UGA leads effort to swat down major vegetable disease
April 5, 2008
In the Southeast, thrips are tomato and pepper farmers' No. 1 enemy. The tiny, plant-feeding bugs carry a disease that can devastate their crops. A $1.75 million grant will help experts with the University of Georgia and other universities in the region develop ways to stop the damage.
"The key pest for Georgia, north Florida and up through the Carolinas are no doubt thrips-vectored viruses," said David Riley, a research entomologist with the UGA College of Agricultural and Environmental Sciences. "It's the one that will make or break the crop."
Over the next four years, Riley will lead a multistate, interdisciplinary team of experts from CAES, the University of Florida, Clemson University and North Carolina State University. The goal is to drastically reduce the risk and damage of the tomato spotted wilt virus. The U.S. Department of Agriculture Cooperative State Research, Education and Extension Service will fund the effort.
Each university included in the grant has faculty working on ways to control TSWV and thrips in their state. This grant will provide the funding and direction needed to coordinate the efforts into strategies farmers can use throughout the region, said Terry Kelley, a vegetable horticulturist with UGA Cooperative Extension.
"Several individual variables that impact tomato spotted wilt virus on tomatoes and peppers have been identified in recent years. This grant will provide the means to look at combinations of these variables and determine the best overall system to use in combating it," Kelley said. "Hopefully the result will be a strategy that growers can employ to reduce the impact of TSWV every season on their farms."
TSWV is mainly carried by tobacco thrips and Western flower thrips. The disease costs tomato and pepper farmers in Florida, Georgia, South Carolina and North Carolina as much as $100 million in preventive management and damage annually. The four states combined produce half of the nation's fresh tomato and pepper supply, worth $1.3 billion annually. "This is the hot zone for tomato spotted wilt virus in the U.S.," Riley said.
The virus can destroy 20 percent to 30 percent of a field in any year or all of a field in a bad year, said Bill Brim, a vegetable farmer in Tifton, Ga. The few TSWV-resistant varieties available to farmers now can succumb to the virus over time.
"This virus can devastate us." said Brim, who is president of the Georgia Fruit and Vegetable Growers Association. "We're excited about this grant. The research and work that will come from it will help us stay ahead of the game on this in the future."
Riley hopes to develop a risk index, or a planning tool, that farmers can use to score their crop's chances of getting the disease. By combining resistant plants, different types of plastics to cover planting beds, thrips population predictions, chemicals and chemical application times, farmers can reduce the damage the disease causes.
In the mid-1990s, CAES experts developed a similar index for the disease in peanuts. It helped farmers drastically reduce the damage it causes that crop annually.
"We won't eliminate the virus. It will always be around," Riley said. "But I am confident in time we will be able to eliminate the damage it causes."