Effect of nitrogen, phosphorus and seed inoculation on cowpea (Vigna unguiculata)

A field experiment was conducted during the summer seasons of 1992 and 1993 at Lakhaoti to study the effect of nitrogen. phosphorus and seed inoculation with Rhizobium culture on cowpea [Vigna unguiculata (L.) Walp.]. Application of 20 kg N/ha or seed inoculation with Rhizobium significantly improved the seed yield over control. Combined application of N + seed inoculation further induced significant increase in seed yield over their individual application. Successive increase in phosphorus up to 90 kg P2O5/ha significantly increased the seed yield.