New tomato to the rescue

The whitefly in Texas finally may be sending up a surrender flag to tomato processors in the state, thanks to a Texas AgriLife Research scientist developing a new variety that resists the virus spread by this pesky insect.

A 10-year battle against the insect all but wiped out the tomato industry in Texas, but the new tomato is encouraging small processors to stay in business.

“We first saw this new virus around 2002 or so,” says Kevin Crosby, AgriLife Research vegetable breeder. “There were strains of this virus complex always in the Rio Grande Valley, but they weren’t nearly as easily spread by the whitefly as this new strain that originated in the Middle East, and then went from Florida to Mexico, and then came to Texas.

It spreads like a wildfire. I’ve seen a 50-acre field just plowed under because they couldn’t get a single tomato out of them. There are so many whiteflies down there in that subtropical region you really can never completely eliminate whiteflies. You can’t do it.”

Industry in ruins

The researcher says tomato plants as young as 3 weeks old can be infected by the whiteflies, causing leaves to curl and turn yellow, ultimately killing the entire plant.

Tomato processing in the Rio Grande Valley just pulled the plug rather than fight the fly, industry officials say. “Whiteflies just devastated the tomato industry here,” says Buddy Ault, owner of Rio Valley Canning Co. in Donna, Texas. Before the whitefly, the Rio Grande Valley produced about 40,000 acres of tomatoes.

“About five years ago, we noticed that plants were dying just when the fruit was about to mature. The leaves turned yellow and cut off nutrients to the fruit, causing tomatoes to stay green on the inside,” Ault says.

Growers first blamed the whitefly, but realized a virus carried by the whitefly was the culprit, Ault says. “We asked Texas AgriLife Research about the possibility of developing an open-pollinated, virus-resistant variety,” he says.

“Dr. Paul Leeper, who was a scientist at [AgriLife Research in] Weslaco for decades did a lot of the early work on hot-climate processing tomatoes. As a result, he built a lot of very good varieties for the industry. In fact, his tomatoes at one point were the most popular tomatoes in tropical places because they could tolerate the heat,” Crosby notes. “But we found out that they could not tolerate the new viruses that have been brought in by the whitefly.”

Crosby called upon colleagues in Florida and Taiwan, who had identified tomato genes that provide resistance to the viral disease, in seeking plants to cross with the Texas varieties. He got a supply to test from Peter Hansen at the World Vegetable Research and Development Center in Taiwan, as well as from Jay Scott, a tomato breeder at the University of Florida.

“We were able to cross those lines with our Weslaco lines and generate material that was adapted to Texas and that had good processing qualities,” Crosby says.

For now, the new tomato variety called T-5 is being tested by some producers in the Rio Grande Valley, and Crosby reports the results as highly encouraging. “Because it combines two distinct virus-resistance genes, resistance has been outstanding.”

Crosby plans to continue the virus-resistance research for the fresh tomato types and to develop varieties suited for growing in the state’s different climates.

Phillips is with Texas A&M Agriculture Communications, College Station.

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whitefly warrior: Kevin Crosby, Texas AgriLife Research vegetable breeder, says a new whitefly-resistant tomato variety
T-5, which he recently developed, is a boon to the Texas industry.

This article published in the July, 2012 edition of THE FARMER-STOCKMAN.

All rights reserved. Copyright Farm Progress Cos. 2012.