Now is the time to finalize plans for scab management in Maryland. Wheat will be flowering soon, and conditions are conducive for spore generation. The current forecast includes 30-40% chance of rain through most of this week. If you are in area where wheat comes into flower by the end of this week and rain actually materializes scab risk will jump from low to high and fungicides may be required.
Only Prosaro, Caramba or Proline are recommended for scab suppression. Fungicide applications before heading will not provide disease suppression. Best suppression is achieved when fungicides are applied at early flowering. Applications made up to 5 days after flowering begins are nearly as good as early flowering, and some suppression has been demonstrated with applications 1-3 days before flowering (on fully emerged heads). For those considering ground applications, nozzles angled 30° into the direction of travel provide better coverage of the heads than traditional downward facing nozzles.
Visit the scab forecasting website as your crop approaches flowering for risk assessment to finalize your fungicide decision. The temperatures are currently ideal and the risk level is now dependent on moisture and when the crop flowers.
--Arv Grybauskas, Extension Plant Pathologist, University of Maryland
For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu