MALT QUALITY IMPROVEMENT IN NORTH-AMERICAN 6-ROWED BARLEY CULTIVARS SINCE 1910

Twenty-one historical North American six-rowed malting cultivars, with dates of release from 1910 to 1990, were grown at the North Dakota Ag ricultural Experiment Station in Fargo during 1990, 1991, and 1992. Gr ain from these samples was micromalted, and the resultant samples were analyzed for 13 quality traits. The results of analysis were used to evaluate improvements in quality over time, specifically to document c ases where barley breeding programs have been most successful in impro ving the malt quality of North American six-rowed barley. Significant differences between cultivars were observed for all malt quality trait s evaluated, but improvements over time were not observed for all trai ts. Consistent improvements were found for 1,000-kernel weight, kernel plumpness, grain protein, soluble protein, ratio of soluble to total protein, malt extract, fine-coarse malt extract difference, alpha-amyl ase activity, and diastatic power (DP). The greatest gains were made i n traits for which barley breeders select. These include kernel plumpn ess, malt extract, wort protein, alpha-amylase activity, and DP. Impro vements over time were not observed for wort viscosity and barley and malt beta-glucan contents.