Hand-harvesting requires teams of skilled workers willing to work hours of back-breaking labor, often in high temperatures. Yet the scarcity and expense of labor in recent years has created high demand for innovative, mechanical solutions to help get crops picked, packed, and shipped in record time. In some cases, innovation can be key as to whether or not a commodity is even grown and sold in the United States.
What’s In Use Today
While growers have used various types of mechanical seeders and harvesters for centuries, especially for use with grains or hardy vegetables like corn, this has not been the case with highly perishable or fragile fresh produce. Yet despite the tedium of hand-picking, the fresh produce industry has been slower to accept automation—though machines are in use for some crops, ranging from berries and grapes to olives and onions.
Today’s mechanized harvesters represent an amalgamation of both old and new technology. The “shake-and-catch” method, which predates World War I, is still in use—like in Washington state’s booming berry industry. According to Dr. Manoj Karkee, an assistant professor at Washington State University, this method vibrates the fruit loose, causing it to fall onto a catching frame.
The mechanical grape harvester is the combination of shake-and-catch technology and an over-the-row approach. Invented in 1964 by J. Roy Orton of Ripley, NY, the machine has continued to evolve: today’s harvesters are four-wheel drive, hydraulically adjustable for various terrains, and convertible to accommodate different trellis formations.
The majority of the fall onion crop is also harvested mechanically, according to Wayne Mininger, executive vice president of the National Onion Association. On the East Coast, Dale Shuknecht, president of Lee Shuknecht & Sons in Elba, NY, builds onion harvesters that can double as potato pickers. The self-propelled machine churns up a wave of soft dirt, causing the onions to drop on a tray where a powerful fan stands the bulbs upright and lops off the tops. The basic model runs about $320,000, and some support equipment (like a tractor for pulling the bin, and a truck to haul the crop) is required.
Perhaps the most high-tech harvester in use today is a robotic strawberry picker. Joseph Wickham, president of Robotic Harvesting in California’s Simi Valley, explains, “The robot picks at approximately the same speed (per robot arm) over time as a human. The robot picks one berry every five seconds per arm.” The good news is the robot can have up to eight arms working at the same time. Wickham states it costs several hundred thousand dollars, but is capable of replacing seven people per eight hour shift.
Due to the unique challenges of fresh fruit and vegetables, Karkee says “fresh market harvest is still mostly manual.” Bridging the gap, however, are ‘harvesting aides’—like at Stemilt Growers in Wenatchee, WA, which grows apples, pears, peaches, and cherries. “We use hydraulic platforms which allow for a more efficient harvest and access to assist the conventional ladders that still dominate our industry,” says Roger Pepperl, marketing director.
Hand-harvesting requires teams of skilled workers willing to work hours of back-breaking labor, often in high temperatures. Yet the scarcity and expense of labor in recent years has created high demand for innovative, mechanical solutions to help get crops picked, packed, and shipped in record time. In some cases, innovation can be key as to whether or not a commodity is even grown and sold in the United States.
What’s In Use Today
While growers have used various types of mechanical seeders and harvesters for centuries, especially for use with grains or hardy vegetables like corn, this has not been the case with highly perishable or fragile fresh produce. Yet despite the tedium of hand-picking, the fresh produce industry has been slower to accept automation—though machines are in use for some crops, ranging from berries and grapes to olives and onions.
Today’s mechanized harvesters represent an amalgamation of both old and new technology. The “shake-and-catch” method, which predates World War I, is still in use—like in Washington state’s booming berry industry. According to Dr. Manoj Karkee, an assistant professor at Washington State University, this method vibrates the fruit loose, causing it to fall onto a catching frame.
The mechanical grape harvester is the combination of shake-and-catch technology and an over-the-row approach. Invented in 1964 by J. Roy Orton of Ripley, NY, the machine has continued to evolve: today’s harvesters are four-wheel drive, hydraulically adjustable for various terrains, and convertible to accommodate different trellis formations.
The majority of the fall onion crop is also harvested mechanically, according to Wayne Mininger, executive vice president of the National Onion Association. On the East Coast, Dale Shuknecht, president of Lee Shuknecht & Sons in Elba, NY, builds onion harvesters that can double as potato pickers. The self-propelled machine churns up a wave of soft dirt, causing the onions to drop on a tray where a powerful fan stands the bulbs upright and lops off the tops. The basic model runs about $320,000, and some support equipment (like a tractor for pulling the bin, and a truck to haul the crop) is required.
