Evaluation of exotic cowpea genotypes for grain yields in autumn, winter and summer seasons

Cowpea (Vigna unguiculata) as leguminous crop was being needed by the people to supplement their diet in form of protein. Our local cultivars did not provide the continuous yields throughout the year; therefore the current research is required to find out genotypes that produce grain all round the year. The experiment was conducted at the Gezira University Farm, Wad Medani, Sudan, during autumn and winter,(July and November respectively) of 2005, and summer ( April) of 2006. The experiment was arranged in a randomized complete block design with three replications. Planting was done following recommended practice with spacing of 18cm× 30cm. The experiment was conducted to assess the potential of 18 exotic cowpea genotypes for high grain yield. The traits measured were number of pods/ plant, number of seeds / pod 100 seed weight and grain yield during seasons. In individual analysis of variance for seasons, significant differences were observed among genotypes for all characters studied except, number of pods/ plant, number of seeds / pod and grain yield during autumn season. This experiment suggests that the highest grain yielders were IT98K-412-13, IT99K-1060 and IT98K-131-2 during autumn. IT98K-428-3 and IT98K-412-8 during winter, and IT98K-1399 and IT98K-412-13 during summer, but throughout the year the genotypes IT98K-412-13 and IT98K-1399 were recommended with range of 1.4 to 2.1 t/ha. This could be attributed to their genetic differences in, number of pods/plants and number of seeds/pod. For dual purpose (grain and dry forage) it is suggested to grow the genotypes IT89KD-288, IT95K-52-34 and IT98K-412-13 throughout the year.