Phosphorus Level Affects Brown Blotch Disease, Development and Yield of Cowpea

Application of Phosphorus in adequate concentrations could directly or indirectly reduce disease incidence and severity of cowpea brown blotch and improve the forage and grain yield. A field experiment was conducted to investigate the effects of level of phosphorus application on Brown Blotch disease of cowpea (Vigna unguiculata [L.] Walp), caused by Colletotrichum capsici during 2003, 2004 and 2005 planting seasons. Application of phosphorus was at 30, 60, 90 and 120 kg ha 1 of P2O5. As P level increased numbers of petioles, pods, nodules, seed/pod, leaf area and yield significantly increased. Disease incidence and severity of Brown Blotch were significantly reduced at 90 and 120 kg ha 1 of P2O5 was not affected irrespective of the method of application. Application method did not affect yield. Reduction in brown blotch disease at higher levels of P was recorded.