Variation in the performance of contrasting maturity class of cowpea cultivars (Vigna unguiculata L. Walp) in the derived Savanna
Three field trials (2009, 2010 and 2011) were established at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (7°38′N, 3°88′E; 450 m asl). The trials aimed to evaluate the performance of cowpea cultivars of contrasting maturity class in the derived savanna. Four short and seven medium duration (local check inclusive) cowpea cultivars were sown in a randomised complete block design, replicated three times. Across the years cowpea cv. IT98K-573-2-1 (short duration) had the significantly (p < 0.05) highest seed yield (2486 kg ha-1), an observation that could be attributed to its pod yield (3651 kg ha-1), stand count (73.1) and earliness (49.22 days). Cowpea cv. IFE-98-12 (medium duration) produced significantly low pod weight (1826 kg ha-1), with the least shelling weight (613 kg ha-1) and stand count (44.87) across the years. Three clusters of cowpea cultivars were identified in Principal Component Analysis biplot. They were identified based on their superior performance on seed yield, duration of development and dry fodder weight for short duration, medium duration and local check, respectively. It is concluded that these attributes could form the basis of their use and crop improvement programme in the derived savanna.
Keywords: Earliness, medium duration, shelling weight, short duration