From Gary Bergstrom – Extension Plant Pathologist – Cornell University
Nearly all winter wheat in New York is now past the stage for application of fungicides. The focus now shifts to spring cereals, particularly spring malting barley, many fields of which will reach full head emergence this week. The triazole products Caramba and Prosaro are the most effective fungicides for suppression of FHB and deoxynivalenol (DON) toxin contamination when applied at full head emergence in barley (anthers begin to appear on barley before heads emerge from the boot) or at at wheat flowering (emergence of anthers on heads). There is an application window of approximately 6 days from the beginning of flowering in which reasonable FHB suppression can be expected. Fungicide products containing strobilurins should not be applied to headed wheat or barley as they may result in increased levels of DON in grain. Triazole applications at flowering should provide adequate protection against early developing rust, powdery mildew, and fungal leaf blotches on flag leaves. Predicted risk of FHB is currently high for spring cereals flowering over the next few days in many areas of New York. Check the Fusarium Risk Assessment Tool (http://www.wheatscab.psu.edu/) and your local weather forecast frequently.
