Effect of phosphorus and zinc nutrition on growth and yield of fodder cowpea

An experiment consisting of four phosphorus levels (0, 40, 60 and 80 kg/ha P2O5) and five zinc levels (0, 10, 20, 30 and 40 kg/ha ZnSO4) was laid out in randomized block design in factorial mode to find out the effect on yield and quality of fodder cowpea [Vigna Unguiculata (L.)Walp.]. Growth parameters viz. plant height, number of leaves, number of branches, leaf length, leaf width and leaf stem ratio were improved with the application of 60 kg/ha P2O5 and 20 kg/ha ZnSO4. Application of 60 kg/ha phosphorus recorded 27.64 t/ha yield, which was 7.50 and 55.6 % higher than 40 kg/ha and no phosphorus application, respectively. Application of zinc in the form of ZnSO4 @ 20 kg/ha increased significantly the green fodder yield (25.89 t/ha). Interaction effect of phosphorus and zinc application was found significant with respect to fodder, dry matter yield and nutrient uptake. Yield, phosphorus and zinc uptake in cowpea fodder were showing declining trend at combination of application rate more than 60 kg/ha P2O5 and 20 kg/ha ZnSO4.