The University of Kentucky is among 20 land-grant universities whose agricultural scientists are participating in a $3.5-million national initiative to eliminate scab, a disease that can cost wheat and barley producers millions of dollars a year in lost yields and crop sales.

"Our agronomists and plant pathologists will focus on three of the six scab research priorities established by the U.S. Wheat and Barley Scab Initiative," said Dave Van Sanford, a wheat breeder in the UK College of Agriculture. "One of our priorities is wheat variety development and screening. Another is epidemiology (how scab develops and spreads) and disease management. Chemical and biological control is the third area we'll be working on."

Kentucky farmers harvested an estimated 550,000 acres of wheat and 8,000 acres of barley in 1998, according to the Kentucky Agricultural Statistics Service.

Although some wheat varieties have varying levels of susceptibility to scab, no varieties are truly resistant, according to Van Sanford. The fungal disease impedes kernel development, leading to shriveled kernels, reduced yields and lower test weights. The fungus also produces a toxin that causes feed refusal in livestock. Flour millers have a low tolerance for this toxin so scabby wheat often is refused. The fungus has an adverse effect on seed viability and vigor if grain is used as seed.

"Kentucky wheat acres are potentially at risk for head scab because most of our wheat

is planted into corn stubble, either no-till or with minimum tillage," he added. "The pathogen survives on corn stubble so there is a constant source of fungal spores that can lead to infection when we have mild temperatures and rain when the crop is flowering.

"We have conducted breeding research for scab resistance for several years with support from the Kentucky Small Grain Promotion Council."

Van Sanford said 1991 was Kentucky's worst head scab year in recent memory with yield losses an estimated 16 percent. "Even using a modest wheat price of $2.50 per bushel, this would represent $10 million in losses," he said.

Nationwide, head scab cost producers about 470 million bushels of wheat, valued between $1.3-$2.6 billion from 1991-1997, according to a North Dakota State University study.

Other land-grant universities involved in the initiative will be conducting research on the three remaining national scab research priorities -- food safety, toxicology and utilization; biotechnology; and germplasm introduction and evaluation.

The U.S. Wheat and Barley Scab Initiative is funded by the USDA Agricultural Research Service. Mike Ellis, a Shelby County farmer, serves on the initiative's steering committee.