As mechanical harvesting increases in most sectors, there is one area where it is in decline. It is yet another victim of the ravages of citrus greening disease.
In Florida, mechanical harvesting has declined by 74 percent as a result of the disease.
"The main reason [for the decline] is greening," said Dave Crumbly, vice president of agricultural services at Florida's Natural Growers, the Lake Wales cooperative juice processor. "The energy [a harvesting machine] takes to remove the fruit is causing a stress on the tree. Greening magnifies the problem."
The Florida citrus industry has been working on developing mechanical harvesters since the 1980s, and some machines began to be widely used by the 1998-99 season, when machines harvested 5,500 orange acres, or 1 percent of the total orange acreage, according to the Florida Department of Citrus.
Orange groves use the harvesting machines exclusively because juice processors purchase 95 percent of Florida oranges, which accounts for about 85 percent of the state's annual commercial citrus harvest. Grapefruit and tangerine growers don't use the machines because they sell a significant portion of those crops on the fresh market, where bruising and other minor damage from machines would make the fruit unmarketable.
Mechanical harvesting peaked at 35,600 acres, almost 8 percent of total orange acreage, in the 2008-09 season, Citrus Department figures show. It fell to 11,347 acres, just 2.6 percent of total orange acreage, in the 2010-11 season and to 9,372 acres, or 2 percent, last season.
Crumbly, who manages harvesting on more than 60,000 member acres in the Florida's Natural cooperative, agreed the company's use of mechanical harvesting fell off in the past two seasons at a rate equivalent to the state figures.
The push for mechanical harvesting declined after several freezes during the decade reduced total citrus land as low as 624,492 acres, including 466,252 orange acres, in 1986, USDA figures show. By the time total commercial acreage returned to 857,687 total acres and 656,598 orange acres in 1996, the push for mechanical harvesting had resumed.
Total citrus acreage currently has fallen to 531,493 acres, including 464,918 orange acres.