Effect of mineral and Bio-Nitrogen fertilizers on cowpea growth and yield

This work was carried out during the two summer seasons of 2009 and 2010 at El-Khatara Experimental Farm, Fac. Agric., Zagazig university to study the effect of cultivars, Rhizobium and nitrogen fertilization on growth, seed yield and seed quality of cowpea under sandy soil conditions. Cream -7 cv. in the 1st season and Dokki-331 in the 2nd season gave the highest values of dry weight of leaves and total dry weight/ plant, also, Cream -7 and Dokki-331 cvs. recorded the maximum values of number and weight of pods/plant, number of seeds/ plant , yield of seeds/ plant and per fed. in both seasons. Inoculation of cowpea seeds with 200 g/fed. Rhizobium increased significantly number of pods, average pod weight, number of seeds/ plant as well as yield of seeds/ plant and per feddan. Dry weight of leaves , total dry weight as well as number of seeds/ plant and total yield of seeds/ plant and per fed. were significantly increased with increasing nitrogen rates up to 60 kg N/ fed. in both seasons. Fertilization of cvs. Cream-7 and Dokki-331 with Rhizobium at 200 g/fed. and mineral at 45 kg N/fed. or 60 kg N/fed. increased dry weight of leaves and total dry weight/ plant as well as seed yield per plant and per fed. in both seasons.