Title: Competitive interaction between non-nodulating and nodulating strains for nodulation of cowpea (Vigna unguiculata)
Abstract: We have examined the effect of a non-nodulating mutant (JRW3-SmD) on the nodulation ability of cowpea rhizobia (Bradyrhizobium sp.) strains JRW3 and IRC256. Nodulation of cowpea (Vigna unguiculata) by a nodulating Rhizobium strain is suppressed by the presence of a non-nodulating mutant. The msgnitude of suppression for nodule formation by nodulating strains varied between 40% and 80% depending on the strain and the time of inoculation.