Cumulative Effects of N P K and Mg Salts with Plant Growth Hormones on Growth and Some Nitrogen Metabolizing Enzyme and Soluble Protein in Rhizobium sp.

The symbiont Rhizobium sp. was isolated from root nodules of Vigna radiata cultivated in the field. The isolate was sub-cultured in Yeast Extract Mannitol Broth (YEM) that was supplemented with optimum concentration of N, P, K and Mg salts and three plant growth hormones (IAA, GA and kinetin) and their various combinations. The growth behaviour, nitrate reductase (NR) activity, nitrite reductase (NiR) activity, nitrogenase (N-ase) activity and soluble protein were found to be enhanced with treatment of N, P, K and Mg salts and plant growth regulators (IAA, GA and kinetin) and their various combinations at different hours (24 to 120h) after inoculation.