Effect of nitrogen and zinc on nodulation, growth and yield of cowpea (Vigna unguiculata)
A pot experiment was conducted to determine the effect of zinc and nitrogen on growth, nodulation pattern and yield of cowpea. The treatments were four levels of nitrogen ( 0 , 10, 20 and 30 kg/ha) and four levels of zinc (0, 5, 10 and 15 kg/ha). Application of various levels of nitrogen significantly increased dry matter production/plant , plant height number of branches/ plant, effective nodules/ plant, total nodule / plant, effective nodules weight /plant, pods/plant , seeds/pod and grain yield. Similarly zinc significantly increased plant height, branches / plant, number of leaves/plant, dry matter /plant, effective nodules weight /plant and grain yield . There was no significant interaction between nitrogen and zinc on grain yield.