Selection of cowpea genotypes in hydroponics, pots, and field for drought tolerance

The evaluation of cowpea (Vigna unguiculata [L.] Walp.) for drought tolerance in the field is slow, laborious, and provides variable results. The objectives of the study were to assess the differences in the growth of cowpea genotypes in hydroponics, and to determine whether such differences could be associated with drought tolerance in pots and field. Four cowpea genotypes varying in drought tolerance were evaluated for differences in height, collar diameter, leaf area, shoot and root biomass, root-shoot ratio, and root volume in hydroponics. On the basis of these results, selection of cowpea for vigorous growth under well-watered conditions could be conducted by means of hydroponics; however, rapid selection of cowpea for drought tolerance could not be made by this technique.