Winter malting barley in New York is ahead in development compared to a year ago. Some barley heads are already emerging from the boot and this is a critical time to consider a fungicide application. The Fusarium Risk Assessment Map (www.wheatscab.psu.edu) today indicates a low risk of Fusarium head blight (FHB) for most areas of New York, primarily based on lower temperatures. It is important within the Risk Tool to select an appropriate level of resistance for your variety. Calculated risk increases dramatically in very susceptible compared to susceptible varieties; varieties currently being grown in NYS typically range from susceptible to moderately susceptible. Rain showers are in local forecasts over the next week; duration of leaf/head wetness is more important for FHB development than is the amount of precipitation. 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. Fungicide products containing QoI (FRAC Group 11) fungicides should not be applied to headed wheat or barley as they may result in increased levels of DON in grain.

Winter wheat is generally a week or more behind in development from winter barley planted on the same fall date. Winter wheat in New York varies from stem elongation to flag leaf visible stages. We should reach the critical fungicide application window for winter wheat over the next few weeks. Wheat varieties being grown in New York vary from moderately susceptible to moderately resistant. 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. Powdery mildew has been observed in mid-canopy in some fields. There is an application window of a pproximately 7 days from the beginning of flowering in which reasonable FHB and DON suppression can be expected. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently as your winter wheat crop approaches heading and flowering.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University