Multi-potent rhizobacteria enhance banana growth and reduce chemical fertilizer input

Introduction The present investigation isolated efficient potassium-solubilizing bacteria (KSB) from the banana rhizosphere and, along with nitrogen- and phosphorus-transforming strains from TNAU, evaluated their impact on banana growth, yield, and fertilizer reduction. Methods Solid and liquid-based formulations using the nitrogen-fixing bacterium Azospirillum brasilense Sp7 ( A. b Sp7), phosphorus-solubilizing bacterium Bacillus megaterium Pb1 ( B. m Pb1), and the newly isolated potassium-solubilizing bacteria Agrobacterium pusense ( A. p . KRBKKM1) and Bacillus paralicheniformis ( B. p KRBKKM2) were prepared and used for inoculation in the field experiment. HPLC profiling of KSBs showed that A. p . KRBKKM1 produced propionic acid, and B. p KRBKKM2 produced butyric and propionic acids. Results Among the two formulations tested, the liquid formulation had a significantly greater influence on the yield and yield-attributing traits than the solid-based ones. Treatments consisted of 75% NPK chemical fertilizer + 2 mL A. b Sp7 + 2 mL B. m Pb1, along with 1 mL A. p . KRBKKMI and 1 mL B. p KRBKKM2 (T10-30.65 t ha −1 ), and 75% NPK + 2 mL A. b Sp7 + 2 mL B. m Pb1, along with 2 mL A. p . KRBKKMI and 2 mL B. p KRBKKM2 (T11-30.82 t ha −1 ) significant impacted the banana yield parameters. Discussion Principal component analysis revealed that treatments T10 and T11 positively correlated with yield-related parameters. Pearson correlation analysis revealed that crop yield was positively correlated with the bunch weight ( r = 1.00***), fruit weight ( r = 0.84**), and number of fingers per bunch ( r = 0.76**), in both the solid and liquid formulations. In conclusion, the present investigation demonstrated a 25% reduction in chemical inputs when using NPK biofertilizers and contribute to increased agricultural productivity.