Genotype × Environment Interactions and Stability in Organic Wheat

Abstract

Optimizing wheat (Triticum aestivum L.) genotypes for organic production can improve lagging yields worldwide. New genetic improvement programs, such as for organic wheat, require an understanding of genotype × environment interactions. Over 6 yr at 10 organically managed sites in the northeastern and north‐central United States, we assessed genotype × environment interactions for yield, test weight, protein, and falling number. We used an additive main effects and multiplicative interactions model to identify mega‐environments with distinct variety performance throughout the northeastern United States. Results indicate that organic wheat breeding and variety testing programs should decentralize selection into multiple locations. After determining the impact of changes in genotype performance across years, we assessed genotypes for stability in yield, test weight, protein, and falling number. Breeding for stability should be prioritized for the northeastern and north‐central United States, due to the large contribution of genotype × year interactions.