Barley is heading across the region, and scab risk is on its way up! If you missed a fungicide application at 50% heading, there’s great news: we have recently revised our recommendations regarding fungicide timing. Work done by researchers in North Carolina found that the best spray timing for protecting winter barley from scab is application six days after 100% heading. With this new guidance we should get better DON reduction in barley than under our previous recommendation which targeted 50% heading. Current labels state that the last stage of application is mid-flower and there is a 30-day harvest restriction. Do not use any of the strobilurins (Quadris, Headline), or strobilurin/triazole (Twinline, Quilt, Stratego) combination products at flowering or later. There is evidence that they may cause an increase in mycotoxin production.

Caramba, Miravis Ace, Prosaro, Prosaro Pro, and Sphaerex all provide very good scab suppression. The Miravis Ace label allows for earlier application than Caramba or Prosaro, but best results are still achieved when application is timed after full heading in barley. Spray nozzles should be angled at 30 deg down from horizontal, toward the grain heads, using forward- and backward-mounted nozzles or nozzles with a two-directional spray, such as Twinjet nozzles. Additionally, a fungicide treatment at heading using any of these products will also give you excellent control of most leaf diseases as well.

--Alyssa A. Collins, Associate Professor, Plant Pathology and Environmental Microbiology, The Pennsylvania State University