Winter wheat in South Dakota ranges from flag leaf to flowering as of the week of June 10. Wheat that is heading or flowering is most prone to Fusarium head blight (FHB or scab) development provided the weather conditions are conducive, since the source of inoculum is plenty in the environment. Based on the FHB prediction tool, the risk for FHB is currently low in South Dakota with exception of few scattered areas along the Missouri River in Lyman, Brule, Buffalo and Hughes Counties where the risk is mainly moderate. The decision to apply a fungicide to manage FHB should be based on the current risk and also on the weather forecast in the next several days if wheat is at heading or flowering. High humidity or rainfall in the forest can change the risk for FHB from low to high in a short time. If a susceptible or moderately susceptible cultivar was planted, a fungicide is advised for areas in moderate or high risk for FHB. The best fungicide timing for FHB management is at flowering (50% of the plants are flowering).
Follow this link for fungicides effective against FHB shorturl.at/hlDU5
–Emmanuel Byamukama, Extension Plant Pathologist , South Dakota 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