University of Florida

Citrus Canker News

UF Researchers Hopeful Canker Can Be Managed

Written Jan. 2006.

The fight to eradicate citrus canker from Florida ended last week when federal officials announced they'd stop funding removal of exposed trees, but researchers with the University of Florida's Institute of Food and Agricultural Sciences are confident that in time the disease can be managed to ensure the future viability of the $9.1 billion Florida citrus industry.

The decision was spurred by scientific projections that the bacteria responsible for citrus canker disease had become much more widespread due to Hurricane Wilma in October 2005. The news will shift UF's research priorities, said Jimmy Cheek, UF senior vice president for agriculture and natural resources.

"Up until now, we've had canker research proceeding along several tracks, one oriented toward eradication, others focused on detection, prevention and management practices," Cheek said. "Since eradication will no longer be the strategy, we need to make sure we're putting our resources where they'll do the most good."

Some existing UF canker programs will be enhanced, new options will be explored and time lines will be accelerated, he said.

"We are working closely with growers, as well as state and federal regulatory officials, to make sure their needs are addressed appropriately," Cheek said. "Our overall goal is minimizing the impact canker and other diseases have on Florida's citrus industry."

UF Extension faculty in citrus-producing counties will play a key role in the effort by communicating regularly with growers to obtain feedback and discuss new research developments, he said.

Canker is spread primarily by wind and rain, and causes citrus trees to develop small brown lesions and produce less fruit, said Harold Browning, statewide coordinator for UF citrus programs in teaching, research and Extension. The current canker outbreak, discovered in 1995, was being contained until several hurricanes in 2004 and 2005 spread the bacteria over a much larger area.

UF experts are working with the Florida Department of Agriculture and Consumer Services, the U.S. Department of Agriculture, representatives of other agencies and the citrus industry to develop a statewide canker management plan and deliver its elements to the industry, said Browning, who also directs UF's Citrus Research and Education Center in Lake Alfred.

The management plan will emphasize disease prevention, he said. Top priorities include protecting healthy trees in nurseries and groves, and ensuring proper sanitation during harvest and processing.

"We have been collaborating with citrus researchers in South America for the past thirty years, and we will try some of their canker-suppression strategies," Browning said. "Brazil has a different climate, but their growers have been somewhat successful protecting groves with a combination of windbreaks, copper-based chemical sprays and decontamination procedures for personnel and equipment."

Canker's effect on Florida citrus production for the 2005–2006 growing season won't be known for months, said Tom Spreen, chairman of UF's food and resource economics department. Researchers are still assessing how far Hurricane Wilma spread the disease, and lawmakers must decide whether growers will be allowed to harvest fruit from exposed trees previously slated for destruction.

Spreen and his colleagues were completing a report on the future of Florida's citrus industry when it was announced the eradication program would end. A revised report, updated to address the latest canker developments, will be issued in early March.

"We know there are a number of ways canker could have a negative economic impact on the industry," Spreen said. "Reduced yield and increased production costs are possibilities. There could also be implications for the export market."

For extensive citrus canker information, please see the Citrus Canker section of the Citrus Research and Education Center website.

Adapted from:

UF News: UF researchers hopeful canker can be managed by Tom Nordlie (1/2006).

citrus canker on leaves

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