RHIZOBIUM STRAIN SELECTION FOR FABABEANS

Abstract

Strains of Rhizobium leguminosarum from a number of geographical origins were tested for N-fixing effectiveness on fababeans (Vicia faba L.). Initial screening in the greenhouse was followed by field testing of the best strains on soils low and high in nitrate-N in 1976. Strains F1 and F15 from Morocco produced significantly higher fixation rates than other effective strains during pod-filling in the low nitrate soil. Percent N in the seed and N yields were also highest with these strains. Strains F1 and F15 were tested again in 1978 with three other effective strains against three fababean cultivars. There were no strain × cultivar interactions, but N-fixation during pod-filling and seed N % were higher with F1 and F15. The value of testing strains through to plant maturity is illustrated by this result. F1 also produced the highest N yield but differences among strains were not significant. Differences in N yield among cultivars were significant in 1978.