A disease called greening has infected citrus trees, killing citrus groves and lowering the production of Florida’s No. 1 cash crop.
The U.S. Department of Agriculture released a report April 10 predicting Florida will produce 1 million boxes of Valencia oranges fewer than in March. There are 231 oranges packaged in each box.
The decrease in the Valencia variety made up the bulk of a 1 percent orange decline this month.
“Anybody who drives down the middle of the state on Highway 27 will soon learn that the canopies are very thin. We have an enormous amount of unwanted fruit drop,” said Jackie Burns, director of the Citrus Research and Education Center, which is part of UF’s Institute of Food and Agricultural Sciences.
Greening first affected a citrus crop in Florida in 2005. Now, the disease has spread across the state.
“When we first saw it, it was just a gradual progression. You know, maybe 1 percent of the trees in a grove might be infected, but now all the citrus-growing regions of Florida are infected,” said Calvin Arnold, U.S. Horticultural Research Laboratory director.
There is no cure for citrus greening. It is spread by psyllids, small bugs that carry the bacteria said to cause the fruit malfunction. The damage pervades tree roots, causing less fruits to grow over time.
Citrus psyllid researchers such as IFAS Research Entomologist Michael Rogers are searching for a cure. Rogers said psyllid numbers have dramatically decreased since scouting efforts began. Citrus Health Management Areas, part of IFAS, maps out psyllid populations in the state.
Grove caretaking can have an impact on psyllid populations, said Jim Snively, vice president of the state’s third-largest citrus grower, Southern Gardens. The grove has suffered from the financial impact of greening.
“Over the last seven years we have removed over 600,000 trees, which is about 25 percent of our total tree population.”
He figured that came down to over a $10 million loss.
But Snively has a new cause for hope. Researchers introduced an experimental combative compound for the greening bacteria at a conference in early February.
“There are some real promising results out there and some real promising tools, I think, that will develop over the next two years that I hope will put us in a better position,” Burns said.
Sarah Brand and Charmaine Miller wrote this story online.