BIOPROSPECTING THE POTENTIAL OF PLANT GROWTH PROMOTING RHIZOBACTERIA-ASSISTED CULTIVATION PRACTICES TO REDEFINE THE PRODUCTIVITY OF PEPPERMINT (MENTHA PIPERITA L.)

Abstract

Aim To evaluate the potential of the plant growth-promoting rhizobacterium (PGPR) Agrobacterium radiobacter, isolated from the rhizosphere of peppermint genotype MPS-3637, in enhancing biomass, essential oil yield, and menthol content of peppermint (Mentha piperita L.) variety CIM-Suras under field conditions. Methods and results Agrobacterium radiobacter was aseptically isolated from the rhizospheric soil of peppermint genotype MPS-3637 and applied to suckers of peppermint variety CIM-Suras under field conditions, either alone or in combination with vermicompost (@ 5 kg ha⁻¹). Compared with untreated control plants, inoculation with A. radiobacter alone increased biomass by 1.5-fold, resulting in an 80.70% increase in essential oil content and a 13.78% increase in menthol content. The combined application of A. radiobacter and vermicompost further enhanced biomass by 2.5-fold, increased essential oil content by 54.39%, and improved menthol content by 11.08% over the control. Conclusion The application of Agrobacterium radiobacter, either alone or in combination with vermicompost, significantly enhanced biomass production, essential oil yield, and menthol content in peppermint variety CIM-Suras. These findings demonstrate the potential of this PGPR as a sustainable and environmentally friendly approach for improving peppermint productivity and profitability while reducing reliance on conventional agricultural inputs. Impact statement Plant growth-promoting rhizobacteria offer a sustainable alternative to conventional inputs, but their effectiveness depends on the selection of compatible host–microbe combinations. This study demonstrates that Agrobacterium radiobacter can substantially enhance peppermint biomass, essential oil yield, and menthol content under field conditions. These findings support the development of targeted microbial bioinoculants for medicinal and aromatic crops, contributing to sustainable peppermint cultivation, improved farmer profitability, and reduced reliance on chemical inputs.