Abstract

Freddy Dramani Pele, Asamoah Yeboah, Marcel Shatta Buari and E. J. Kof

Drought stress represents one of the most important abiotic constraints limiting cowpea production in the arid and semi-arid zones of Africa. Since drought susceptibility index (S) represents drought tolerance at whole plant level regardless of drought tolerance mechanism in operation, a potted experiment was conducted in a plant house (August to October 2011) to identify morpho-physiological parameters and develop drought susceptibility index for selecting drought tolerant cowpea varieties. These parameters included relative water content (RWC), plant height (PHT), number of leaves per plant (NL), stem diameter (SD) and root dry mass (RDM). A 2×6 factorial arranged in completely randomized design with three replications was used. The results showed highly significant effects among the cowpea genotypes, as regards to the water regime treatments and their interaction for all the morpho-physiological parameters used in this study (RWC, PHT, NL, SD and RDM). Significant positive relationship was found between NL and RDM with r = 0.97, p<0.001. With relatively better performance under water-stressed condition, as indicated by the drought susceptibility index, variety Dan illa was the best genotype recommended to be used as source for drought tolerance in a cowpea breeding programme.