From Gary Bergstrom, Extension Plant Pathologist, Cornell University
Most of the winter wheat and barley in New York State initiated flowering over the past 10 days, under low forecast risk of Fusarium head blight (FHB). The triazole products Caramba and Prosaro are the most effective fungicides for suppression of FHB and deoxynivalenol (DON) toxin contamination when applied at wheat flowering (emergence of anthers on heads) or at full head emergence in barley (anthers begin to appear on barley before heads emerge from the boot). A flowering application of triazole fungicide should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rust, and fungal leaf blotches in the upper canopy based on scouting of individual fields. There is an application window of approximately 5-6 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. The risk of FHB epidemics forecast by the model remains low to moderate for crops flowering today. But I urge growers to check the Fusarium Risk Assessment Tool (http://www.wheatscab.psu.edu/) and your local weather forecast frequently if your crop has just begun or is about to begin flowering. We will consider the risk of FHB infection of spring wheat and barley in New York starting next week.
