University of Florida researchers say they have developed genetically modified citrus trees that are resistant to greening. It is a significant step against the disease that has devastated Florida's $11 billion citrus industry and is among the worst to hit a US crop.
Researchers developed the trees using a plant gene from the mustard family.
But Jack Payne of the University of Florida's Institute of Food and Agricultural Sciences says the trees still face a regulatory process that will delay their availability by several years.
"I hesitate to use the word, cure, but this is a giant step forward", Payne said.
Greening is spread by a tiny insect called a psyllid. The disease starves trees of nutrients, rendering their fruit unsuitable for sale. Most infected trees eventually die.
Researchers say the trees also show resistance to canker and black spot.