Perhaps the most high-tech harvester in use today is a robotic strawberry picker. Joseph Wickham, president of Robotic Harvesting in California’s Simi Valley, explains, “The robot picks at approximately the same speed (per robot arm) over time as a human. The robot picks one berry every five seconds per arm.” The good news is the robot can have up to eight arms working at the same time. Wickham states it costs several hundred thousand dollars, but is capable of replacing seven people per eight hour shift.
Due to the unique challenges of fresh fruit and vegetables, Karkee says “fresh market harvest is still mostly manual.” Bridging the gap, however, are ‘harvesting aides’—like at Stemilt Growers in Wenatchee, WA, which grows apples, pears, peaches, and cherries. “We use hydraulic platforms which allow for a more efficient harvest and access to assist the conventional ladders that still dominate our industry,” says Roger Pepperl, marketing director.
Harvesting aides offer more than efficiency by introducing a new measure of safety. In the case of tree fruit, trips up and down ladders are reduced, as the platforms carry supplies. “Some even have a small sorting table on board,” says Todd Fryhover, president of the Washington Apple Commission.
Advantages
The bottom line, of course, is saving time and money. Mechanized harvesting can certainly slash costs and increase returns, and may allow growers to manage more acres—this is especially crucial when labor availability is questionable. The downside is initial investment and training.
Financially speaking, mechanical harvesting can mean the difference between banking the crop and watching it rot. With the onion harvester, Shuknecht points out the advantage of capturing a timely harvest: built for high volume (covering 25 to 30 acres per day) the grower can try to outmaneuver Mother Nature and pick crops ahead of destructive weather.
What’s Coming?
Multiple trials are underway to help growers speed up the process with specialized harvesting equipment for citrus, olives, grapes, and apples, with applications for other crops as well.
Energid Technologies in Cambridge, MA is testing a robotic harvester for the citrus juice industry says the firm’s president, James English. The project is funded by the U.S. Department of Agriculture (USDA) and the prototype is in its third generation. English explains a main goal is to make a harvester economically viable for citrus growers. “It must cost less than half a penny per orange to pick,” he states, with a manufacturer price tag of between $200,000 and $300,000.
Energid’s apparatus is a heavy base with a boom. The base holds cameras, and the boom houses plastic “frog tongues,” which are flexible and inexpensive to replace. The tongues strike the fruit to detach it from the tree. The brain of the harvester uses computer algorithms to identify fruit and position the boom.
Before building, Energid completed an exhaustive study of what others have already tried. Machine visioning and robotic training are new technologies not previously used in the agriculture industry. “It truly is uncharted territory,” English says.
Dr. Louise Ferguson, pomologist at the University of California, Davis is experimenting with a circular brush device mounted on a Bobcat to harvest table olives. The results so far are promising, with no loss in sensory characteristics between the hand- and mechanically-picked olives. In addition, the 80 percent removal rate is less expensive than manual labor.
The California Table Grape Industry is encouraging further research to design “autonomous utility vehicles” that can move through vineyards at low speeds and perform a variety of functions, including “carrying crates of grapes as they are harvested by workers, and autonomously driving to the packing station,” says Dr. Frank Gabler, viticulture research director. “However, this phase of research hasn’t begun yet.”
At Stemilt, Pepperl says, “we’re testing various mechanical assistance harvesters that allow workers to pick apples [and place them] into a tube or onto a belt to increase productivity.” He calls it “the next wave of technology that will help us keep up with the harvest.”
And the strawberry picking robot may be side-stepping into different fields. “We’re expanding the crops that our equipment handles,” Wickham says. “We’re looking at broccoli and cabbage.”
Karkee is looking at how shake-and-catch technology may be modified for the fresh market, but finds two major obstacles: contact with the fragile fruit and the distance it must fall from the tree. Trials involve catching fruit in smaller areas, compared to the large volume of shaking an entire tree. Although research is still in its earliest stages, foams and other materials are being evaluated for a ‘gentle catch.’
What’s Really On The Line
There is a big picture advantage to mechanized harvesting, too. Because the labor market is at best uncertain, Karkee cites the power of technological breakthroughs to sustain the produce industry for the long term. It is this outcome Ferguson is working towards in California’s table olive industry, believing it is critical to survival.
English sees robotics making major in-roads in the future of agriculture, especially if labor resources shrivel up. As far as robots picking oranges, “it’s not one of the hardest problems. It is doable with current technology,” English states. “I’m confident of that.”
