July 8, 2011

Florida adapting to changing temperatures

Here in southern Hillsborough County, about as far as you can go on County Road 672, Jay Scott walks amid rows of tomato plants, imagining the future.

In the future, changing weather patterns could make Florida hotter and wetter than today – conditions that could wreck the state's tomato industry.

With that in mind, Scott and his crew at the University of Florida's agricultural research station are reinventing the tomato. They're breeding tomatoes that thrive in higher temperatures and resist the diseases that come with wet conditions.

In the short term, the new tomato varieties could give the state's farmers more time to grow and harvest their crops. In the long term, a more heat-tolerant tomato could become the go-to variety as the climate continues to shift, Scott said.

Weather watchers got a glimpse of the future this month when the federal National Climate Data Center in Asheville, N.C., released new once-a-decade "normal" temperatures for communities across the United States.

The normals represent the average of daily temperature readings over 30 years. The numbers released this month cover 1981 through 2010, a range that includes some of the hottest years in recorded history.

The new numbers confirm what scientists have said for nearly 25 years: The world is getting warmer. Over the last 50 years, normal temperatures have crept up decade after decade, according to the data center.

The change between 2000 and 2010 ranges from a half-degree during a Tampa summer to two degrees for a Detroit winter. Those are small numbers, but, like revolving interest on a credit card, they add up rapidly.

"It is a big deal," said Anthony Arguez, who compiled the new numbers.

Across Florida, temperature changes can depend on how urban or rural a location is.

At Tampa International Airport, for example, the difference between July's new average temperature (83) and 2000's average (82.7) is three-tenths of a degree. Twenty miles to the east, July in Plant City is four-tenths of a degree hotter now than a decade ago.

Meanwhile, in eastern Pasco County, rural St. Leo's July normal jumped by twice that amount, from 81.9 to 82.6 degrees.

Changes in Tampa Bay communities pale compared those elsewhere, however. In the nation's midsection, states from Michigan to Missouri to Montana have seen their average winter temperatures warm by as much as four degrees.

Warmer winters have drawn armadillos north from their Deep South stomping grounds. They've also let slip hordes of mountain pine beetles, which used to be held in check by long cold winters. As their populations have exploded, they've killed thousands of acres of Rocky Mountain pine forests.

So far, the Southeast has avoided the kind of environmental changes affecting other states. But climatologists and agriculture experts aren't resting easy.
In Florida, they're worried about tomato spot.

The fungus thrives in the Florida's warm, wet summers and quickly destroys tomato plants unlucky enough to become infected. State agricultural experts see a future when summer heat and humidity take hold sooner and last longer, putting at risk the tomato harvest in Ruskin and beyond.

That possibility has Scott and other UF researchers working to engineer a tomato that's immune to spot and will produce fruit at temperatures in excess of 75 degrees, the limit of conventional tomato plants.

While they're at it, the researchers are also trying to breed tomatoes that can survive colder winters as well. That's because the same forces pushing up long-term temperatures also make it harder to forecast the weather from year to year, said David Zierden, the state climatologist.

"It's not necessarily a one- to two-degree change in average temperature where the risk lies," Zierden said. "The risk is going to be in the extremes."

That could mean colder cold snaps, a special concern for citrus and strawberry growers – and, as folks around Plant City learned last year, for the neighbors who share groundwater with them. Round-the-clock pumping to protect strawberry fields depleted local wells and opened sinkholes.

UF researchers are working on technology to protect strawberries from the cold without water. That could mean covering plants with fabric instead of ice – a potentially expensive and labor-intensive change, but one that could pay off if cold snaps continue.

"We don't know if it's going to be enough to pay for the technology over time, but it looks promising," said Craig Stanley, assistant director of the Balm research station.

Florida is likely to become a proving ground for other techniques aimed at helping both farmers and their crops adapt to a changing climate.

Federal agriculture officials this month injected $6.9 million into those efforts. Of that, $1.9 million will go toward helping farmers, who provide much of the East Coast's winter vegetables, prepare their fields and their bank accounts for changing temperatures.

"Farmers like to see a clear picture in their minds," said Clyde Fraisse, an assistant professor of agriculture and bioengineering. "All the uncertainty we're seeing in climate change makes it very hard to gauge what can be done."
Another $5 million federal grant will help develop a strain of corn that can thrive in hotter temperatures.

Why grow Midwestern corn in Florida?

"Florida is kind of the future of the Midwest," said UF corn expert Curtis Hannah. "We can torture-test the corn here."

Hannah will work with researchers in Iowa and Wisconsin to genetically engineer corn that can thrive in temperatures that are already proving to be more than conventional corn can handle. Hannah said it could be more than a decade before heat-tolerant corn comes to market.

In the meantime, the temperatures continue to creep upward.

"From a long-term standpoint, developing tougher plants is a difficult thing to do when you don't know what the temperature's going to be like," Stanley said.

"It takes a long time to develop plant varieties."

By Kevin Wiatrowski, The Tampa Tribune [Source]

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