Florida's $9 billion orange crop, the largest in the world after Brazil's, may not survive an incurable disease that threatens to wipe out citrus groves throughout the United States.
The disease, known as "citrus greening" or huanglongbing, is caused by a bacterium, Candidatus Liberibacter asiaticus
. The bacteria are spread from tree to tree by a tiny insect called the Asian citrus psyllid
, The New York Times reports.
A tree affected by citrus greening may not show symptoms for years. Eventually, however, the leaves turn yellow and fall, while the tree's fruit fails to mature, falling to the ground prematurely before the tree slowly dies.
"We have got a real big problem," Vic Story, a lifelong Florida citrus grower, told The Times. "It's definitely the biggest threat in my lifetime, and I'm 68. This is a tree killer."
There is no known cure for citrus greening (which also affects grapefruit, lemons and other citrus crops), despite the best efforts of numerous research labs. The Candidatus bacteria is so devastating to citrus crops that it was classified as a bioterror weapon in 2003, The New Yorker reports.
Citrus greening isn't the only problem threatening the state's citrus industry, which employs more than 75,000 people. Rainfall in Florida this year has been 40 percent to 70 percent below the average of the past 30 years, Bloomberg reports.
Hurricanes, canker disease (another bacterial infection of citrus fruits), hard freezes and the vagaries of the international orange market, which Brazil dominates, have also battered Florida's citrus industry.
Washington State University has begun a $9-million, five-year project to develop genetically modified psyllids that cannot transmit citrus greening.more