NEW YORK - Orange juice futures rose the most in five years after freezing weather damaged crops in Florida and the government said it is investigating a fungicide used on fruit in Brazil.

About 5 percent of Central Florida’s groves were damaged last week as temperatures dropped below freezing, and the weather is forecast to turn cooler next week.

And the Food & Drug Administration said Monday that it will investigate the use of carbendazim on orange trees in Brazil, which supplies about 25 percent of the juice consumed in the United States.

Slumping US inventories have already helped send orange juice futures up almost 39 percent since the end of September. Retail prices as of Dec. 24 were up 7.9 percent from a year earlier at $6.12 a gallon, according to Nielsen data.

Orange juice for March delivery jumped 11 percent to settle at $2.0775 a pound at 2 p.m. yesterday on ICE Futures US in New York, a record for the contract and the highest for a most-active contract since March 2007. The gain was the biggest since October 2006 and left prices up 23 percent this month.

“The market is starting to factor in that maybe there was more to the damage than initially thought,’’ said Michael Smith, president of T&K Futures and Options in Port St. Lucie, Fla.

Prices also rose from the FDA decision to study the fungicide used in Brazil, which could restrict imports, said Judy Ganes-Chase, of J. Ganes Consulting in Katonah, N.Y.

Sterling Smith, of Country Hedging in St. Paul, said the market is nervous about a potential import ban.

A preliminary EPA risk assessment concluded “that consumption of orange juice with carbendazim at the low levels that have been reported does not raise safety concerns.’’

But the FDA is conducting its own testing.