FHB Update from OH, 05/20/19

In northern Ohio, most of the wheat fields are between Feekes growth stages 9 (full flag leaf emergence) and 10 (boot), with the odd early-planted field or field planted with an early- maturing variety beginning to head-out. In southern Ohio, fields are between Feekes 10 and early flowering (Feekes 10.5.1). For those fields of wheat at flowering and fields of barley heading-out today (May 20), the risk for head scab is moderate to low. However, persistent rainfall and warmer temperatures over the next few days will likely cause the risk to increase as more fields reach anthesis later this week and early next week. But remember, scab risk is also linked to crop development; fields of wheat that are not yet at the flowering growth stage and field of barley that at not yet at the heading growth stage are at low risk for head scab. Continue to keep your eyes on crop development, the weather, and the forecasting system, and be prepared to apply a fungicide if warm, wet conditions coincide with flowering and early grain fill. Prosaro, Caramba, and Miravis Ace are the most effective fungicides for head scab and vomitoxin management, and you will have a 4-6-day window from the day the crop reaches the critical growth stage (heading for barley and flowering for wheat) to make an application. Do remember to stay away from the strobilurin fungicides when the risk for scab is high, as this group of fungicides has been linked to higher grain contamination with vomitoxin.

--Pierce Paul, Extension Plant Pathologist, Ohio State University

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