Effect of intergenotypic competition on yield assessment at different spacings in cowpea (Vigna unguiculata L. Walp)

Study on the effect of intergenotypic competition at different spacings in cowpea (Vigna unguiculata L. Walp) revealed that the magnitude of competition effects depended not only on genotypes but also on spacings. All characters except pod length and seeds per pod were significantly influenced by the competition. Average competition effect was, in general, smaller and non-significant at wider spacings. An inverse relationship was found between competition effect and spacing i.e., the competition effect increased as the distance between plants decreased. Estimation of the average competition effects and expected bias in nonbordered single-row plots at different spacings suggests wider spacing as an efficient way of curtailing competition bias since most of the characters were free from competition bias at 20-and 40-cm spacings.