An inoculant Rhizobium strain for improved establishment and growth of hexaploid Caucasian clover (Trifolium ambiguum)

Abstract Strains of Rhizobium leguminosarum bv. trifolii present in New Zealand soils are ineffective on Caucasian clover (Trifolium ambiguum) and inoculation with an effective strain of rhizobia is essential for nodulation. However, problems have been encountered with nodulation of oversown Caucasian clover and this study was conducted to determine whether nodulation could be improved by the use of an improved strain of rhizobia. Five strains of rhizobia were compared with a re‐isolate (ICC 105) of the recommended New Zealand commercial inoculant strain (ICMP4073b) for their effect on the establishment of oversown hexaploid Caucasian clover in Canterbury and Otago, South Island, New Zealand. When strains were incorporated in peat inoculant and used to inoculate seed in a commercial pelleting process, one strain (ICC 148) increased the percentage of seedlings nodulated over that obtained with ICC105, from 23% to 49%. In a further evaluation of these two strains, seed was inoculated and lime‐coated in the ...