Precision Out West: Invasion Of The Fruit Snatchers

Precision agriculture’s migration to the western U.S. has been sluggish as it has proved difficult to adapt many of the benefits to the fragile specialty crops that dominate the West. Just ask Fran Pierce, who moved west from Michigan after the Washington state legislature funded the Washington State University (WSU) Advanced Technology Initiative. Pierce was charged with directing the resulting Center for Precision Agricultural Systems, and it became immediately clear that he was facing a challenge — when he arrived in 2000 he had no office.

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It wasn’t that Western growers weren’t aware of precision agriculture. In fact, Pierce says that some of the work done by WSU researchers in the mid-1980s on mapping the fertility of potato fields actually predates some of the work done in the Corn Belt. Precision agriculture also has been used extensively in Washington’s wheat fields, and are partly a reason why the non-irrigated wheat fields around Pullman have some of the highest yields in the U.S. at about 150 bushels per acre. But while more of the state’s acreage is devoted to wheat than any other crop, it only ranks fifth in farm-gate value, due to the high value of specialty crops like fruits and vegetables.

The high value of specialty crops is the chief reason that precision agriculture doesn’t play a bigger role. One of the reasons is that very few can be mechanically harvested, says Pierce. And there are other factors as well. Back in 2000, for example, global positioning systems (GPS) weren’t suited to fruit growers’ hilly conditions. However, there’s been a change in the wind over the past several years. It was spurred in part by the hard times that befell the state’s signature crop, apples (see “The Technology Road Map”), and by increasingly fierce competition from abroad. The state’s asparagus crop dropped from 30,000 acres to 10,000 acres, as Peru — with its cheap labor — increased planting exponentially. “Anything you can or jar can go overseas,” says Pierce.

Robotic Orchards

In recent times, growers are increasingly using GPS technology for such tasks as fertility mapping and canopy management, allowing them to pinpoint areas in their fields, orchards, and vineyards which are underperforming. But perhaps the most dramatic innovation in precision agriculture is the use of robots in orchards and vineyards. The technology is still in its infancy, but there may well come a day when a cherry orchard is harvested not by a huge (and expensive) picking crew, but by a robot. (Assuming consumers accept stemless cherries, of course, as researchers have yet to figure out a way to overcome puncture problems from the stems.)

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One company that has made some impressive developments in the use of robots in vineyards is John Deere. It is developing an autonomous orchard tractor that is equipped with a perception system developed in conjunction with Carnegie Mellon University, says Zach Bonefas, a John Deere engineer. The perception system utilizes lasers and cameras mounted on the roll bar of a tractor to perceive the environment around the robot. The laser sends out a beam every 1/2 degree over a 90-degree arc. To help ensure accuracy, Bonefas says the beams are sent out a remarkable 75 times per second. “And every time it reports to us 180 laser points — 75 times per second,” he says. “We get lots and lots of laser points.”

Because engineers know the speed and posture of the robot, they can build a three-dimensional model of the orchard. The robot, which has been in development for three years, may be able to help solve one of the growers’ biggest problems — a shortage of labor. The robot should be able to mow the cover crops in an orchard, as well as do the frequent spraying most growers must do to obtain top quality fruit. In addition, by having a robot do the spraying, there’s no concerns about worker safety. Currently, orchard workers in Washington are subject to monitoring for cholinesterase, a body enzyme needed for nerve function that can be impaired by organophosphate and carbamate pesticides. “If we can get the man out of the environment, it would be a huge victory,” says Bonefas.

Certain orchard designs lend themselves to the use of robots much more efficiently, says Bonefas. Fortunately, the orchards of the past with large trees that aren’t robot-friendly are being ripped out and replaced with trees spaced much more closely together which are often grown on a trellis system. Many growers, in fact, don’t even refer them to trees, but as “fruiting walls.” The one problem Bonefas said might never be overcome is the need for hand labor to harvest certain fresh fruits. “What I’ve learned is that picking apples is an art form, and they’re often picking selectively,” he says. “That’s a tall order for a robot to handle.”

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