Published: Jan 18, 2011 9:54 PM EST
Updated: Jan 18, 2011 6:54 PM EST

ST. PETERSBURG, Fla. (AP) - Researchers say December's cold weather affected one-third of Florida's early orange crop varieties and nearly half of the mideseason crop.

In a report released Tuesday, researchers from the United States Department of Agriculture found that 12 percent of the oranges surveyed in the northern growing region - slightly north of Orlando - suffered major damage from the cold, the most of any region surveyed.

Researchers checked hundreds of pieces of fruit from groves around the state.

Grapefruit fared well, largely because the fruit has thicker skin and is more cold-resistant.

 Citrus is a $9 billion industry in Florida.

(Copyright 2011 by The Associated Press. All Rights Reserved.)