Abstract

Twenty-eight (28) cowpea genotypes were evaluated in a multi-location trial across the Guinea Savannah agro-ecological zone of Ghana from June to October 2007. The three locations which were among the major cowpea producing areas in northern Ghana included Damongo, Yendi and Nyankpala. The objectives of the study were to: (1) assess cowpea grain yield and its selection criteria for maize-cowpea intercropping condition (2) determine whether cowpea lines selected under sole-crop conditions are productive under cowpea-maize additive series intercropping system. Even though there was significant genotype x location interaction effect for grain yield, the interaction did not complicate selection strategy. Selection for intercropping systems may be done under sole cropping due to similar heritability values, non-significance of genotype x cropping system interaction and lower error associated with evaluations under sole cropping compared to intercropping system. SARC 14-88, SARC 14-110, SARC 14-208, SARC 14-78, IT 95K-193-2 and IT 97K-499-35 were identified as the most intercrop-adapted genotypes. Such promising grain yielding genotypes could be used for grain yield improvement using intercrop susceptibility index (ISI), earliness to flower as well as grain yield under sole cropping system as selection criteria for maize-cowpea additive series intercropping system. Keywords: genotype, cropping system, genotype by environment interaction, savannah zones