Productivity and resilience based indices for identification of water stress resilient genotypes in cowpea (Vigna unguiculata L.)

This paper reports the usefulness of a new method for identification of productive and resilient cowpea genotypes. The new indices called as Yield Susceptibility Score Index (YSSI) and Yield Production Score Index (YPSI) are based on a scoring scales, offer simple and easy visualization and identification of genotypes that possess resilience, productivity, both or none. A set of 40 cowpea genotypes was evaluated and stress indices were combined in terms of new indices based on a combination of stress susceptibility index, the stress tolerance index, the mean productivity index and the tolerance index, which have been previously used either in isolation or together for understanding water stress adaptation. This new selection method could help breeders and researchers by defining clear and strong criteria to identify genotypes with high resilience and high productivity and provide a clear visualization of contrasts in terms of grain yield production under stress. The approach is highly useful in initial evaluation of large germplasm sets for identification of resilient and productive cowpea genotypes.