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Florida Oranges Flourish Despite This Winter's Cold

While most of the nation has suffered through a colder-than-usual winter, it appears that the Sunshine State has been spared by Old Man Winter thus far. Bone-chilling lows did not find their way into the state's citrus groves and growers couldn't be more thankful. Florida is the largest producer of oranges, accounting for about seventy percent of the total production in the United States, according to the Agricultural Marketing Resource Center website.

"We're looking forward to things warming up [in Lake Wales, Fla.]," Vic Story, a grower and President of the Story Companies said.

Negative Cold Effects

Dave Crumbly, vice president of Agricultural Services at Florida's Natural Growers said that cold weather is one of the biggest risks to citrus fruit growers.

"With the degree of cold across the county, we have been very fortunate to have escaped with basically no damage so far this winter. Fortunately, the jet stream has worked to our advantage," Crumbly said.

Typically, citrus can be damaged by four or more hours of temperatures below 28 F, but Story said luckily his grove did not see a period of extended cold.

"There was maybe only a handful of night's where the temperature got just below the freezing mark and it was for no more than an hour," AccuWeather Agricultural Meteorologist Dale Mohler said.

"Most of "citrus country" was outstretched from Ft. Myers to Lake Okachobee in Florida with little chance of below-freezing temperatures," Mohler said.

"Freeze season is usually from mid-December to the end of March and an early freeze would have hurt the area but it's safe to say they've escaped the cold," Mohler said.

Lower-than-normal temperatures have also been known to speed up a process called "greening" which is a bacterial disease and a growers greatest fear for crops. Greening is also known as "huanglongbing" and is spread by a disease-infected insect or psyllid from Asian decent. The disease has effected Florida's citrus country since 2005.

"The bacteria feeds on young, tender leaves and blocks the vascular flow of nutrients throughout the plant like an artery clogging blood to the heart," Crumbly said.

Southern Gardens Citrus worker Laura Contreras marks an infected citrus tree at the Southern Gardens Citrus grove Friday, Aug. 31, 2007 in Clewiston, Fla. a)(AP Photo/Luis M. Alavrez)

The bacteria weakens the trees causing the fruit to become small, misshaped and the juice to be bitter. In turn, the grower loses serious production.

"Colder weather exacerbates greening," Story said.

While colder weather doesn't hurt the bacteria, the infected tree's already weakened system can deteriorate quickly.

Positive Effects of the Cold

However, a dip in temperatures is not always a bad thing.

"Between 30 F and 35 F is a window where oranges tend to turn sweeter. It's the natural sugar sweet spot," Mohler said.

Dr. Fred Gmitter of the University of Florida's Citrus Research and Education Center said that may be a bit of an old wives' tale.

"Color development is enhanced by the cold. The breakdown of chlorophyll [the green color in oranges and other citrus fruit] is accelerated by cold, usually coinciding with the maturing of some early ripening varieties," Gmitter said. "So they 'become sweeter' while maturing and changing color simultaneously."

Gene Albrigo, Gmitter's associate, resident emeritus citrus and climate expert added that sugars build up slowly and actually don't build up as fast if it is too cold.

"The perception of sweeter [fruit] is partly due to reduced acidity, which declines in the fall and winter. It declines more slowly if it is cold than if it is warm. No matter what kind of a winter we have, the fruit is perceived as sweeter and more acceptable to most palates," Albrigo said.

The southeastern United States is often not familiar with jet streams that bring wintry weather, however many places experienced the ice and cold this winter. Luckily, citrus groves in Florida were some of the few areas spared from detrimental temperatures.