Note on the specificity of the rhizobia of crownvetch and sainfoin

Summary Rhizobium of crownvetch (Coronilla varia L.) was tested in test tubes on agar on several legumes and rhizobia from different cross inoculation groups were tested on crownvetch. Effective nodules were only formed on crownvetch after inoculation with crownvetch rhizobium and with two rhizobium strains of sainfoin (Onobrychis vicifólia). Four rhizobium strains from sainfoin nodules and six strains from crownvetch nodules were tested in quartzsand on sainfoin and crownvetch; all strains produced effective nodules on the roots of both species. Rhizobium of crownvetch was present in 32 of 57 soil samples collected in 7 provinces of the Netherlands. This rhizobium is present in most soils in the Netherlands with a pH of 7.8 to 7.0.