Local adaptation and broad performance are synergistic to productivity in modern barley.

Crop populations have enormous impacts on agricultural productivity, yet decelerating gains from breeding suggest that selection strategies need to be reconsidered to better align priorities of breeders and growers. Breeders benefit from releasing broadly adapted varieties that perform acceptably well across their target region; growers benefit from selecting a variety that specializes in their specific location. We tested whether these interests are compatible using 182 entries in a mega‐population of malting barley (spring, two‐row, multi‐environment trial [S2MET] population; Hordeum vulgare L.), which was grown across the northern United States. We assessed the strength of genetic–environment interactions (G×E), quantified local adaptation benefits, and tested whether local adaptation and genetic yield potential were correlated. Breeding programs favored broad adaptation (p < 0.001). Still, 63% of entries (114) were among the top 10%, best performing at some locations, and among the worst 10% at others. Some of the best overall entries were specialists, performing especially well in their home locations, and in general, genetic potential and local specialization were positively correlated (p < 0.001). These results suggest that breeding for local performance and broad performance are mutually supporting goals. Releasing broadly excellent, locally exceptional varieties may accelerate genetic gain to meet projected global agricultural demand. Core Ideas: Releasing locally adapted varieties can accelerate genetic gain at the cost of breeding efficiency.We test whether locally and broadly adapted strategies are synergistic in the modern barley mega‐population, spring, two‐row, multi‐environment trial malting barley population (S2MET).Specialist lines tended to yield higher overall, indicating a synergy between these strategies.Broad adaptation at the population level indicated that breeders favored generalist lines.Releasing broadly excellent, locally exceptional varieties is feasible and better aligns breeder and grower needs. [ABSTRACT FROM AUTHOR]