Combined effects of rhizo-competitive rhizosphere and non-rhizosphere Bacillus in plant growth promotion and yield improvement of Eleusine coracana (Ragi).

This study emphasizes the beneficial role of rhizo-competitive Bacillus spp. isolated from rhizospheric and non-rhizospheric soil in plant growth promotion and yield improvement via nitrogen fixation and biocontrol of Sclerotium rolfsii causing foot rot disease in Eleusine coracana (Ragi). The selection of potent rhizobacteria was based on plant-growth-promoting attributes using Venn set diagram and Bonitur scale. Bacillus pumilus MSTA8 and Bacillus amyloliquefaciens MSTD26 were selected because they were effective in root colonization, rhizosphere competence, and biofilm formation using root exudates of E. coracana L. rich with carbohydrates, proteins, and amino acids. The relative chemotaxis index of the isolates expressed the invasive behavior of the rhizosphere. During pot and field trials, the consortium of the rhizobacteria in a vermiculite carrier increased the grain yield by 37.87%, with a significant harvest index of 16.45. Soil analysis after the field trial revealed soil reclamation potentials to manage soil nutrition and fertility. Both indexes ensured crop protection and production in eco-safe ways and herald commercialization of Bacillus bio-inoculant for improvement in crop production and disease management of E. coracana.