Genotype-by-Location Two-Way Data Analysis

Analysis of a genotype‐by‐location two‐way table for a key trait has been the most important topic of variety trial data analysis and has commonly been referred to as genotype‐by‐environment data analysis or multi‐environment trial (MET) data analysis. Although the focus of variety trial data analysis is on economically important traits, traits with high heritability, with or without important economic values, are useful for detecting human errors. Genotype‐by‐location data analysis includes three main aspects: mega‐environment analysis, test location evaluation, and genotype evaluation. All these aspects can be graphically addressed using GGE biplot analysis, supplemented with numerical outputs. The use of different biplot forms in mega‐environment analysis, test location evaluation, and genotype evaluation are described in this chapter. Summary statistics of grain yield at individual locations are presented in the chapter.