Four strains of Rhizobium leguminosarum bv. trifolii were screened for their use in inoculants for red clover (Trifolium pratense) in the Soil Microbiology Sector, Department of Soils, University of Rio Grande do Sul, Porto Alegre, Brazil, from January 1994 to March 1995. In greenhouse experiments, all four strains presented similar efficiency in nitrogen fixation. However, when mixed strains were used, the strain SEMIA 222 was more effective in nodule formation. In a yeast manitol sucrose medium, growth rate was higher […]