Relationship between moisture tolerance versus yield and yield components in Cowpea

The experiment was carried out to exploit the broad spectra of genetic variability in cowpea germplasm for improvement of high moisture tolerance. Twenty-five germplasm lines of diverse genteic background with three local cultivars were involved in the evaluation over two cropping seasons (early and late) under rainfall conditions across two locations in 2006. The experiments were conducted in the Teaching and Research Farm, Ambrose Alli University, Ekpoma (Lat. 6o 08′ E and Long. 6o 42′ N) in a rain forest–savanna transition area with mean annual rainfall of 1200mm to 1556mm; and at Benin–Owena River Basin Development Authority, Obayantor, near Benin (Lat. 6o 09′ 24″and Long. 5o 35′ 27″ E) in the humid rainforest area with mean annual rainfall of 2032mm to 2540mm. RCBD with three replications was used. Significant negative relationship (r) existed between moisture tolerance and pods per plant, seeds per pod and grain yield which indicated that as severity of moisture level in the soil increased with time, susceptibility level of the germplasm also increased with a consequent reduction in the number of pods per plant, number of seeds per pod and grain yield. Seeds per pod and 100–seed weight were recognized as the common attributes for grain yield and selection be done based on these traits for improvement of cowpea for high moisture stress.