FHB Update from WI, 06/10/19

Most varieties of winter wheat are now at anthesis (flowering) in southern and south-central Wisconsin. Now is the time to manage Fusarium head blight (FHB or scab) and vomitoxin. The Fusarium head blight Risk Model (http://www.wheatscab.psu.edu) has tapered off in the last week in terms of predicted risk of FHB. However, there are still areas of moderate to high risk in the primary wheat growing region of the state. Weather conditions are projected to turn excessively wet over the next 3-5 days, thus I predict risk will rise again. FHB was severe in many wheat fields in 2018, and considering the weather this season and reports of FHB to our south, I anticipate 2019 being problematic. Fungicide products of choice to control FHB in Wisconsin include Caramba, Prosaro, and Miravis Ace. Multiple years of data in Wisconsin suggest that the best application window for any of these products begins at the start of anthesis until 5-7 days after the start of anthesis. Applying fungicide before anthesis or more than 7-10 days after anthesis will result in poor performance against vomitoxin accumulation. Information pertaining to recent fungicide studies on winter wheat in Wisconsin, can be found at this link: https://badgercropdoc.com/wp-content/uploads/sites/5/2018/12/2018-Fungic... and scrolling to page 12. Other reports can be found here: https://badgercropdoc.com/research-summaries/.

--Damon Smith, Extension Plant Pathologist, University of Wisconsin-Madison

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org