Wheat is at the stage where growers should consider applying a fungicide where conditions are conducive to Fusarium head blight or leaf diseases. Currently, wheat is heading in many southern Michigan fields and, within a week, fields will likely head in the northcentral parts of the state. Once wheat is headed (the base of the head has cleared the base of the flag leaf), it usually takes 2 or 3 days for the first flowers (anthers) to appear. Fungicide applications for head scab should be made 2 to 5 days later. At this point, most or nearly all the heads will have at least one or more anthers. The recommended fungicides include Prosaro and Caramba. Risk has dissipated significantly over the past few days according to this forecast model. However, continue to check this site as there is marked differences in weather patterns across the state and rainfall is predicted for the next couple of days. Suppressing leaf diseases, in addition to head scab, has been a significant financial justification for the use of fungicides at this timing. Although these diseases have been slow to develop this season, wheat should be scouted regularly as foliar diseases can develop rapidly under favorable conditions.
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