Abstract
Effect of number of strains of Rhizobium meliloti in an inoculant for alfalfa, cv. Saranac, was studied in relationship to its yield. Combinations of one to six strains were used as inoculants. None of the strains have shown antagonistic activity toward each other in pure culture. Combinations of two strains resulted in the highest yields, indicating synergistic effects. The use of more than two strains in an inoculant resulted in lower yields as compared to a single strain.