In field trials near Hyderabad in 1977-81 and in Karnataka in 1981, 4 Spanish-type, 1 Valencia and 5 Virginia type groundnut cv. were inoculated with 1 or 10 strains of Rhizobium sp. at sowing in soil previously sown to groundnuts. Pod yields of cv. Robut 33-1 were consistently increased by inoculation with strain NC 92, the increases ranging from 18 to 34% in Hyderabad and reaching 40% of the yield of non-inoculated plants in Karnataka. Inoculation with the pure strain NC 92 gave higher yields than a mixture of NC 92 with other strains of Rhizobium sp.ADDITIONAL ABSTRACT:A total of 9 varieties were tested in 1977-1981 with ten strains at two localities. Robut 33-1 inoculated with strain NC92 had significantly higher pod yields (up to 40% higher) than it had without inoculation. Other variety X strain interactions were not observe