JACKSON, Tenn. — Widespread rain in the region last weekend, and storms forecast later this week, could dampen efforts to control fusarium head blight (FHB), or wheat scab, the region’s most economically important wheat disease.
Most wheat in Tennessee had already been sprayed before rain moved through. "There are very few (Tennessee) fields left that producers are deciding whether or not to put out a fungicide for head scab," said Heather Young-Kelly, University of Tennessee plant pathologist.
"Research has shown the most effective timing for controlling FHB and mycotoxin levels is at flowering, but applications made five to six days after initial bloom can also provide a benefit in reducing FHB and mycotoxin levels."
Wheat disease updates issued by Illinois and Tennessee plant pathologists last week emphasize an integrated approach to managing wheat scab. This approach combines variety selection, well-timed spraying, crop scouting and monitoring local conditions.
But weather can still trump the best FHB management efforts. Carl Bradley, University of Illinois plant pathologist, said wheat scab wreaked havoc on southern Illinois growers in 2014. "Thinking about how to manage this disease cannot occur too early," said Bradley.
Stripe rust is another disease concern this year in Illinois, he said. Fungicide applications for FHB can also help control stripe rust. "In light of the current rain moving through, forecasted rain for later this week and the observation of stripe rust in some varieties in southern Illinois, I would encourage growers to strongly consider applying a fungicide to help manage fusarium head blight and other leaf diseases," he said.
He was to outline the integrated approach during a presentation at the UK Wheat Field Day in Princeton, on May 12.
Wheat scab is the most economically important wheat disease in the region as it forms vomitoxin (deoxynivalenol, or DOV) in the grain. Producers can be heavily docked for the presence of DOV when selling grain. "Pairing fungicide with a resistant variety will provide the best protection and both the FHB forecast model, along with your local forecast and information about your own field, will better guide fungicide application decisions," said Young-Kelly.
The FHB forecast model may be accessed at the Fusarium Head Blight Prediction Center website, at www.wheatscab.psu.edu which provides state-by-state FHB updates and outlook.
