By:
Carole L. Jaworski

Source(s):
Jane Polston (941) 751-7636
Ernest Hiebert (941) 392-7246

GAINESVILLE—A new virus that could ruin Florida’s $500 million tomato industry and spread throughout the South has been detected by researchers with the University of Florida’s Institute of Food and Agricultural Sciences.

Tomato yellow leaf curl virus, which prevents plants from producing marketable tomatoes, turned up last weekend in Charlotte, Collier, Dade and Sarasota counties. Jane Polston, plant pathologist with the UF/IFAS Gulf Coast Research and Education Center in Bradenton, discovered the virus on small tomato plants being sold to consumers at retail nursery stores.

The virus affects only plants and is no threat to humans or animals. What little fruit may be produced is edible but it’s too small to be marketable.

“We have a potential epidemic on our hands,” she said. “I’m not one to exaggerate, but there won’t be any tomatoes left in Florida or the South if this disease is allowed to spread. It comes at a bad time because state regulatory officials already have their hands full trying to stop Medflies and citrus canker.”

Polston said the virus has never been detected in the United States until now. First identified in Israel in 1959, the virus spread to Mediterranean and Caribbean countries. In 1992, it destroyed 90 percent of the tomato crop in the Dominican Republic. The virus may have entered the U.S. on infected plants or it may have been carried by whiteflies from the Caribbean.

After Polston identified the virus in her Bradenton laboratory, the Florida Department of Agriculture and Consumer Services issued a stop sale order to two Dade County nurseries that supply retailers with tomato plants for home gardeners. Additional tomato transplant producers in South Florida are being surveyed by the FDACS Division of Plant Industry this week.

“There are still some infected plants at retail outlets or in home gardens,” Polston said. “We’re alerting growers, retailers and consumers to look out for infected plants. If you find an infected plant, don’t just throw it in the trash. Destroy the plant to prevent the virus from being spread.”

The virus, which has a broad host range that includes many weeds, is spread by whiteflies that feed on plant foliage.

Key symptoms to watch for are severely stunted plants with deformed leaves showing yellow leaf margins. Leaves may be cupped, reduced in size and leathery. Plants will show a bushy appearance. Infected plants lose vigor, drop flowers prematurely and have little or no fruit set.

Ernest Hiebert, UF/IFAS professor of plant pathology in Gainesville, said the virus epidemic appears to be in its early stages and could be contained during the next two months before the fall tomato growing season begins.

“Both home gardeners and commercial growers should make sure their plants are virus free,” Hiebert said. “Everyone should be much more vigilant about controlling whiteflies that spread the virus.”

UF/IFAS researchers recommend controlling whiteflies with pesticides and separating tomato transplant sites from production fields and reducing weeds harboring the virus to reduce the effect of the disease on Florida’s 50,000 acres of field-grown tomatoes, greenhouse tomatoes and tomato transplants.

Hiebert, Polston and Jay Scott, professor of horticultural science at the UF/IFAS Bradenton research center, are developing new tomato varieties that are resistant to the new virus. They hope to have a resistant tomato variety in three or four years.

Homeowners or growers with questions should contact their local UF/IFAS county extension office. Information on the disease also is being posted on the UF/IFAS home page: http://hammock.ifas.ufl.edu/.

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