SCAB Fungus spoiling farmers' wheat

Experts predict a widespread outbreak that will include Ohio.
STATE COLLEGE, Pa. (AP) -- It's still early in the season, but Darrell Schlegel can see what's coming in the brown film that is beginning to cover the wheat crops on Ronald Wegman Farm outside Reading.
Inopportune spring rains have brought a reoccurrence of Fusarium head blight, or wheat scab, an infection that withers the grain and can cause vomiting if the grain is eaten.
"I think it's going to cover the whole area. I think it's going to cover everything," Schlegel told The Associated Press recently in a telephone interview. "Without a doubt, I think everybody is going to have it."
Scab is present every year in small amounts, but the disease already is abundant in Virginia, and Erick DeWolf, assistant professor of plant pathology at Pennsylvania State University, said he's expecting a widespread outbreak from the Mid-Atlantic states as far west as Missouri and Arkansas.
"It is pretty bleak," said Don Hershman, extension plant pathologist for the University of Kentucky. "In fact, I just talked with the pathologist at Indiana a little while ago and he said it's bleak there. Illinois isn't good, and Ohio's starting to slide, too."
Scab forms when the Fusarium spores settle in flowering wheat plants. If there's enough moisture combined with the right temperature conditions -- too cold and the spores won't grow, too hot and evaporation steals the moisture -- the infection will set in the head as the grain begins to form.
The fungus robs the grain of nutrients, turning the kernels into pale, pruned ghosts of their potential selves. It also produces a chemical called deoxynivalenol, or vomitoxin, that can sicken people and livestock.
"They call it vomitoxin for a reason," said Erik Stromberg, professor and interim head of plant pathology at Virginia Tech.
How bad it is
Stromberg said he's found evidence of infection in almost every field he's seen. Mena Hautau, the Penn State Extension agent for Berks County, said she saw early signs of scab last week and expects to find more.
Last year's multistate outbreak was expected because of constant rain through much of the spring. But this year's outbreak may take farmers by surprise.
"We actually have had really good growing conditions. The wheat crop was looking excellent, and we didn't have too much moisture," Hershman said. "But it so happened that during the part of the season that it was beginning to flower, there was just enough moisture for the infection to set in."
Some farmers might not even know yet that their crops are infected. The Pennsylvania Agricultural Statistics Service reported Tuesday that as of last week, 76 percent of the state's wheat crop was rated either good or excellent, only 3 percent poor.
But at this time last year, 78 percent of the crop was rated good or excellent. By late July, when farmers were harvesting, that number had dropped to 40 percent, only slightly more than the 39 percent rated poor or very poor.
"Scab has kind of a reputation for doing that. Everything is looking great, and then right before you're ready to harvest, all these blight symptoms show up," DeWolf said. "It can be really disappointing."
In Pennsylvania last year, scab was the main reason yields dropped more than 20 percent, with the state's total production falling almost 30 percent to just 7.1 million bushels.
"We figure last year we probably lost 30 bushels per acre because of scab," Schlegel said. "Right now, we could be at about a third of the crop, and it could get worse unless we get into a real favorable position in terms of the weather."
In the nation's top wheat-producing states on the High Plains, there hasn't been enough rain to make scab a serious problem.
Dewolf, the Penn State professor, said past scab outbreaks haven't had a noticeable affect on consumer prices.