A tomato disease that ravaged crops in the Caribbean and
Florida has arrived in Georgia, and growers here wish it had
stayed south
of the border.

The disease is caused by the tomato yellow leaf curl virus
(TYLCV). In the United States, the virus was first reported in
Dade County, Fla., in July 1997. It established quickly, and
Florida
tomato growers soon began to feel its impact.

New to the U.S., but not to the Middle
East

TYLCV has been present in Israel for more than 40 years. It
showed up in Cuba, Jamaica and the Dominican Republic in the
early
’90s.

“The virus is transmitted by sweet potato and silverleaf
whiteflies,” said Hanu
Pappu, a plant pathologist with the University
of Georgia College of Agricultural and Environmental
Sciences.
“Infected plants suffer severe stunting and produce
virtually
no fruit.”Other symptoms include yellowing along the leaf
edges and upward cupping of the leaf — hence the name.

Hurts Tomatoes the Most

“The virus could affect a wide range of plants. But
tomato
is one of the primary crops affected,” Pappu said.
“Recently,
there was a report from Mexico that pepper plants are also
susceptible.”

Pappu and other CAES plant pathologists have been expecting
TYLCV to cross into Georgia.

“The disease is well established in Florida, and the
whitefly
population has been building up,” he said. “It was only
a matter of time before the virus showed up here.”

Hit Decatur County First

In the fall of 1998, infected tomato plants were reported in
Decatur County, Ga. “The disease was estimated at 1 percent
then,” Pappu said. “By fall 1999, it was reported in
Grady, Colquitt and Tift counties, with some fields in Grady
County
being 15-percent infected.”

At the Coastal Plain
Experiment Station in Tifton, Ga., researchers have found
infection ranging from 15 to 90 percent in experimental field
plots.

If growers notice symptoms in their fields, Pappu said, they
shouldn’t assume it’s TYLCV.

Symptoms Don’t Always Mean You’ve Got
TYLCV

“The virus causes distinct symptoms, but other
tomato-infecting
gemini viruses produce similar symptoms,” he said. “A
DNA-targeted method must be used to see whether it’s
TYLCV.”

Growers should contact their county Extension Service agent
for more on identifying and treating TYLCV.

“It’s impractical to completely eradicate the
virus,”
Pappu said. “But a combination of production practices may
minimize its impact. These include planting disease-free
transplants,
removing infected plants early in the season and managing
whiteflies
with insecticides.”

In the future, growers could choose to plant TYLCV-resistant
varieties.

“Scientists in Israel are working to breed new resistant
varieties,” Pappu said. “Here in Georgia, we’re
continuing
to monitor the disease situation closely, and we’re conducting
research to better understand and control it.”