Fusarium Head Blight Risk Update, April 15, 2019
Fusarium Head Blight
Fusarium Head Blight (FHB), also known as scab, is caused by several Fusarium spp., particularly F. graminearum in the U.S. The fungus overwinters in soil or in crop stubble from previous crops (ie corn, wheat, other grasses). Spores from overwintering fungal structures are released during periods of wet weather, and risk for FHB infection occurs during wheat flowering or barley heading. FHB is a concern for grain growers because of the production of mycotoxins, like deoxynivalenol (DON).
Disease is managed through the use of moderately resistant varieties and fungicides timed to periods of high risk. The Fusarium Risk Assessment Tool provides a prediction of risk for wheat producing regions in the U.S. Fungicide efficacy for FHB and other common diseases can be found from North Central Regional Committee on Management of Small Grain Diseases (NCERA-184) For FHB, the most effective fungicides are Prosaro, Caramba, Proline, and Miravis Ace. Fungicides containing strobilurins may increase DON, and those fungicides should not be used after flag leaf in case of an FHB epidemic.
More information on FHB and symptoms can be found at the Small Grains Extension portal.
Current risk estimates are based on plants that are currently flowering. Regions of medium to high risk for FHB infections in southeast NC (Pender, Onslow, and adjacent counties) are predicted for this week, as of April 15, 2019. Late-planted wheat fields are likely not near flowering yet, but those fields planted on time may be flowering. Fungicides are less effective when applied prior to flowering, and should be applied at early flowering.
To monitor FHB risk in your area, utilize the Fusarium Risk Assessment Tool.