Research came full circle on April 16 as the Animal and Plant Health Inspection Service (APHIS) amended the Karnal bunt quarantine areas in Arizona, California and Texas, according to a Texas AgriLife Extension research scientist. "The research is finally paying off," says Charlie Rush, AgriLife research plant pathologist, of the action by APHIS to lift the restrictions on the interstate movement of Karnal bunt regulated wheat from certain areas in all the three states.
Texas has no further restrictions, however, Arizona still has one remaining area under quarantine. "Sometimes it takes years to realize the impact of a specific research project, but this is a perfect example of where research allowed the government to make changes, and today the producers get the final payoff," says Rush.
Rush and his associates, through work in the AgriLife Research High Plains Plant Pathology Laboratory and Plant Disease Diagnostic Laboratory, spent five years working on Karnal bunt to provide federal agencies information demonstrating the disease would not explode and cause significant disease outbreaks, even under optimum environmental conditions.
Karnal bunt is a fungal disease of wheat, first observed in the U.S. in 1996. The disease causes wheat kernels to be damaged by fungal teliospores. Each infected kernel can produce many reproductive spores and aid in the spread of the disease, says Rush. Bunted wheat can have an impact on flour quality by causing a fishy odor, but it is not toxic to humans or livestock.
In 2000, a federal order under the Plant Protection Act prohibited or restricted the movement in interstate commerce of any plant, plant part or article to prevent the dissemination of a plant pest within the U.S. "When they first found Karnal bunt near Wichita Falls and San Saba, TX, everything within a certain diameter around the field was quarantined," says Rush.
"While it was never really a significant disease, the political ramifications and export issues grew and many producers suffered great losses." Texas A&M System economists at the time estimated the fungal disease hurt the Rolling Plains regional economy to the tune of more than $27 million in the first year.
"The real tragedy of all of this was the producers it affected," says Stan Bevers, Texas AgriLife Extension Service economist in Vernon. "They had restrictions placed on them from moving their wheat and cattle that had grazed on the pastures. Producers found their land values dropping and their equity evaporating."
Karnal bunt can infect flowering plants if they come in contact with spores, primarily when temperatures are cool and rainfall and humidity are high. Researchers warned producers the spores could be spread from field to field on plants, seeds, soil, farm equipment, tools, vehicles or on the wind. Once in the soil, the spores can survive for as long as five years.
Rush says the five-year waiting period with negative results in these fields is what has finally been met, allowing the restrictions to be lifted. David Marshall, a Texas A&M wheat researcher and director of the Dallas screening lab, which handled all the Texas samples at the time, started the early diagnostic work, but he later moved to a new position with the USDA-ARS in North Carolina.
With Marshall's departure, Rush says he was contacted by George Nash, state operational officer for APHIS in Austin, to pick up the research needed. "Even though Karnal bunt wasn't a concern in the Texas Panhandle, as a wheat pathologist I just felt responsible to the growers in the state and took on the project," says Rush.