BLACK SPOT: Another citrus disease

Highlands County's extension office is notifying growers about a new citrus disease.

The University of Florida says it's caused by guignardia citricarpa, but growers are calling the fungal disease "black spot."

Because it causes fruit to drop early, it's fatal to citrus, according to researchers, and it appears to be the latest economic threat to the citrus industry that will spread across Florida, increasing spraying and production costs, and shrinking harvests.

That's part of the good news, however. The mini-fact sheet, circulated by local citrus agent Tim Hurner, lists three sprays to control the disease, which causes hundreds of orange or red spots on the rind that eventually blacken.

Denise Feiber, a spokeswoman for the Florida Department of Agriculture and Consumer Services, was quoted in Monday's Lakeland Ledger. She said an Immokalee grower found unusual black spotting on his late-season Valencia oranges last month.

That's about 100 miles from Ben Albritton's family groves in Hardee County.

"They are going to be tarping fruit trucks right away, to limit that exposure," said Albritton, who chairs the Florida Citrus Commission.

The disease spreads mostly through wet leaves, which dry and then spread thousands of spores into the air. Fungus lands on fruit in the trees, but can spread from county to county as fruit is moved to processing plants.

"It will be additional cost, additional time," Albritton said. "It's a very dangerous disease."

Black spot has been around for more than 100 years. It was first discovered in Australia in the 1890s, and was found in Brazil in the 1980s.

Local growers don't know much about the disease yet, but Albritton thinks it will affect trees and fruit similarly to canker, which is currently in two of his groves.

"It's a significant challenge," Albritton said. "We're going to have to work though that."

One immediate problem: the disease could cause another ban on sales of fresh Florida citrus fruits in other citrus-producing states, like heavily populated Texas, Arizona and California.

"We had good science to show that was not a need," Albritton said. "Our science proved to be correct."

Albritton emphasized that although canker, greening and now black spot is fatal to fruit, it's not dangerous to humans.

"Not in any way," Albritton said. "It only affects the fruit."