Most of the wheat fields in the northern half of the state reached anthesis last week. The remaining fields will reach this critical growth stage during this week. The risk for Fusarium head blight (FHB) has been moderate-to-high over the last 5-7 days on susceptible varieties planted in the northwest corner of the state. However, persistent rainfall, soggy fields, and difficulties scheduling an aerial application, prevented some fields from being sprayed to control scab and vomitoxin at the anthesis/flowering growth stage. If the risk for scab was high a few days ago when your field reached anthesis, but you were unable to apply a recommended fungicide, you can still make an application up to 6 days after anthesis and see good results in terms of scab and vomitoxin control. This is true for Prosaro, Caramba, and Miravis Ace. Applications made 4-6 days after anthesis are effective against scab and vomitoxin and are particularly useful when the weather following anthesis is consistently favorable for scab. In fact, even if the scab risk had decreased over the last few days, a late application would still be warranted, given that conditions were favorable for scab during the week leading up to anthesis.
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