Much of the winter malting barley in New York reached full head emergence in the past several days when the Fusarium Risk Assessment Map (www.wheatscab.psu.edu) indicated low risk of Fusarium head blight (FHB) across the state. Maximal suppression of FHB and grain contamination by deoxynivalenol (DON) mycotoxin results when fully emerged heads of winter malting barley are sprayed with DMI (FRAC Group 3) containing fungicides Caramba, Prosaro, or Miravis Ace (latter includes FRAC Group 7 fungicide). A heads-emerged spray with these fungicides also protects upper leaves against fungal leaf blotches, powdery mildew, and rusts. Foliar sprays of any of these three products up to seven days after head emergence may still result in significant FHB and DON suppression. We are currently observing low levels of scald and powdery mildew in winter barley.

Much of the winter wheat in New York is at boot stage and is expected to initiate flowering during the first week in June. The DMI (FRAC Group 3) containing fungicides Caramba, Prosaro, or Miravis Ace (latter includes a FRAC Group 7 fungicide) are the most effective fungicides for suppression of FHB and DON contamination when applied at flowering (emergence of yellow anthers on heads). A flowering application of these fungicide products 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. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB and DON suppression can be expected. Severe powdery mildew has been observed in some mildew-susceptible varieties. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently as your winter wheat crop approache s heading and flowering.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University