhizobacteria (PGPR) for suppression of root-feeding insect larvae and soil-borne plant pathogens

Globally, root-feeding insect pests and soil-borne fungal infections significantly reduce yields, yet managing both at the same time is still difficult. Plant growth-promoting rhizobacteria (PGPR) that can inhibit both biotic. In this study the synthesis of indole-3-acetic acid (IAA) and the activity of 1-aminocyclopropane-1-carboxylate (ACC) deaminase were assessed in ten bacterial strains that were isolated from the rhizospheres of healthy agricultural plants in Odisha, India. IAA (26.3 µg/mL) and ACC deaminase activity (0.78 µmol α-ketobutyrate mg^-1 h^-1) were highest in isolate RS-09. In cowpea greenhouse pot tests, RS-09 dramatically lowered root damage from white grub larvae by 38.9% and disease severity indices of Fusarium oxysporum and Rhizoctonia solani by more than 40%. In comparison to stressed controls, PGPR inoculation increased shoot and root biomass by 35-40% under combined pathogen-insect load. These results emphasize the potential of RS-09 for integrated pest and disease management.