May 22, 8:23 PM EDT

*Tomato-Killing Virus Detected in Calif.*

By LAURA KURTZMAN
Associated Press Writer

SACRAMENTO (AP) -- An insect-borne virus that has killed tomato plants
across Central America, Florida and Georgia has been detected in
California for the first time.

The virus, known as tomato yellow leaf curl, devastated crops in the
Dominican Republican and in Mexico, forcing those countries to curtail
the growing season to contain the spread of the disease.

Tomatoes are California's eighth largest crop. The state supplies the
vast majority of the nation's processed tomatoes - 95 percent, according
to the California Tomato Growers Association.

In Arkansas, federal statistics show about 1,200 acres of tomatoes were
harvested last year.

"Where this virus is present, it will absolutely kill the tomatoes,"
said Ross Siragusa, president of the association, which represents
farmers who supply the state's $2 billion a year processed tomato
industry. "It's a very difficult disease to fight."

California has some natural advantages in stopping the disease from
spreading that other locales lack.

The cold, wet winters in the Central Valley, where most tomatoes are
grown, act as barriers to the bemisia white flies that carry the
disease. The flies are native to Imperial, Riverside and San Diego
counties in the southern part of the state, but not to any counties in
the Central Valley.

"We're cautiously optimistic that those conditions are going to be very
unfavorable to establishment of the virus," said Robert Gilbertson, a
plant pathologist at the University of California, Davis.

The diseased plants were found in March at a greenhouse in Brawley,
which is near the border with Mexico. Experts do not know how the virus
spread there. It could have been brought by tomato transplants from
Mexico or Texas. Or the virus could have been carried by bemisia flies.

The virus causes tomato plants to become stunted and grow abnormally
upright. Flowers usually fall off before the fruit sets. And leaves are
small and crumpled with an upward curl. They also turn yellow.

Experts say growers or backyard gardeners who detect the disease should
destroy the infected plants and look for the flies. If bemesia flies are
present, the disease is likely to be spreading fast, and the entire
field may have to be destroyed and treated with insecticide. Nearby
weeds also can carry the virus and may have to be sprayed.

In Florida, where the virus has become well established, Gilbertson said
growers have had to make heavy use of pesticides and have planted tomato
varieties that are more resistant to the disease. But flies may become
resistant to the pesticides over time.

Siragusa said his group has alerted growers, greenhouses and seed
companies that the virus has spread to California. But, he said,
controlling the virus will be especially hard because so many tomatoes
are grown in backyards.