Florida avocado growers worry about devastating disease

Excerpts from an article published in The Packer on 05/29/2009 by Doug Ohlemeier

HOMESTEAD, Fla. — Fearing a new disease could become as devastating as canker and greening are to the state’s citrus industry, Florida avocado grower-shippers are fighting a tiny beetle that spreads a disease that can kill their avocado trees.The laurel wilt fungus, spread by the exotic redbay ambrosia beetle, could wipe out half the state’s avocado crop, scientists warn.The laurel wilt disease has killed redbay trees, which are closely related to avocado trees, throughout the southeastern U.S. as the disease has moved from South Carolina and Georgia into south Florida.

Alan Flinn, administrator of the Florida Avocado Administrative Committee, in mid-May heard an update from University of Florida Institute of Food and Agricultural Sciences scientists who are working on developing repellents.Flinn said a just-completed survey showed no incidences of the beetle in neighboring Broward and Palm Beach counties, counties that are directly north of the south Florida Miami-Dade County avocado growing region.

Earlier surveys detected the beetle as far south as Okeechobee and Indian River counties, within 100 miles of the state’s avocado groves. Surveyors planned to begin surveying for the bug that is as small as President Abraham Lincoln’s nose on a penny during late May, he said. The red bay tree hosts the beetle.Flinn said the news of no positive finds was positive news for the industry.

“This is a very serious threat to our industry,” he said. One of the big concerns involves movement of firewood during a drought into and from Miami-Dade County from northern parts of Florida and Georgia, Flinn said. He said the industry is working to persuade Florida Agriculture Commissioner Charles Bronson to ban firewood movement.Once a tree becomes infected, if it isn’t cut down and burned immediately, Flinn said he’s worried that transporting such wood to landfills could be harmful because the bugs are said to be able to fly up to 20 miles.

Craig Wheeling, president of Brooks Tropicals Inc., chairs the U.S. Department of Agriculture-affiliated avocado administrative committee. Wheeling is also a member of a separate industry-formed committee to secure research funding to battle the bug.“The impending threat of laurel wilt disease bears a striking resemblance to citrus canker, which struck Florida orange and lime growers years ago, causing millions of dollars in damage,” he said. “Having gone through that mess in the early 2000s, we're very concerned when we see the red bay ambrosia beetle’s southern migration.“While we full hardily support the work of the University of Florida in finding ways to stop this pest, we’re also working locally to make the citizens of south Florida aware of the problem and how the migration can be accelerated by transporting firewood or dumping yard waste in southern Miami-Dade County.”