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. Most farmers in New
England have experienced significant crop loss from FHB and some farmers have
already stopped growing barley. At present, few farmers are specifically
selecting varieties for resistance to FHB and even fewer are combining host
resistance with fungicide applications. There has been little to no research
conducted to evaluate organic approved fungicides. In
Vermont during 2022 we observed the disease and yield impact of cultivar susceptibility,
inoculation with Fusarium graminearum,
and treatment with an organic copper fungicide at two timings. The experiment was set up as a completely randomized block design with a split-plot arrangement,
with cultivar as the main plot and the fungicide treatments as subplots,
randomized in four replicated blocks. The two spring barley varieties were ‘Robust’ (susceptible to FHB) and ‘ND Genesis’ (moderately susceptible to FHB). The organic
fungicide ChampIon was applied at heading (Feekes growth stage, FGS 10.1) and
again four days after heading treatment. After the fungicide had dried, plots
were spray-inoculated with a conidial suspension of F. graminearum (40,000 conidia/ ml) to augment the development of
FHB. Grain yield, test weight, and DON
concentrations were measured for each plot. Treatment
means were calculated, subjected to analysis of variance, and separated by
Fisher’s protected LSD test (P = 0.05). The moderately susceptible variety had 56% less
DON compared to the susceptible variety. The fungicide treatments did not
significantly influence DON concentrations compared to the control. The
certified organic treatment of two applications of ChampION did not improve DON
concentrations compared to one application. The barley yields did increase when
ChampIon was applied to the barley compared to the control. For organic producers, these results indicate
that selection of varieties that have moderate susceptibility to FHB should
help growers mitigate some of the risk associated with this disease. The application
of the organic fungicides needs to have continued research to understand if
they can provide control of FHB in the northeastern U.S.