By Michael E. Miller
By Allie Conti
By David Villano
By Jose D. Duran
By Michael E. Miller
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By Kyle Swenson
By Luther Campbell
With hurricane season once again upon us, Mother Nature could conspire to quickly defeat the entire endeavor. The alternative -- letting the disease run its course and become endemic -- is not pretty. And so, onward march the canker soldiers.
Like the plants it attacks, the disease has origins far from South Florida. Commonly known as Asiatic citrus canker, Xanthomonas axonopodisdoes not kill trees (nor is it harmful to the human body), but it causes rough brown splotches on leaves and fruit. Canker-infected lemons, limes, oranges, and grapefruits with lesions are edible, but so ugly they are difficult to market. A severe case can also cause a citrus tree to lose leaves and prematurely drop its fruit. Florida is a welcome haunt for these bacteria, which multiply rapidly, especially in hot, humid weather. “They're just waiting for water,” says Lou Lodyga, a pathologist for the Florida Department of Agriculture's division of plant industry. “You get driving rains and that spreads them like wildfire.” Scientists call trees with symptoms infected. Nearby trees are termed exposed.
This scourge, this shade-sucking, fruit-snatching curse, has wreaked havoc in Florida twice before. Beginning about 1910 the state spent six and a half million dollars to root out the first canker epidemic by slashing and burning infected trees. Workers also pruned leaves on exposed trees within 50 feet of a canker outbreak. Back then citrus groves generally were much smaller and more scattered. “They took really drastic action,” says Lavern Timmer of the University of Florida's Citrus Research and Education Center in Lake Alfred. “They burned everything, nurseries and groves. And they basically had people running around with flame throwers, dousing the trees with gasoline and burning them on the spot. And they disinfected everybody with mercuric chloride. I'm amazed some of the people lived through that.” These early terminators wiped out most of the canker by the Twenties and managed to subdue various flareups in the later Twenties and Thirties.
Xanthomonas axonopodis did not pop up again until the mid-Eighties. This time it posed a more substantial threat. The Sunshine State's population had swelled, and along with it, the likelihood that people and machines would inadvertently spread the bacteria. Moreover harvesting orange and grapefruit trees had bloomed into a multibillion-dollar industry that was concentrated in large central Florida groves. Plant pathologists stumbled on to the pathogen in the Sebring area northwest of Lake Okeechobee while looking for another, far less virulent strain. They traced the origin of the outbreak to a citrus inspector's home. “Apparently he had been doing some kind of experiments in his yard or something,” Timmer recounts. “And it spread to a grove.” Grove owner Ed Smoak promptly destroyed 400 acres of trees. “He just burned the whole thing,” Timmer adds. “The inspector had passed away before they ever found the canker there. So he was off the hook.”
For several years in the Eighties, Timmer studied citrus canker in northeastern Argentina, where the disease has been endemic for about 25 years. Citrus growers there and in southern Brazil must routinely spray their groves with copper compounds that suppress the disease. They also have difficulty exporting the fruit to nations with tight agricultural inspections.
The Floridian outbreaks of the mid-Eighties were confined to a few groves in rural areas in the central part of the state. Authorities took swift action. Basing its decision on South American research, the state defined all citrus trees within 125 feet of an infected specimen as exposed and promptly burned them. Disaster was again averted.
But the canker returned in the fall of 1995. Unfortunately this time it was detected in a yard near Galloway Road and West Flagler Street, where the chances of it spreading were high. “That was the start of this nightmare,” recalls Lodyga. Scientists suspect the infected plant arrived from Brazil or Argentina. With a $2.2-million budget and 120 employees, the state revived its citrus canker eradication program and imposed a quarantine on a fourteen-square-mile area encompassing Westchester and Sweetwater. Several dozen inspectors began to search for more canker in Miami-Dade and Broward. In 1996 officials informed legislators of the danger, but they only appropriated a million dollars for the effort. The following year they approved another three million.
That was not enough to finance the widespread inspections and removal required to stop the spread. Many legislators remained either ignorant of the impending catastrophe or unconcerned; some argued over who should foot the bill. In 1997 agriculture commissioner Bob Crawford tangled with Lawton Chiles when the former governor proposed forcing the citrus industry to tap into an emergency fund held by growers. That year the decision-makers were preoccupied with a more obvious problem: Mediterranean fruit flies, which burrow into fruit and vegetables and deposit larvae. In 1997 and 1998 the state spent $32 million dropping insecticides from airplanes onto farms and groves from Tampa to Orlando. The program saved millions of dollars in crops. Meanwhile rains and high winds were propelling airborne bacteria throughout South Florida. Beginning in 1997 growers in Collier, Hendry, Hillsborough, and Manatee counties reported outbreaks. Workers quickly destroyed hundreds of acres of trees.
Litigious citizens also hampered the effort. Miami lawyer John Ruiz filed a class-action lawsuit in October 1997 on behalf of a group of homeowners who wanted compensation for their hacked-up trees. A state judge agreed and barred the agriculture department from cutting down exposed trees (although workers could still chop infected trees). It wasn't until April 1999 that a Third District Court of Appeal panel overturned the ruling, saying trees exposed to the bacteria had no value. But by then the canker forces had lost eighteen months. Another summer of thunderstorms and hurricanes had spread the disease even more.