Abstract
Four Rhizobium strains known to produce differences of up to 100 per cent in the vegetative dry weight of a test cowpea cultivar were used as separate micro symbionts in combination with four semi-erect cowpea cultivars with contrasting growth habits. The nodulated plants were grown in pots under controlled temperate condition in a plastic house during U.K. summer months and cultivar-strain interactions with respect to vegetative and reproductive performance were recorded. Significant differences between and within cultivar were recorded for almost all components of vegetative growth and seed yield. Although a single Rhizobium strain was not clearly superior for all cultivar tested, those isolated from tropical soil gave generally greater seed yield than the exotic strains tested. The significance of cultivar-strain election in cowpea breeding strategies is discussed.
