Morpho-physiologicalresponse of three Vigna unguiculata (cowpea) varieties (IT96-610, IT99K-573-1-1 and IT81-994) subjected to sodium chloride (NaCl) stress at concentrations of 0, 50, 100 and 200 mM was investigated, for the purpose of better understanding of salt tolerance of the crop. The study was conducted under control conditions and set out in completely randomized design (CRD) with six replications.Morphological and physiological parameters taken were shoot height, leaves number, area of leaves, plant biomass, carotenoids, chlorophyll pigments, percentage protein, crude protein and ash content. Mean values were compared using Fisher’s L.S.D at 0.05 level of probability.Shoot height, leaves number, area of leaves, shoot, root, leaf, fresh and dry weight of the three varieties of Vigna unguiculata reduced as NaCl concentration increased . Chlorophyll a and b, carotenoids, percentage ash, protein, crude protein also reduced drastically as NaCl concentration increased. The three varieties of Vigna unguiculatas tudied were all responsive to NaCl and the stress was more substantial at higher concentrations (100 and 200 mM).

Keywords: Concentrations, Cowpea, Pigments, Sensitivity, Sodium chloride, Stress