Development of multiple co-inoculants of different biofertilizers and their interaction with plants

Abstract

The present investigation was undertaken to assess the feasibility and compatibility of different biofertilizers like Rhizobium, Azotobacter, Azospirillum, Pseudomonas and Bacillus as co-cultured multiple inoculant. The microbe-microbe interaction under cultural conditions, in charcoal-based carrier and with pigeonpea and mungbean plants was determined. Under cultural conditions, co-inoculation of Azotobacter, Bacillus, Pseudomonas and Rhizobium resulted in reduced growth of Rhizobium. A co-culture multiple inoculant in sterilized fine wood charcoal powder (200 g) of Azotobacter, Azospirillum, Bacillus and Pseudomonas containing more than 2×108 cells g−1 carrier was possible. However, the number of rhizobia reduced to less than 2×108 cells g−1 carrier, when co-cultured with Rhizobium. Inoculation of pigeonpea and mungbean seeds with multiple co-inoculant produced maximum nodule biomass, plant biomass and total soil N in case of pigeonpea and mungbean hosts. However, no beneficial effect of co-cultured multiple inoculants on nodule occupancy of pigeonpea or mungbean was observed.