By Citrus + Vegetable staff

The U.S. Department of Agriculture has yet to confirm whether suspicious disease symptoms found in a south Florida grove are indeed citrus black spot, caused by Guignardia citricarpa.

Two independent laboratory tests conducted by University of Florida officials have confirmed that the disease is black spot.

But the USDA makes the official determination in disease finds. The agency is expected to release its results shortly.

It appears to have been present for some time in an orange grove near Immokalee in Collier County.

The mature fruit with the symptoms most likely were infected during spring 2009.

Until the USDA issues its determination, Tim Hurner, a multi-county citrus Extension agent based in Highlands County, says groves in the vicinity are being surveyed to determine the extent of the infestation.

Extension and Institute of Food and Agricultural Sciences officials are currentlly developing a battle plan for what some have called "one of the most important fungal diseases of citrus worldwide."

The best season for control of the disease is now through the summer, Hurner wrote in a recent news announcement.

Growers should ramp up to be more watchful for the disease and take action to implement sprays if symptoms are found.

For more information on citrus black spot, download the university's EDIS publication by clicking here.