Nodules as influenced by Rhizobium inoculation, phosphorus application and their interactions in cowpea [Vigna unguiculata (L.) Walp]

Abstract

Cowpea [Vigna unguiculata (L.) Walp] is an important legume crop with manifold uses. It is used as vegetable, pulse, green manuring and fodder crop in dry and semiarid zones of the world. Potentiality of chemical fertilization for increasing vegetable production has been well established since time immemorial but the major limiting factor in their usage in the high cost. During present period of, energy crisis the scarcity and rising cost of petro-chemical has forced a rethinking for augmenting the biological nitrogen fixation. This would be such to minimize our dependence on fertilizer nitrogen, as the abundant quantities of di-nitrogen can easily be tapped for agricultural purposes through a number of symbiotic bacteria called as Rhizobium.