Multi-year organic field evaluation of a diverse panel of spring naked barley accessions for feed, food, and malting use

The study objectives were to evaluate a diverse panel of 247 spring naked barley varieties under Irish organic conditions and identify the best-performing lines for multi-use purposes. A trial was conducted on an Irish organic certified field over three years (2019–2021), following a type II modified augmented design (MAD2). The genotypes were evaluated on phenology, agronomy, diseases, threshability, and grain quality. Genotypic effects were significant with heritability above 60% showing good selection opportunities. However, significant genotype-by-year interactions highlighted the importance of trait stability in the selection process. Best performing lines were identified with the Multi-trait Genotype Ideotype Distance Index (MGIDI) using two different ideotypes: MGIDI1 selected 23 lines and was focused on grain quality with yield, lodging resistance, TKW, chemical grain quality and threshability, while MGIDI2 selected 16 lines and comprised additional yield-related traits including early vigor, plant height, green leaf area, diseases infection, phenological characteristics and grain plumpness. The characterization of selection panels highlighted that MGIDI is a valuable tool for increasing genetic gain while preserving genetic diversity. Results showed that yield-related traits influenced yield formation differently across variable climate conditions, and including plant characteristics providing climate resilience may favor long-term genetic gain. Six lines, selected with either MGIDI2 or both MGIDI1 and MGIDI2, exhibited good overall performance across key traits: HB16338, CDC Clear, Purple Prince, 10WA-127.5, Lawina (Myrtle-Creek), and DH140285. Those can be used as parents in future breeding cycles, while other selected lines remain interesting material for crossbreeding.