Trees infected by citrus greening have yellowing leaves and bitter, discolored fruit.
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. [Gallery: Plants in Danger]
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