Submitted to: American Society of Brewing Chemists Newsletter
Publication Type: Abstract only
Publication Acceptance Date: 5/6/2007
Publication Date: 6/17/2007
Citation: Ullrich, S.E., Jitkov, V.A., Budde, A.D., Schmitt, M., Wise, M.L. 2007. How can varieties and rain-fed production environments affect malting quality in spring barley?. American Society of Brewing Chemists Newsletter. 67(2)P50. Interpretive Summary:
Technical Abstract: Rain-fed barley production environments can be highly variable across a region and across years. Almost all malting barley production in Washington State is under rain-fed conditions. The industry has noticed that in some cases malt beta-glucan levels and other malting quality parameters have been unacceptable in barley raised in eastern Washington under rain-fed conditions. We therefore, undertook a three-year (2003–2005) study to measure barley (BBG) and malt/wort (MBG) beta-glucan levels, as well as, other malting quality parameters in six spring barley varieties (2-row AC Metcalfe, Harrington, Farmington, Radiant and 6-row Legacy and Morex) at four variety test locations. The mean annual precipitation range at these four locations (2003–2005) was about 380–500 mm (15–20 in.), which represents the precipitation range for realistic malting barley production in eastern Washington. All nine parameters evaluated were affected by variety (V), location (L) and year (Y). No variety x environment (V x E) interactions were detected for malt extract percentage (ME), barley protein percentage (BP), soluble/wort protein percentage (SP), soluble/total protein ratio (S/T), and barley beta-glucan percentage. VxE interactions were detected for kernel weight (KW), VxL and VxY; for diastatic power (DP), VxL, VxY, and VxLxY; for alpha-amylase activity (AA), VxL and VxY; and for malt beta-glucan content, VxL, VxY, and VxLxY. Whereas, temperature means varied for the four test locations for the growing season (Apr.–Aug.; 15–18 C) and for the Jul.–Aug. grain fi lling period (20–23 C), they did not vary from year to year. Precipitation did vary from year to year for crop year (Sept.–Aug.) and for growing season (Apr.–Aug.). Crop year precipitation was highest in 2004 at all but one location and lowest in 2005 at all locations. Growing season precipitation was also highest in 2004 but lowest in 2003 at all locations. The year effect on the malting quality parameters was almost exclusively due to variation in precipitation. There were no clear common trends for variety performance for all parameters measured across locations or years. However, there were predictable trends for ME, KW, BP, SP, S/T, and DP, but not for AA, BBG, and MBG. No test location was clearly superior for producing highest malting quality across all parameters. Among the premium malting varieties in the study, AC Metcalfe had slightly higher overall quality compared to Harrington, but Legacy and Morex were essentially equal in quality. The lower quality Farmington and Radiant were clearly distinguished from the premium varieties. ME and MBG were most dramatically and negatively affected in 2005, the driest year. Overall, only rain-fed production conditions in the driest years would cause concern for malting quality acceptability.