L. Gene Albrigo, emeritus professor of horticulture at the University of Florid Citrus Research and Education Center in Lake Alfred, cites two possible causes. But he, too, says he believes citrus greening is the main culprit.
Every year, the number of infected trees rises, he says.
“This is the first year we have perhaps reached a critical number of these kinds of trees in enough groves and enough in each grove to see a statistical effect on yield,” he says.
The second possibility is the disease interacting with weather factors. In this scenario, fruit drop would decline in the future.
“I’m not very optimistic about the second being likely because the conditions didn’t seem to be favorable for excessive drop in general,” Albrigo says.
So far, there hasn’t been much growers can do to counter fruit drop.
Albrigo says attempts to use chemicals to reduce natural drop during the pre-harvest period this year were unsuccessful.
“They were probably put on too late,” he says.
Some chemicals, such as the herbicide 2, 4-D, which are labeled for other crops, may be relatively easy to get labeled for citrus, he says.
Ebel says he is not aware of any practical solutions at this point, although he says there’s a slight chance that starting fertilization programs earlier might help.
From an economic standpoint, fruit drop may actually benefit growers, says Tom Spreen, professor emeritus of food and resource economics at the University of Florida, Gainesville.
“It means the prices are going to be stronger than what they would have been,” he says. “When they started reducing the crop [estimate], you could see the cash market prices begin to perk up.”
By the end of the season, “It probably is a wash or maybe some slight benefit,” Spreen says. “I think the growers will probably be OK in terms of returns.”
High drop rate
The Story Cos., a Lake Wales-based grower that owns or manages 6,500 acres, experienced abnormally high drop of early- and mid-season fruit, says vice president Kyle Story.
“It has had a dramatic effect on our overall operations,” he says.
Story estimates that between fruit drop and the smaller size of the fruit remaining on the trees, his company will be down almost 10percent in its early-midseason varieties compared with last year.
However, that may not be all bad news from a profitability standpoint.