Florida's citrus growers battle to save fruit from killer bacteria

Disease that originated in China ravages orange trees, causing value of orchard land to tumble

PUBLISHED : Monday, 13 January, 2014, 11:42pm
UPDATED : Tuesday, 14 January, 2014, 3:51am

The sprawling Florida citrus orchard that Victor Story toured recently looked like a steal. For sale at US$27,500 per hectare, the investors who owned it were going to lose money, and potential buyers like Story might have stood to reap a handsome reward.

But as he bumped along the 16 hectares of groves in a large SUV, Story was taken aback by the sickly look of the trees. Their leaves were shorter than normal and yellowing. Full-size oranges were still apple green. Other mature oranges that should have been the size of baseballs were no bigger than ping-pong balls.

"That fruit's never going to be of any value," said Story, 68, who has been growing fruit all his life. He said his pickers wouldn't even bother to reach for it. "It's going to fall off the tree; it's never going to get squeezed," he said. "These investors paid US$15,000 an acre (US$37,500 per hectare) for that grove. I know because they bought it from a friend. I frankly don't think it will sell for US$11,000."

What Story saw in the orchard in Polk County, Florida, wasn't an anomaly. It's the new norm in the Sunshine State, where about half the trees in every citrus orchard are stricken with an incurable bacterial infection from China that goes by many names: huanglongbing, "yellow dragon disease" and "citrus greening." Growers, agriculturalists and academics liken it to cancer. Roots become deformed. Fruits drop from limbs prematurely and rot. The trees slowly die.

The bacteria is spread by a tiny, invasive bug, also from China, called Asian citrus psyllid. It acquires the bacteria while feeding on the leaves of infected trees, then transmits it when feeding on healthy trees - akin to the way mosquitoes transfer malaria.

Psyllids were first detected in a Broward County, Florida, garden in 1998 and spread to 31 other counties within two years. The Asian strain of the bacteria was discovered in 2005 just south of Miami. The disease ruins the look and taste of the fruit but isn't known to harm humans.

Florida citrus, which provides up to 80 per cent of America's orange juice, has been hardest hit, but the disease - which also has an African and Latin American strain - also has been detected in Georgia, Louisiana, Texas, Arizona and California. It has spread to other parts of the world, including Mexico, India, sub-Saharan Africa and Brazil. In each case, the impact to citrus has been devastating.

Worldwide concern prompted 500 scientists from more than 20 nations to gather in Orlando last February for a conference on huanglongbing. Although nearly US$80 million has been poured into research on the disease, scientists still don't know how to eliminate the bacteria or remove it from trees.

Even those who are optimistic about a scientific breakthrough admit that if the infection continues unabated for another decade or so - admittedly a worse-case scenario - Florida's US$9 billion citrus industry could be destroyed.

"What's at stake is orange juice on the breakfast table," said Michael Sparks, chief executive of Florida Citrus Mutual, a trade association. "I don't want to indicate that's going to happen next year. With a 10-year decline, your supply will reduce."

Researchers funded by the industry, the state and the US Department of Agriculture are exploring an option that could save the trees and their citrus, but also turn off consumers: engineering and planting genetically modified trees that are resistant to the bacteria carried by the psyllid.

"Would that be accepted by the public?" Sparks asked. "You don't have to do a focus group or another survey to know it is a public concern."

Since the disease's detection in Florida City and Homestead, 36,000 hectares of citrus have been wiped out. The high cost of spraying to kill off some of the psyllids is pushing some growers to the financial brink. The average cost of producing a hectare of oranges is US$4,500, nearly double what it cost in 1995.