Nodulation of Dry Beans by Commercial and Indigenous Strains of Rhizobium phaseoli1

Abstract

AbstractSuccessful nodulation and seed yield increase of dry bean (Phuseolus vulgarisL.) is not often observed after inoculation with Rhizobium phaseoliin the bean production region of North Dakota and Minnesota. A 2‐yr field study was conducted to assess nodulation by indigenous soil strains and commercial strains 127K12b, 127K44, and 127K81‐3 of R. phaseoliin the dry bean cultivars ‘Fleetwood’, ‘Pindak’, ‘UI‐114’, and ‘Upland’. Inoculation with the commercial strains, compared with uninoculated controls, did not increase seed yield; however, nodule number and nodule fresh weight were influenced. Strain 127K12b produced more nodules, more total nodule tissue, and larger nodules than other commercial or indigenous strains. The cultivar UI‐114 had more nodules, total nodule tissue, and larger nodules regardless of inoculum sources. The effect of individual inoculum strains did not vary between years, but was cultivar‐specific for nodule characteristics. Inoculation with commercial strains resulted in significantly greater nodule numbers, nodule tissue, and larger nodules relative to indigenous soil strains.