(Adds USDA orange crop forecasts, other details)
WASHINGTON, June 12 (Reuters) - The U.S. Department of Agriculture announced on Thursday a total of $31.5 million in funding to combat a plant disease that threatens to devastate Florida's $9 billion citrus industry and has driven up the cost of a glass of orange juice.
As many as 70 percent of Florida's citrus trees are believed to be infected by citrus greening disease, or huanglongbing, which is caused by bacteria deposited on trees by an insect called the Asian citrus psyllid.
"The citrus industry and the thousands of jobs it supports are depending on groundbreaking research to neutralize this threat," U.S. Agriculture Secretary Tom Vilsack said in a statement.
In a monthly report on Wednesday USDA showed sharp cuts to Florida's projected output of various citrus fruits, including oranges, grapefruit and tangelos.
The state's 2013/14 orange crop is now forecast at 104.3 million boxes, down 21.5 percent from 133 million in 2012/13. As recently as November it was expected to be 125 million boxes.
Florida produces over 60 percent of the U.S. orange crop. Its struggles pushed orange juice prices to their highest levels in more than two years this spring, and prices are still up about 19 percent for 2014 to date.
The funding from USDA will include $25 million for research and Cooperative Extension Service projects, and another $6.5 million for projects under the wing of a multiagency coordination group set up earlier this year.
Greening is considered one of the most serious citrus diseases in the world and has been found in several countries in Asia, Africa, the Indian subcontinent and the Arabian Peninsula after being discovered in Brazil a decade ago.
Affected trees may show twig dieback, causing reduced productivity within a few years, and fruit can fail to color properly, be misshapen and have a bitter taste.
State authorities first found HLB in south Florida in 2005. Since then it has occurred in all counties with commercial citrus production.
The University of Florida's Institute of Food and Agricultural Sciences estimates lost revenues to the state since 2006 at $4.5 billion.
(Reporting by Ros Krasny; Additional reporting by Barbara Liston in Orlando; Editing by Eric Beech)