While the citrus industry seeks better solutions to huanglongbing—also called citrus greening—growers can use nutritional programs to help keep greening-infected trees productive as long as possible.
Tearing out infected trees as soon as the disease is detected isn't always the most practical solution, says Fritz Roka, associate professor of agricultural economics at the University of Florida's Southwest Florida Research and Education Center in Immokalee.
"To make roguing work, you have to be very vigilant on scouting," he says. That means starting early and never letting up.
Replanting after tearing out infected trees leaves growers waiting two to three years for young trees to come into production, Roka says.
That was the calculation Maury Boyd, president of McKinnon Corp. in Oakland, made when he first realized his Orange Hammock grove was severely infected with greening.
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In 2006 the decline that he'd initially attributed to hurricane damage was diagnosed as HLB; 70 percent of the grove's young trees and 43 percent of his mature trees were infected.
"I was told then the trees would probably be gone in two to three years," Boyd says. "I didn't buy into the prediction of utter doom."
The tipping point had come and gone before he'd even been aware.
"We couldn't remove the infected trees," he says. "That would've been half the trees in our groves."
Nor would it be a solid long-term solution, with the rest of his trees probably infected but not showing symptoms. That, combined with infected groves on neighboring properties, meant any new trees he planted were certain to pick up the disease in a short time.
A ‘Mediterranean diet’ for trees
Growers in Western states, now on the alert after watching Florida deal with greening, may be able to avoid reaching that tipping point, Boyd says.
He focused on tree nutrition, supplementing a soil fertility program with foliar applications of what's come to be known as the Boyd cocktail full of minerals and other nutrients.
Controlling Asian citrus psyllid, which vectors the disease, also remains essential.
His trees now produce the same fruit yields as before infection, he says.