The Future of Citrus

Greening disease threatens the very identity of the Indian River District, but from the grove to the laboratory, the fight is far from over
USDA Agricultural Research Service technician Kathy Moulton inspects young citrus plants for symptoms of greening disease.

At the age of 7, I could deftly halve and section a grapefruit with a paring knife. Winters were long in Illinois, and our family looked for a slice of sunshine during months when shadows appeared only 20 of 90 days. We found it in Indian River grapefruit. My sister and I would inhale the pieces two or three at a time until the juice ran down our faces. On the really bitter days, we drizzled on some maple syrup and popped them under the broiler. More than 30 years later, I moved to the center of the universe for grapefruit, but, far from taking it for granted, I have come to appreciate the special nature of the fruit even more.

For decades, Indian River grapefruit was specified by customers of packers and exporters such as Pat Rodgers, former president of Greene River Marketing. “In the early 2000s, the state of Florida produced over 50 million boxes of grapefruit, with the majority grown in the Indian River District,” he says, adding that it is the ratio of sugar to acid that makes our grapefruit so sought-after in the U.K., Japan, France, Holland, Canada and here in the U.S. “As greening has infiltrated Florida grapefruit, we have averaged, in the last three years, around 5 million boxes of grapefruit.”

Citrus greening is the latest, and most challenging, threat to our beloved fruit, but it is hardly the first. Dan Richey, president of Riverfront Packing, looks at the various reasons production is decreasing. “From 2002 to 2008, we had land being developed at a rapid rate and grove land was being bought up,” he recalls. “The hurricanes of 2004 were a real kick in the teeth, too.” More recent hurricanes roaring up the middle of the state have caused crop losses upwards of 50 percent, since once the grapefruit hits the ground, it is not saleable. Then came citrus canker disease. “At the time, we thought canker was going to be devastating,” says Richey, “but compared to greening it was a walk in the park.” Like canker, citrus greening, full name huanglongbing, but more commonly referred to as HLB, is caused by bacteria vectored and transmitted by a tiny insect known as the Asian citrus psyllid. The bacteria produce a starch that can plug the vascular system of the plant, inhibiting the exchange of water and nutrients.  Greening was reported in China in the early 1940s, reached the U.S. through new open-port policies in 2005, and is now in Texas, Florida and California, as well as all citrus-producing countries worldwide. The disease affects all orange and tangerine varieties, but is most devastating for grapefruit.

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