"I applaud the state for doing this," says Ray Royce, executive director of the Highlands County Citrus Growers Association. "We don't want to be a negative impactor on water quality. No one has a greater stake in preserving water quality and quantity (than growers)."
The BMP program helps assure the public that Florida's citrus industry uses the most economical and environmentally friendly practices, he says.
More attention to detail
The changes will require more attention to detail and to documenting inputs and practices, Royce says. That extra work will pay off, however, given the increasing demand for growers to keep detailed records on other concerns.
Records also should explain when on-farm conditions such as shallow root profiles or disease symptoms call for diverging from nutrition recommendations, he says.
Some Ridge growers, while agreeing with the changes overall, view the details with some caution. Ned Hancock, a grower in Avon Park, worries about maximum levels for total nitrogen applications.
Growers have adopted new approaches to combat citrus greening, but the nutrition recommendations in the guidelines appear to tie growers to "an antiquated way of looking at nitrogen," Hancock says. "It's a whole new ball game with greening."
A more nuanced approach that differentiates application methods and timing would take into account the adoption of more efficient uses of fertilizers and plant growth products, he says.
But Obreza—a soil and water science Extension specialist who helped edit the newest recommendations—says the BMP nutrition guidelines allow flexibility.
"It's not prescriptive," he says. "They can put nitrogen on any way they want." Application methods matter less than using only as much nitrogen as the tree can use.
Since greening took hold, the industry has outpaced researchers when it comes to adopting new nutrient management techniques such as foliar applications, Obreza says.
Research on foliar nutrient applications so far isn't sufficient to form recommendations, he says. Anecdotal evidence and theories eventually will give way to solid research data.
With the manual's nitrogen guidelines tied to the university's recommendations, maximum nitrogen levels will be updated as researchers gain more understanding from testing, he says.
That's separate from periodic revisions to the BMP manual itself, a more involved undertaking roughly every five years.