New funding reinforces battle against citrus greening

As the Florida citrus industry fights for survival against the devastating effects of the HLB virus, or "greening," a surge of new funding is fueling new research as a key weapon in the battle.

Just a week before Congress finally passed a new farm bill in January that includes $25 million per year for greening-related research and remedial efforts, USDA awarded Florida $20 million that must be spent over the next two years to combat HLB.

In addition, USDA has provided a total of $346,775 in two specialty crop block grants administered by Florida Department of Agriculture and Consumer Services to beat back the short-term effects of greening, such as defoliation, dieback, root decline and fruit drop.

An additional $8 million in greening research was approved last year by the state legislature for this year's budget.

Because of the severity of the threat, 95 percent of the 130 research projects now underway at the Citrus Research Development Foundation in Lake Alfred are aimed specifically at HLB, with another 46 now being considered, according to chief operating officer Harold Browning.

Despite new industry optimism that the ongoing war against HLB can end with a victory, the effects of the disease continue to damage the state's production.

This year, fruit drop and a decline in the general health of trees have continued.

"The fruit drop is as bad as last year's," Browning said. "And some estimates predict it could be worse. A majority of the trees in Florida are now infected. That means that most of the commercial groves in the state have been exposed to the disease and on a grove-wide basis have the [HLB] infection. Within groves, the extent of the infection goes from low numbers up to 100 percent of the trees. So that means we have a huge population of patients that are already sick."

As a result, projected production for this year has been reduced from 125 million boxes to 115 million, Browning said. Last year, Florida produced 133 million boxes.

In response to such continuing declines, the industry has repeatedly emphasized it wants research focused on short-term solutions that can turn the tide against HLB.

Among the most promising current approaches, Browning said, are what he called new "agricultural antibiotics" that have been in development for several years.

"We're at the point now where the most promising groups of materials are ready to be put in the field for tests," Browning said. "But the issues now are showing that they are effective and that they do not cause plant toxicity. Then there's the whole issue of how they would get registered."

In order to be registered for commercial use, the new therapies will have to be approved by U.S. Environmental Protection Agency, U.S. Food and Drug Administration, and USDA. In addition, because there could be overlap with antibiotics used to treat humans, approval could also be required from the Centers for Disease Control.

"So it is an onerous and lengthy process," Browning said, adding that approvals could take several years.

Given that reality, the latest research efforts are focused on nutrition, including micronutrients that can be optimized to fight greening. "The goal is to keep the plants healthy and keep them able to withstand the continuing effects of the disease," Browning said.

Work is also being done on ways to actually reverse the disease. "We're working on both chemical and heat treatments that could lower the bacterial count in infected trees, thereby making them able to perhaps recover or at least stop their continuing decline," Browning said.

Another key focus is developing ways to breed and grow new trees that are resistant to HLB.

"That's important because the existing inventory of trees will not last forever," Browning said.

"And indications are they are now declining more and more. So we're putting a lot of effort in trying to put together a new management system, if you will, for trees that would allow growers to plant with confidence that they will reach productive age and maturity without becoming infected."

Michael W. Sparks, CEO and executive vice president of Florida Citrus Mutual, said he and growers are very encouraged by the new funding and research.

"I'm very optimistic that we'll be able to continue to hire the best and brightest researchers - not just in Florida or the U.S., but from around the world - so I believe we will whip HLB," Sparks said. "I'm also very pleased that much of the current research is focused on short-term solutions so we can keep existing trees productive, while knowing that new trees need to be planted and new varieties are on the way through things like root stock research."

Browning said that he, too, is confident the long battle against greening will be won.

"I try never to indicate otherwise, particularly when I'm looking at the longer term," he said.

"We will continue to make new discoveries and continue to develop new tools. But the concern is how far down we go before the corner is turned. That's really the issue. But some of the therapies we're now looking at would have a profound impact in terms of stabilizing the industry and allowing growers to think about more things than just keeping their current trees alive."