Provided they reliably predict row plot performance, hill plots should be useful for doubled haploid recurrent selection in malting barley (Hordeum vulgare L.). The primary objective of this research was to compare hill and row plot expression of agronomic and malting quality traits in an array of elite spring habit barley germplasm grown under irrigated conditions. A supporting objective was to identify an appropriate seeding rate for hill plot evaluation. Eight-replicate hill plots at four seeding rates (10, 20, 30, and 40 seeds per hill) were compared with adjacent four-replicate row plots in each of three environments. Genotype and genotype × environment interactions were significant for most agronomic traits in both plot types. Significant, linear genotype responses to hill plot seeding rates were observed for most agronomic traits. Seeding rate had no consistent effect on the expression of malting quality. The percentage of lines in common in the two plot types at 25 and 50% selection intensities was the most useful comparison statistic and indicated hill plot selection should be effective for most agronomic and malting quality traits. Although yield heritability estimates were consistently high in both hill and row plots, there was little relationship between trait expression in the two plot types. Differential tillering in response to hill plot competition is likely responsible. A seeding rate of 10 seeds per hill should be appropriate in preliminary screening for traits amenable to hill plot selection in irrigated spring habit malting barley.Key words: Hordeum vulgare L., malting quality, breeding methods, barley
Identification of promising sources of hulless barley (Hordeum vulgare L.) for important quality traits
