Published on 05/13/96

Virus Taking Bite Out of Georgia Wheat

Georgia wheat farmers figure to get some of the best prices ever for this year's crop. That makes their losses to a viral disease even harder to take.

"We can find barley yellow dwarf virus in just about every wheat field across the state at some level," said Randy Hudson, an entomologist with the University of Georgia Extension Service. "Fortunately, not all the fields have the same level of damage."

Hudson and Dewey Lee, an Extension feed grains agronomist, figure losses will approach $8 million, depending on the weather in the final days before harvest, which starts in late May.

Georgia's wheat harvest is divided fairly evenly between the part milled for flour and the grain exported as livestock feed.

Farmers' reduced yields won't affect the price of your flour or bread because Georgia grows such a tiny part of the world market. But they'll take a bite out of an otherwise healthy boost to the state's rural economy.

Hudson said earliest-planted wheat in east-central Georgia shows the most dramatic symptoms of the disease. But it's in other areas, too.

"We've seen losses of more than 50 percent in specific fields in east Georgia," he said.

Other fields may show disease symptoms but not lose much of their wheat.

Boyd Padgett, an Extension plant pathologist, said he's seen the disease in nearly every wheat variety grown in Georgia. "Some may be less susceptible, but that's not immunity," he said.

Farmers planted wheat on about 400,000 acres in more than two- thirds of Georgia's counties this year. Extension economist George Shumaker said low world grain supplies have driven up prices for wheat and other small grains.

Farmers have seen prices in the $6-per-bushel range for the July 1996 crop. That's nearly double last year's $3.50 wheat.

This virus relies on aphids to travel from plant to plant and from one field to another. Partly because they're so small, aphids are hard to control.

Hudson is working with David Buntin, a research entomologist, to control aphids in Georgia and the Southeast. But barring aphid control, he said, farmers can't do anything to prevent infection or help infected plants.

"A virus causes barley yellow dwarf," he said. Plant viruses act like most viruses in humans. You can't prevent them or cure them.

"Farmers need to know this is out there," Padgett said. "But going out and spraying fungicides for barley yellow dwarf is a waste of time and money."

The disease slows the flow of nutrients from leaves to the forming grain head. As a result, less grain is harvested. Hudson said the plant makes lower-quality grain, too.

Even with the disease problem, this year has been very good for wheat farmers. "The crop condition is good," Shumaker said. "And farmers who have taken advantage of the high prices are looking at a very profitable year."

So what can farmers do?

Very little besides preparing for next year. "Once they're aware of the problem," Hudson said, "they need to manage their next crop with barley yellow dwarf in mind."

Experts hope ongoing research can provide controls for barley yellow dwarf. Field tests show that in-furrow insecticide treatments may help control the aphids that carry the virus.

"That could help us," Hudson said. "But until then, we'll just grin and bear it. At least the wheat Georgia farmers do make is valuable."