Performance Stability of Cotton Cultivars Across Major Regions in US Cotton Belt.

Analysis of genotype (G) × environment (E) interactions and its influence on performance of cotton (Gossypium hirsutum L.) cultivars across environments can help cotton breeders improve performance stability of cultivars across environments. The objectives of this study were to analyze performance of cotton cultivars across major regions of the US Cotton Belt and determine stability of genotypes in order to identify highly stable genotypes with high performance in lint yield and fiber quality across these highly variable environments. Data were obtained from Regional High Quality Tests in National Cotton Variety Trials conducted during 2005 and 2009. Performance stability of cultivars across environments was analyzed using GGE biplot software. Although genotype × location and genotype × year interactions were highly significant, strong genotypic effects for lint yield and strength relative to these interactions were observed consistently in trials during all test years. Environments of test locations for lint yield were grouped using GGE biplot in order to identify possible megaenvironments. There were no megaenvironments identified which could group all test locations consistently across years. This result indicated highly unpredictable environmental factors across locations and years in the Cotton Belt. Thus, selection for superior genotypes with wide adaptation to environments across locations was recommended.