Effect of Different Carriers on Shelf Life of Bradyrhizobium japonicum

During present investigations shelf life of Bradyrhizobium was studied by using different carriers viz., glycerol lignite, polyvinylpyrrolidone (PVP), ethylene diamine tetra-acetic acid (EDTA), gum arabica mixed with 10, 15, 20, 25, 30 and 35 ml Bradyrhizobium broth combination. The viability count was taken by serial dilution method at 30, 60 and 90 days after inoculation. Shelf life studies indicated significant differences in rhizobial colonies in all testedcarriers. Among all tested combinations of carriers, population of Bradyrhizobium was found high at low concentration of carrier materials i.e. 10ml (glycerol, PVP, gum arabica and EDTA)with 90 ml Bradyrhizobium broth at 30, 60 and 90 days after inoculation. The increase in concentration of carrier materials was found lower in population of Bradyrhizobium but more population than control. Comparative analysis of different carriers showed that among the all carrier tested the population of Bradyrhizobium was found higher in PVP carrier material at all combinations at 30, 60 and 90 days after inoculation.