Response of cowpea (Vigna unguiculata) to AM and bradyrhizobium in a heavy and light textured soil

Abstract

A field experiment with cowpea (Vigna unguiculata (L.) Walp.) cv. Ife Brown was carried out in 1995 in a heavy textured loamy sand Iwo series soil and in 1996 in a light textured soil of the same series to determine its response to single or dual inoculation with arbuscular mycorrhiza (AM) fungus, Glomus mosseae and a mixture of Bradyrrhizobium strains IRj 2184A and IRc 256. Single or dual inoculation increased the plant height, nodule number and weight, dry matter accumulation of shoot, percent nitrogen(N) and phosphorus (P) in plant tissue, and the percent N, derived from atmosphere when compared with ninoculated control in the 2 years. Grain yield was enhanced by 20% due to dual inoculation in 1995 and only 1% in 1996. The rate and intensity of AM infection were significantly improved by inoculation.