An abscission spray that leaves immature fruit on the tree promises to shake up mechanical harvesting in Florida’s citrus crop.
Meanwhile, Southern blueberry growers aiming for the fresh market are taking notice of mechanical harvesters for their fruit. Machine improvements and firmer-fleshed berry varieties from breeding programs may help tip the balance.
But industry representatives say that still-high fruit prices for both crops provide less incentive to switch from hand-harvesting. At the same time, ongoing concerns about labor availability keep interest high in mechanical harvesters.
‘A remarkably selective’ compound
Florida citrus growers found sufficient harvest workers this year, but labor costs remained at near-record highs, says Jackie Burns, interim director of the University of Florida’s Citrus Research and Education Center in Lake Alfred. Cost is the industry’s driving force behind mechanical harvesting, she says.
No more than 10 percent of the state’s total citrus acreage now is machine-harvested, Burns says. The advent of an abscission agent to loosen mature fruit but leave the rest could change those figures dramatically.
She and other researchers have developed “a remarkably selective” abscission compound, CMNP, that may receive an experimental use permit in a year or two for limited application.
“Abscission is not necessarily the silver bullet, but it is the next big step,” says Paul Meador, president of Everglades Harvesting & Hauling Inc. in LaBelle, Fla.
Without it, growers can harvest only part of their crop with machines and must return to hand-picking in May and June to avoid shaking off the next season’s immature fruit, he says.
For now, harvesting machines must be supplemented with hand-gleaning to recover fruit that falls to the ground rather than into trailers. That added labor increases mechanical harvesting’s costs significantly, Meador says.
Fruit prices have remained high enough to support those costs, but any drop in the market may make hand-picking the whole crop more attractive, he says.
Fritz Roka, associate professor of agricultural economics at the University of Florida’s Southwest Research and Education Center in Immokalee, estimates a machine-and-abscission harvesting combination could cost as low as 75 cents per box. Hand-picking runs about $1.80 to $1.90 per box. “That’s a significant difference,” he says.
Without the use of an abscission agent, recovery rates for commercial harvesting machines—75 percent to 80 percent—aren’t yet optimal. “That much [loss] we can’t ignore,” Roka says.