Public interest in sourcing local foods has extended into beverages leading to a rapid expansion of the northeast malting industry. This has provided farmers with new market opportunities and many of these markets are interested in purchasing certified organic barley.  However, all farmers are struggling to produce barley that is not infected with FHB and DON. Hence integrated management strategies are essential for managing yield and quality losses from FHB. The objective of this study was to evaluate the individual and interactive effects of moderately resistant cultivars and application timings of conventional fungicides and an organic copper fungicide on barley yield and the integrated management of Fusarium head blight (FHB) and deoxynivalenol (DON) in Vermont.

 The trial was conducted in Alburgh, Vermont in 2020 on a silt loam soil. The experiment was a completely randomized block design with a split-plot arrangement, with cultivar as the main plot and the fungicide treatments as subplots. The two spring barley varieties were ‘Robust’ (susceptible to FHB) and ‘Genesis’ (moderately resistant to FHB). The fungicide treatments included Caramba®, Miravis Ace, Prosaro SC®, and Champ Ion (an organic fungicide) applied alone or in combination with each other. Fungicides were applied at two timings (Feekes growth stage, FGS 10.1 and/or four days after heading). Treatments were inoculated with a conidial suspension of F. graminearum (40,000 conidia/ml) after the fungicide had dried. An untreated control was sprayed with water.

Yield, test weight, and FHB incidence and severity did not differ statistically by treatment. There were significant differences between treatments for DON concentrations. All treatments and timings, including the control and the Fusarium inoculated plots, had DON concentrations below 1 ppm. Eight treatments had DON concentrations less than that of the uninoculated control (0.19 ppm). These included Miravis Ace at heading, Miravis Ace followed by Caramba, Miravis Ace followed by Prosaro, Miravis Ace at Feekes 10.3, Miravis Ace post heading, Caramba, and Prosaro. The Fusarium inoculated plots had the highest DON concentrations as expected, and they were statistically similar to only the three ChampION treatments and the control.

The DON concentrations in Genesis (0.08 ppm) were significantly lower than the DON concentration in Robust barley (0.22 ppm). When fungicide applications in this trial are compared, the results of this trial suggest that Miravis Ave applied at heading, whether combined with other products or not, was the most successful at reducing DON in comparison to an uninoculated control.