Pod yield stability and adaptation of groundnut (Arachis hypogaea L.) genotypes evaluated in multi-environmental trials in Zimbabwe

Abstract

Twenty-five groundnut genotypes were evaluated to identify the types of Genotype-Environment-Interaction (GEI) for pod yield. Genotypes were evaluated under multi-environmental yield trial conducted in 2013/14 season at five environments. The objectives of the experiment were to: identify genotypes with high pod yield stability, to identify genotypes with specific/wide adaptation, identify groundnut mega environments and identify an ideal environment. ANOVA was performed using GenStat Version 14. The results of the ANOVA indicate that there was GEI. The environments (E) and the interaction between the genotype and the environment were significant. GGE biplot analysis for yield data was the performed. The partitioning of GGE through GGE bi-plot analysis indicated that principal coordinate 1 and 2 (PC1 and PC2) explained 59.22 and 20.17% of GGE sum of squares, respectively, explaining 79.39% of the total variation. This large percentage variability of GGE (79.39%) accounted by the bi-plot indicates that there was complex GEI. The environment and genotype explained 58.8 and 6.1% respectively of the total treatment variance, while the genotype by environment interaction accounted for 35.1%, indicating that the environment had huge influence on genotype performance. The results revealed the existence of mega-environments, most ideal environment and genotypes with specific and others with wide adaptation. The results indicate that certain genotypes may be released for commercial production in specific environments based on their performance. Key words: Groundnut, genotypes, pod-yield, multi-environmental trial, genotype x environment interaction, discriminating, representative.