By Brad Haire
University of Georgia
The diseases caused by tospoviruses can greatly reduce crop
yields or outright kill many of the crops grown in Georgia and
the Southeast. They cause millions of dollars in damage each
year.
That’s why industry and farm group representatives and
scientists from across the Southeast will meet Dec. 2 at the
University of Georgia’s Tifton, Ga., campus.
They want to compare notes and hear how Georgia and other states
have dealt with these viruses, said Alex Csinos, a plant
pathologist with the UGA College of Agricultural and
Environmental Sciences.
The last such conference was a much smaller one in 1997 in
Tifton.
Tospoviruses are plant viruses carried by small insects called
thrips. Thrips larvae get the viruses when they feed on infected
plants. When the larvae mature, they can carry the viruses to
healthy plants.
Thrips like Georgia’s subtropical climate, Csinos said. And they
constantly bombard crops.
As many as 10 million thrips can visit an acre of tobacco in
Georgia every day during the growing season, he said. It takes
about 120 days to grow tobacco.
“Georgia could be considered the epicenter for tospoviruses in
the Southeast,” Csinos said.
Tospoviruses cost Georgia farmers an estimated $50 million every
year in lost yields and control measures, he said.
The most infamous tospovirus in Georgia is the tomato spotted
wilt virus. It blew into Georgia in the late 1980s and quickly
began hurting many of the state’s crops.
To successfully grow peanuts in Georgia, farmers now plant
resistant varieties. The No. 1 variety planted in Georgia is
Georgia Green, developed at the Coastal Plain Experiment Station
in Tifton.
“There’s not a peanut breeding program in the Southeast that
doesn’t have to consider tomato spotted wilt resistance first,”
said Bob Kemerait, a peanut plant pathologist with the UGA
Extension Service.
Peanut farmers now can lower the risk of their crop’s getting
the disease by using the TSWV Risk Index, a multidisciplinary
guide developed by UGA scientists.
TSWV also attacks and causes major damage to Georgia’s tobacco
crop. It infected an estimated 25 percent to 30 percent of the
crop this year. It’s been worse in other years. The virus
infects vegetables grown in Georgia, too, such as tomatoes and
peppers.
Another tospovirus called iris yellow spot was identified late
last year in Georgia Vidalia onion fields. IYSV has caused major
problems for onion growers in the Pacific Northwest and South
America. Agricultural officials are now waiting to see how IYSV
will affect Georgia’s official state vegetable.
Many plants in Georgia can be hosts for tospoviruses, said
Natalia Martinez-Ochoa, coordinator of the Plant Virology
Laboratory in Tifton.
“It’s easier to list the weeds in Georgia that are not hosts for
tospoviruses,” she said, “than list the ones that are.”
Tospoviruses don’t just attack row crops, she said. The
ornamental industry is also concerned about them. They can cause
damage to certain ornamental crops like petunias, vincas,
zinnias and impatiens.
To find out more about the UGA tospovirus conference, call (229)
386-7230 or e-mail nmartinez@tifton.uga.edu.
