Florida’s Abundance of Food Safety Initiatives

For the 2014-2015 season, 56 percent of all U.S. citrus, including 68 percent of oranges, 13 percent of tangerines, and 63 percent of grapefruit were grown in Florida, reports Candice Erick, the state administrator of USDA’s National Agricultural Statistics Service (NASS) Florida Field Office. (Note: The two-year designation, 2014-2015, includes only one full season. The citrus crop year begins with the bloom of the first year listed and ends with the year harvest is completed. The trees bloomed in the early spring of 2014 and the harvesting, which began later that year, concluded with Valencia oranges in the late spring of 2015.)

“About 95 percent of commercial orange production in the state is destined for processing, mostly as orange juice, the official state beverage,” Erick adds. “Florida accounts for about 20 percent of the world’s processed orange supply.”

The 2015-2016 Florida all orange forecast (released April 12, 2016, the most current information as we go to press) by the NASS Florida Field Office is 76.0 million 90-pound boxes. This total includes 36.0 million boxes of non-Valencia oranges (early, midseason, Navel, and Temple varieties) and 40.0 million boxes of Valencia oranges.

The current USDA 2015-2016 forecast of grapefruit production is 10.7 million 85-pound boxes, while the forecast for all tangerines is 1.4 million 95-pound boxes and the tangelo forecast is 390,000 90-pound boxes.

As it turns out, for all that Florida vitamin C, the big issues in the citrus industry are not related to food safety.

Rather, the dominant story concerns a dreaded quality-reducing disease called Huanglongbing (HLB), which loosely translates to “yellow dragon disease,” and is also known familiarly as citrus greening, according to Michelle Danyluk, PhD, an associate professor of food microbiology and safety with the University of Florida’s (UF) Institute of Food and Agricultural Sciences (IFAS) Citrus Research and Education Center (CREC), Lake Alfred. “HLB is currently distressing and preoccupying the Florida citrus industry,” Dr. Danyluk emphasizes.

Thought to be caused by the bacterium Candidatus Liberibacter asiaticus, HLB was first observed in China in 1919, says Keith Schneider, PhD, an IFAS professor of food science based at UF’s Gainesville campus. “Since then, HLB has seriously affected citrus production in Asia, Africa, the Indian subcontinent, and South America,” he relates.

“In 2005, the nearly century-old HLB was first confirmed in Florida on pummelo leaves and fruit,” Dr. Schneider says. “The detection occurred in the south Florida region of Homestead and Florida City.”

Since that time, HLB has been found in commercial and residential sites in all Florida counties with commercial citrus, according to Megan Dewdney, PhD, an associate professor of plant pathology and extension specialist in the CREC.

“HLB is primarily spread by the Asian citrus psyllid, a small insect, as it feeds on the leaves and young branches of citrus trees,” she explains. “The disease can also spread by moving infected plant material or by plant tissue grafting.”

Brutal Citrus Enemy

Sadly, wherever the disease has appeared, citrus production has been compromised with the loss of millions of trees, Dr. Dewdney relates, noting that HLB can cause the decline of all types of citrus trees, including orange, grapefruit, lemon, lime, kumquat, and tangerine.

“The early symptom of HLB on leaves is an asymmetrical chlorosis referred to as ‘blotchy mottle,’” she explains. “The blotchy mottle is the most diagnostic symptom of the disease, especially on sweet orange. However, symptoms can be varied and confused with other problems like nutrient deficiencies and other diseases. These include leaves that may be small and upright with a variety of chlorotic patterns that often resemble the mineral deficiencies of zinc, iron, and manganese. Some leaves may be totally devoid of green.”