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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.
-Contunued

5/25/2007 3:31:55 PM

Www.extremepumpkinstore.com

-continued
"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.

5/25/2007 3:32:14 PM

Ctpumpkin@optonline.net

Wonderful!

Good post Tom.

5/26/2007 10:10:09 PM

porterville, calif.

Im in Tulare County in the Central Valley here. I have 8 tomato plants going hope they don,t get this . I will have to keep a close eye on it.

5/27/2007 2:31:52 AM

Wilmington.Ma.

Great post Tom!

5/27/2007 10:29:13 AM

Lilburn, GA

Tom, I bought 14 plants through mail order in Lomita, CA and one of them is exhibiting some of the symptoms you describe. I plan to destroy it today. Should I report it to my county extension agent?
Thanks, Monica

6/3/2007 7:16:25 AM

Www.extremepumpkinstore.com

Monica,
I would before you destroy it, maybe they will want to test it.
Tom

6/3/2007 11:25:58 AM

Lilburn, GA

Tom,
I did some research on the web and found that TYLC is now fairly common in GA so now I'm not as alarmed. But I definitely have it, thankfully on only one of my 36 tomato plants. Interesting, the affected plant is a hybrid Lemon Boy and most of my plants are heirloom varieties.

Lo and behold I noticed the dreaded culprit whiteflies flitting about yesterday, too, and my gardens are generally fairly pest free (knock wood).

I already spray weekly with Neem and I may now alternate that with a pyrethrin. Also, our local GA garden guru Walter Reeves has a great idea for a trap so I may try it. I don't want those critters to spread out into the field where my pumpkins are!

From walterreeves.com (a great site for Southern gardeners!):
"Whiteflies can be managed with a variety of strategies but it is almost impossible to eliminate them. Scientists have discovered that the color yellow, to a whitefly, is like the sight of neon to a compulsive gambler. They fly directly toward the yellow object, hoping it is attached to a plant they can infest. Crafty gardeners have taken this information and devised whitefly traps that lure them to a sticky death.

My favorite trap is simplicity itself. Drive two, four-foot long wooden stakes into the ground on either side of a plant where you've seen whiteflies. Upend a yellow plastic cup ( Solo (tm) brand works great) onto each stake and nail or staple it in place. Paint the outside of the cup with thick automotive oil treatment (STP (tm) is an example).

Whiteflies cruising in the vicinity land on the yellow cup, hoping for a good meal. Instead, it is the last landing they ever accomplish, for the sticky oil treatment holds them in a gooey grip of death. It won't eliminate all of your whiteflies but you will be amazed at the number of insects caught on the cup in just a few days."

6/4/2007 12:44:13 PM