FHB Update from MD, 05/19/14

The scab forecasting site shows moderate risk for the eastern shore of Maryland and low risk west of the bay. I suspect the risk level will decline on the shore because of the cool dry air mass that settled in after the heavy rain last week. However, if rain develops as forecast on Tuesday night through Wednesday then the risk level will increase again for all regions. Currently a lot of wheat is in flower or is beginning to flower. Fungicide application should be considered for wheat that has begun to flower or is just a day or two past. Wheat that has not fully headed should not be sprayed and should be reassessed after Wednesday.

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.

--Arv Grybauskas, Extension Plant Pathologist, University of Maryland

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu