Citrus Black Spot Location and Management

The citrus black spot (CBS) that emerged in Florida in 2010 apparently remains confined to Collier and Hendry counties, except for a single find in Polk County in 2013.

“There’s a quarantine within those two counties (Collier and Hendry),” University of Florida researcher Jeff Rollins said in a Citrus Expo presentation. “The quarantine extends a little bit into Lee County, but only because of the buffer zone.”

“Every year … there has been an expansion of that quarantine zone,” Rollins added. “The disease is moving slowly.”

The fact that the CBS fungus in Florida only reproduces asexually “means that it doesn’t spread in the air by itself,” Rollins said. “It’s not going to move very far on its own. It has to be facilitated. And a lot of that facilitation may be coming from moving of debris and infected plant material from one area that has the disease to another area that doesn’t have the disease.”

CBS management procedures for growers remain unchanged, he said. Growers should prevent movement of citrus material from the quarantine area. That can be accomplished in part by removing debris from equipment. “And then also (using) the recommended disinfectants when moving equipment from infected areas to uninfected areas,” he added.