WASHINGTON — The U.S. Department of Agriculture on Dec. 10 forecast 2013-14 U.S. orange production at 7,780,000 tons (179 million boxes), down 2% from its initial forecast in November and down 7% from 8,349,000 tons in 2012-13.

The U.S.D.A. forecast Florida orange production at 5,445,000 tons (121 million 90-lb boxes), down 3% from November and down 9% from 6,013,000 tons in 2012-13. The Florida crop was reduced by early-season dry conditions and ongoing citrus greening, a disease that causes fruit to fall from trees prematurely and reduces fruit size. If realized, the Florida crop would be the smallest since the freeze-reduced crop of 1989-90. Current droppage is projected to be the highest since the 1960-61 season, the U.S.D.A. said.

New York frozen concentrated orange juice futures gained modestly following the U.S.D.A. report.

Florida’s frozen concentrated orange juice yield was forecast at 1.61 gallons per box at 42.0 degrees Brix, up 1% from last season’s final yield of 1.59 gallons, the U.S.D.A. said.