The disease known as citrus greening, which causes fruit to turn bitter and drop from the trees when still unripe, was first detected in Florida in 2005 but this year's losses from the disease are the most extensive yet, they said.
The United States Department of Agriculture has downgraded its crop estimates five months in a row, a move experts called extraordinary.
Orange production this year has already decreased 10 percent from an initial estimate, they said.
"The long and short of it is that the industry that made Florida, that is synonymous with Florida, that is a staple on every American breakfast table, is totally threatened," Sen. Bill Nelson, D-Fla., told The New York Times. "If we don't find a cure, it will eliminate the citrus industry."
Florida is the second-largest producer of orange juice in the world behind Brazil and the industry is reportedly worth $9 billion to the state's economy.
Citrus greening is spread by a tiny insect, the Asian citrus psyllid, which feasts on citrus trees while depositing bacteria that gradually starves trees of nutrients.