Adaptability Performances of Cowpea [Vigna Unguiculata (L.) Walp] Genotypes in Ethiopia

Abstract

Sixteen cowpea genotypes were tested at seven environments in experiment laid out in 4 x 4 triple lattice designs during 2016/17 cropping season. The combined analysis of variance over environments showed significant differences among genotypes, environments, and significant effect of GEI on grain yield, days to flowering, days to maturity, plant height and pods per plants. Analysis of varaiance for grain yield from AMMI model,  indicated the contribution of genotype, environment and GEI  accounted for about 63.3%, 5.3%, and 29.7% of the total sum of squares, respectively. The result indicated environment was contributed much to the observed variations suggested the need to test cowpea genotypes at diverse environments. Two genotypes, IT-99K-1060a (1398.8 kg/ha) and 86D-378 (1377.1 kg/ha) had first and second highest yield, identified as responsive to both environments but more to favorable environments suggested the need to further test to develop as varieties. Other two genotypes, 95K-1095-4A and 93K-619-1, identified as highly responsive to environments suggested to consider the genotypes as candidate varieties where they performed best.

Keywords: Additive Main Effects and Multiplicative Interaction, Triple lattice and GIE.