US: citrus greening said to be worse than canker

As if the Treasure Coast citrus industry didn't have enough worries.

Citrus greening disease, a bacterium classified as a biological threat by the Department of Homeland Security, has been detected on a half-dozen trees in Miami-Dade County. The findings were announced at the Indian River Citrus League's annual meeting Wednesday at the Harbor Branch Oceanographic Institution in Fort Pierce.

"This is worse than canker, worse than anything we could have found," said Richard Gaskalla, director of the Division of Plant Industry, who presented the league with the bad news. "Canker affected the appearance, not the taste."

The disease's spread would deal a second devastating blow to citrus growers and packinghouses in Florida and on the Treasure Coast. The region already is reeling from canker, a bacterial disease that damages citrus fruit and is spread by wind-blown rain.

Canker was first detected in St. Lucie County in December on residential trees after hurricanes Frances and Jeanne made landfall. Since then, canker-infected trees have been found in commercial groves on the Treasure Coast. Fruit infected with canker cannot be sold or processed.

"Obviously it presents a daunting challenge for the department and our membership," said Doug Bournique, executive director of the Vero Beach-based Indian River Citrus League. "It is very upsetting news."

Citrus greening disease is the western term for huanglongbing, which originated in Asia. Greening attacks the circulation system of citrus and ornamental citrus varieties. The disease is transferred by a tiny flying insect, the citrus psyllid, which carries greening from tree to tree. The insects can hitchhike through trees and can travel up to a mile.

The U.S. Horticultural Research Laboratory in Fort Pierce does not yet know how the disease reached Florida, but diseased trees were found Friday in Pinecrest, Cutler Ridge and Florida City, all within an 18-mile radius of Homestead. The first samples were found on a pummelo tree belonging to a family of Asian decent.

As with canker, the only known way to eradicate greening is to push and burn trees in an infested area. The disease causes premature fruit drop and small yellow leaves on one limb or section of the tree canopy. It also causes the fruit to grow lopsided and taste bitter and salty.

Unlike canker, greening does not spread by casual contamination of humans and their equipment, or by wind and rain.

Denise Feiber, public information director for the Florida Division of Plant Industry said the insect that spreads the disease had been found in the Delray Beach area in 1998, but no infected trees had been found until now. She said her office has been surveying trees in Florida for the past four years, looking for the disease.

"This is a very very serious disease, but we've been preparing for it for several years" Feiber said.

Tim Gottwald, research leader at the U.S. Horticultural Research Laboratory in Fort Pierce, who presented scientific research on greening at the meeting, said the disease is most prevalent in parts of Asia and Africa and its presence keeps the citrus industry from growing on those continents.

The disease spreads rapidly, he said. It was first found near Sao Paolo, Brazil, 10 years ago and since has spread to 75 neighboring municipalities.

The department may use natural means such as wasps to kill the insects because there is no known pesticide, he said.

Because greening is classified as a biological threat, the FBI will join the hunt for the origins of its arrival. The disease is on a list of 10 plant and 45 foreign animal diseases that have been identified as biological agents or toxins deemed a threat to public health, animal or plant health, or products.

"This is as bad as it gets and we need to do a better job at safeguarding our borders," said Nat Roberts, chairman of the Indian River Citrus League and general manager of the Callery-Judge Grove near Loxahatchee. "We need to stop this stuff from coming into our borders. This is the ugly side of globalization."

The news upset local growers who attended the league meeting.

"I just hope it stays in that area," said George Hamner Jr., president of Indian River Exchange Packers in Vero Beach.

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