If you're enjoying a late-summer fruit pie this Labor Day, consider what went into growing and harvesting that fruit. Chances are, it took a lot of human hands to ensure its skin would be perfect and smooth when you bought it.

While machines have replaced human hands for a lot of farm jobs — the harvesting of tomatoes for processing, the cutting of lettuce and spinach, the shaking of almond trees to make the nuts fall to the ground — many fruit, vegetable and nut farmers still rely heavily on people to plant, maintain and harvest their crops.

Machines don't yet exist for these crops because there have been ample people to do the work, and because it's hard to design machines that can cut or pick the fruit or vegetables without squishing or damaging them too much.

But as immigration policy and enforcement have gotten stricter and migration from Mexico and Central America to the U.S. has slowed since 2008, the farm labor supply has gotten tight. Though wages have risen and some farmers have expanded their acreage, some have been forced to leave thousands of dollars worth of fruit or vegetables rotting in their fields because they can't find anyone to pick it. The work is often back-breaking and risky — workers who have to climb ladders to reach cherries, for example, may fall and injure themselves. And so some workers have found better opportunities elsewhere.

All that's created a new push for research and development into mechanization to replace the kinds of jobs that farmers have an increasingly hard time filling.

"There's an urgent need to develop engineering solutions for a lot of fresh-market fruit and vegetable crops," Matthew Whiting, an associate professor and extension specialist at Washington State University who works with the sweet cherry industry, tells The Salt. "The shortage of skilled harvest labor is on every grower's mind."

For Labor Day, we thought we'd round up some of the crops that can't yet be harvested by a machine, but that may be in the future. To be clear, the issue of farm labor is complicated. And machines that could harvest these crops might not necessarily be good for everyone.

Sweet Cherries

These are the soft, sweet cherries we get in bags with the stem attached. And why do they always look so beautiful and plump? Because a human hand carefully picked them.

But there are fewer and fewer willing hands to do that work. And the government has noticed. Of all the producers that dream of mechanical harvesters to ease their labor woes, the sweet cherry growers might be the closest to getting one thanks to research funding. Whiting at WSU says he and others at the university are close to finding a commercial partner for a prototype harvester they've developed that can pick 50 times as many cherries as a human being would in the same time.

Still, there's additional work to be done before this new model is viable: New varieties of cherries suited to the mechanical harvester will have to be bred. Whiting says research is heading in that direction and that in 10 to 12 years, scientists should be able to offer growers a "suite" of new varieties.


As the Huffington Post has reported, asparagus is uniquely labor intensive because the quick-growing plant must be harvested every day of its three-month growing season. Each plant sprouts multiple spears (the part of the plant we eat) a day, which have to be hand-cut every day. So that means workers are cutting 14 hours a day, seven days a week from roughly February to May.

But various mechanical asparagus harvesters are in development, and the government is evaluating them. According to a 2009 U.S. Department of Agriculture report, "If the U.S. asparagus industry is to insure a competitive position, it must substitute technology for labor to lower per unit costs and shift the workforce to value-added employment. Instituting new technologies is imperative for the advancement of the industry now."


Commercial apple picking today requires brawn — workers have to fill buckets all day long with heavy apples and then dump them into bins. And according to a fruit industry trade publication, "The era of fully automated robotic harvesters navigating [apple] orchard rows is still years away."

Whiting says that's because the apple industry and the government have dedicated little funding to research.

That's changing, though. The Washington State Tree Fruit Research Commission is now pursuing more research on mechanical harvesting.

And this year, some commercial apple farmers may be using a vacuum harvester for the first time. Its designers say it saves time, reduces picker fatigue and boost the harvest yield.


California grows about 50 percent of the peppers in the U.S., and lately the California Pepper Commission has been talking more developing mechanical harvesting and varieties bred to be picked by machines.

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