Field Assessment of Cowpea Genotypes for Drought Tolerance

Abstract

Drought is one the most damageable constraints to crop production impacting negatively food security. The potential of cowpea to address food security is well established. However, drought due to limited rainfall is causing important yield losses. This study was conducted to assess cowpea genotypes for variability to drought tolerance at Saria Research Station, Burkina Faso, in 2012. Fifty cowpea genotypes were grown under drought stressed and non-stressed conditions. Plants grown under non-stressed conditions were watered regularly from sowing to maturity while those in the stressed conditions were watered from sowing to 50% flower bud initiation and thereafter, irrigation was withheld till harvest. Selection indices and principal component biplot were used to differentiate genotypes. A wide genotypic variability among the tested germplasm was found.

In the Biplot displayed, genotypes were grouped into four categories according to their drought tolerance and yielding ability as indicated below: high yielding-drought tolerant (group A), high yielding-drought susceptible (group B), and low yielding-drought tolerant (group C), and low yielding-drought susceptible (group D). The stress tolerance index was the best criterion for assessing genotypes for variability to drought tolerance because it enabled the identification of high yielding and drought tolerant genotypes.