Rhizobacteria isolated under field first strategy improved chickpea growth and productivity

Plant growth promoting rhizobacteria (PGPR) are being used as bioinoculant for enhancing plant growth and productivity. But their failure to survive and influence plant growth is a major hurdle because of rhizospheric rejection and crop-specific nature which can be overcome by field first strategy, as a revision of the existing protocol. The research is aimed to explore the beneficial impacts of rhizobacteria on crop plants at field-scale. The PGPR were, therefore, isolated from the standing healthy plants. The isolates were directly applied in the field using seed bacterization for cultivation of the crop and the evaluation of vegetative parameters. Simultaneously, the isolates were evaluated for plant growth promoting (PGP) traits in the laboratory. Thereafter, selection of field—adapted rhizobacteria was done on the basis of in-field and in vitro plant growth promotion. The potential rhizobacteria were used for yield improvement of chickpea (Cicer arietinum) in a second field trial. In this study, a consortium of two taxonomically distinct rhizobacteria Bacillus altitudinis MRN-16 and Pseudomonas chlororaphis MRN-52 showed promising plant growth promotion during in-field selection; in spite of PGP attributes, Pseudomonas korensis MRN-58 failed to improve crop yield. On the other hand, both the isolates showed effective inhibition of radial mycelial growth of Fusarium oxysporum, causing wilt of chickpea. The consortium of MRN-16 and MRN-52 enhanced the production of chickpea in terms of grain yield (9.86%) and biological yield (3.49%) with harvest index (6.45%). Thus, ‘field-first strategy’ proved more significant scheme for the recruitment of beneficial bacteria with much certainty and suitability in order to achieve growth and yield improvement of chickpea.