Though Upper Midwest small grains were still being planted as of early May, some southern winter wheat and barley crops were already reaching a critical growing period in terms of possible infection by fusarium graminearum, the fungus that causes fusarium head blight (or head scab). A spot check among states found both favorable and unfavorable conditions.
In some parts of eastern North Carolina, “more fusarium head blight is being observed than at any time since 2003,” said Christina Cowger, small grains pathologist with U.S. Department of Agriculture-Agricultural Research Service at North Carolina State University. “In the state wheat variety trial in Beaufort County (northeastern part of the state), scab incidences of 1 to 25 percent were recorded” during the second week in May. Some of that area’s commercial fields showed scab incidence levels of up to 10 percent, she said.
“Scab incidence appears to be dependent on variety resistance and crop growth stage during the last week of April, when rain occurred in much of the eastern part of the state,” Cowger said. The USDA and NCSU put out an extension alert to county agents and crop consultants during that period to be on the lookout for scab.
Virginia also received rains during head emergence this spring, and forecast maps predicted the state was at risk for FHB infection. “There is a lot of variation in heading-flowering date this year, even within a region,” said Wade Thomason, Extension grains specialist with Virginia Tech. “Some producers planted and some waited; some waited quite a while for it to dry out. I suspect we will see quite a bit of variation in FHB among fields because of this.”
Carl Griffey concurred with Thomason. “Wheat in Virginia, depending on location, is just heading, flowering or finished flowering,” the Virginia Tech small grains breeder said on May 7. As of that date, it was still too early to get a good handle on the full extent of FHB development and severity, he added.
A few hundred miles to the southwest, Arkansas appeared “to have dodged FHB this year,” according to Gene Milus, plant pathologist with the University of Arkansas. As of early May, he had not seen any symptoms of scab in the state’s wheat field or heard any reports of infection. “(But) there is still time for FHB to develop, depending on the weather,” Milus said.
Louisiana State University wheat and oat breeder Stephen Harrison said some scab incidence in the state this year, "but not much." Incidences occurred mainly in the rice region of southwestern Louisiana, Harrison said, with a few additional reports of FHB in the northeastern part of the state.
Jerry Johnson of the University of Georgia said he had not heard of any significant scab problems this spring in Georgia.
This article was submitted by the U.S. Wheat and Barley Scab Initiative.