Tricia McMillan (1), Marta Izydorczyk (1), John O’Donovan (2), Shawn Parsons (1), Debby Shaluk (1), Kelly Turkington (2); (1) Canadian Grain Commission, , Canada; (2) Agriculture and Agri-Food Canada, Canada

Malt and Grains

Fungicide applications can benefit cereal growers by increasing yield and kernel weight, especially when the risk of various fungal diseases is high. Application of fungicides may also increase in popularity given the expansion of Fusarium sp. to most of the barley-producing prairie regions. Although rarely used in Canada, plant growth regulator (PGR) application may help to optimize yield and quality of malting barley by mitigating the effects of lodging. However, little information exists on the impact of PGR application, especially in conjunction with fungicide application. The objectives of this study were to assess the individual and interactive effects of head-emergence fungicide and PGR applications on barley kernel characteristics and malting quality of AC Metcalfe grown in seven environments across the Canadian prairies. The experimental design was a factorial combination with (+) and without (–) PGR and fungicide applications. The PGR Ethrel was applied at 1,000 mL/ha after early flag leaf emergence to swollen boot stage. The fungicide Prosaro was applied at 324 mL/acre as a preventative spray at heading. Barley quality was assessed by measuring kernel weight, kernel plumpness, protein content and germination energy. Barley grown in five environments was selected for malting (Phoenix micromalting system) and subsequent malt quality analysis. Germination energy was not significantly affected by either application. Protein content was significantly lower (P < 0.05) for (+) PGR samples compared to (–) PGR samples, but it was not significantly affected by the additional application of fungicide. The application of fungicide significantly (P < 0.05) increased kernel weight and plumpness, while the application of PGR had an opposite effect. In general, when both fungicide and PGR were applied, kernel weight and plumpness were slightly higher compared to the control (– PGR, – fungicide), which may have contributed to the slightly lower steep-out moistures and higher extract levels observed for these samples. PGR application significantly (P < 0.05) increased malt friability and was likely a secondary result due to the lower protein content. Although not statistically significant, fungicide application appeared to have a slight negative impact on the starch-degrading enzymes, but the levels of enzymes were still within the range expected for AC Metcalfe. Although fungicide application did not have a significant impact on malt friability, a significant effect (P < 0.05) on wort beta-glucan and viscosity was observed; the level of wort beta-glucans and wort viscosity were higher for fungicide-treated barley compared to the control samples. Additional malt quality testing and microbial load data will help to increase our understanding of the effects of fungicide and PGR application on malt quality.

Tricia McMillan works as a chemist at the Grain Research Laboratory of the Canadian Grain Commission in Winnipeg, MB. She graduated from the University of Manitoba with a B.S. degree in food science and went on to obtain her M.S. degree from the Department of Human Nutritional Sciences. She joined the Canadian Grain Commission in 2001, where for the last 12 years she has worked as a chemist in the Barley Program. The research of this program focuses on identifying, characterizing, and quantifying constituents, as well as genetic, agronomic, and environmental factors, affecting the quality and performance of barley during malting and brewing processes.