Indiscriminate and over application of agrochemicals in agricultural practices is one of the major global threats that has resulted in reduced soil fertility and poor crop productivity. The ACC deaminase positive and phosphate solubilizing bacterial strain ES3 isolated from chilli rhizosphere was identified as Bacillus pumilus using 16S rRNA sequence analysis. The ACC deaminase positive B. pumilus and Mesorhizobium ciceri were used singly and/or as mixture to assess their impact on chickpea grown under pots and field soils treated with or without fertilizers in order to find a companionable bacterial consortium for raising chickpea production. Bacillus pumilus strain ES3 and M. ciceri strain RG5 showed variable plant growth promoting activities. The co-culture of B. pumilus and M. ciceri showed the highest growth promotory effects and profoundly enhanced the biological and chemical characteristics of chickpeas. The biological, chemical and seed attributes were further amplified when bacterized chickpea was grown in pots/field soils treated with 30 Kg urea/ha or 80 Kg diammonium phosphate/ha. The results suggests that B. pumilus and M. ciceri, exhibiting multiple plant growth regulating activities can be applied as an eco-friendly and growth catalyzing microbial-inoculant to foster the production of chickpea in fields while reducing the use of fertilizers.

Keywords: ACC deaminase, Plant growth promoting rhizobacteria, Bacillus pumilus, Mesorhizobium ciceri