The US Department of Agriculture (USDA) now forecasts the 2013/14 Florida orange crop to come in at 115m boxes, down 5 per cent on its December estimate.
The USDA estimated early-mid orange varieties at 54m, down 2m and Valencia at 61m, down 4m from December.
Industry body Florida Citrus Mutual blamed the decrease on fruit drop caused by citrus greening disease.
'Once again citrus greening rears its ugly head,' said Michael Sparks, executive vice-president an CEO of Florida Citrus Mutual, referencing the bacterial disease spreading throughout Florida's citrus regions. 'We are in an unprecedented situation dealing with this disease and today's crop estimate only emphasises how important it is for research to uncover a solution.'
The USDA makes its initial estimate in October of each year and revises it monthly as the crop takes shape until the end of the season in July. However, the federal government shutdown delayed the initial estimate until Friday 8 Nov.
During the 2012/13 season, Florida produced 133.6m boxes of oranges.
The USDA's estimate of the 2013/14 Florida grapefruit crop is now 16.5m boxes, down 200,000 boxes from December. Specialty fruit is now at 4.4m boxes, also down 200,000.
