Manitoba Agriculture Wheat Fusarium Head Blight Risk Model
Holly Derksen – Field Pathologist, Crop Industry Development
Anne Kirk – Cereal Specialist, Crop Industry Development
Rejean Picard and Earl Bargen – Farm Production Extension
To increase understanding of resulting Fusarium Head Blight (FHB) infection based on the current model.
Dry conditions in 2017 were not conducive for infection by Fusarium head blight. Yield differences observed between varieties were as expected and influence from disease was minimal. Comparisons between varieties may also be made to consider whether growing a resistant variety and not applying a fungicide provides equal or better protection than growing a less resistant variety and applying a fungicide. When looking at disease levels (FHB Index, FDK, DON), the moderately resistant variety, AAC Brandon, sprayed with a fungicide resulted in comparable disease levels to the resistant variety (with or without a fungicide). In some cases, even using a moderately susceptible variety (Muchmore) and using a fungicide resulted in disease levels similar to that of the resistant variety (with or without a fungicide).
Recent research has indicated that delaying a fungicide application for Fusarium head blight suppression in wheat might be as effective as or more effective than the recommended timing when conditions are not conducive for infection at the recommended timing. There were high levels of Fusarium head blight in 2016 across the Canadian prairies. In Manitoba, many fields received a fungicide application at the recommended timing of early anthesis, but Fusarium remained a major downgrading factor. It is hypothesized that some of these infections occurred later in anthesis and therefore may have caused an increase in DON content without a resulting increase in disease symptoms or fusarium damaged kernels (FDK).