Fusarium Head Blight Risk Update, April 10, 2019

— Written By Lindsey Thiessen

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

As of April 10, 2019, wheat is still 1 to 6 weeks from flowering, with many fields late in development due to late planting. In the coastal plain, barley that was planted on time has headed or will soon head. Currently, FHB risk is low in all the wheat- and barley-growing areas of NC. The forecast holds little rain, which means risk should remain low for the next 10-14 days. There is no need to apply fungicides for FHB when risk is low at wheat flowering or barley heading.

To monitor FHB risk in your area, utilize the Fusarium Risk Assessment Tool.