Gary Bergstrom, Extension Plant Pathologist, Cornell University
The risk of Fusarium head blight and DON contamination is moderate to severe for winter wheat flowering in much of New York at this time. General rains are expected again on Sunday. The triazole products Caramba and Prosaro are the most effective fungicides for suppression of FHB and DON contamination when applied at flowering (emergence of anthers on heads). There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB suppression can be expected. A flowering application of triazole fungicide should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rusts, and fungal leaf blotches in the upper canopy based on scouting of individual fields. Each has been observed in certain fields. Consider especially the regional risk of stripe rust as it is beginning to be observed in diverse areas of western New York and we continue to have conducive conditions for stripe rust infection. Fungicide products containing strobilurins should not be applied to headed wheat or barley as they may result in increased levels of DON in grain. Check the Fusarium Risk Assessment Tool (http://www.wheatscab.psu.edu/) and your local weather forecast frequently as your winter wheat crop approaches heading and flowering.
Winter malting barley fields are at grain filling stages now and beyond the timing for foliar fungicide application. Spring malting barley fields are mostly at tillering stages now.
Integrated management of wheat and malting barley diseases will be discussed at Cornell’s Small Grains Management Field Day at the Musgrave Research Farm on June 8 (http://events.cornell.edu/event/small_grains_management_field_day_4909 ).
