When I was younger, I used to enjoy picking a pint or two of huckleberries in the mountains in the summer. But even when you work hard, huckleberry picking doesn’t yield a lot of fruit per day. Picking raspberries goes faster because the fruit is larger and the berries grow more thickly on the plant. And picking apples is faster still, with output measured in bushels rather than pints.
Still, it’s one thing to pick a bag of apples from an old tree by the side of a gravel road. It’s quite another to spend all day in an orchard trying to earn a living climbing ladders and harvesting box after box of fruit.
All agricultural work is both demanding and dangerous, and working in orchards is one of the most difficult tasks in modern agriculture. Indeed, it’s such hard work that a lot of Americans simply can’t or won’t do it, which leads to labor shortages and immigration issues we continue to fail to come to terms with.
It’s interesting to note we’d never considering harvesting grain fields by hand. I live in a small town surrounded by fields of wheat. At the end of the summer, large and complex machines reap the grain in the field, then thresh it, and finally winnow it. The three-step process is automatic, done on-the-fly as the combine harvester rumbles across the wheat field.
Why not use machines to harvest fruit in an orchard? We could free people from the back-breaking tedium of picking fruit by hand, training them instead to operate the machines that could do the heavy labor both more quickly and more safely. Lower-priced produce could then benefit all of us.
The good news is that agricultural engineers across the nation are making real progress toward exactly that goal. In the process, they’ve found it useful to change trees themselves. Here’s the story.
Machines operate most easily in unchanging conditions. Lawn mowers work because grass in a lawn makes up a pretty uniform surface. Mowers can’t cope with truly major bumps or depressions.
One challenge for creating machines that could help us harvest fruit in an orchard is that traditionally fruit trees have all been quite different. They are “bumpy,” you might say, with this particular tree pruned years ago in one way, while that tree over there has a different shape due to different growth and pruning.
So the first step in moving toward the mechanization of orchards has been creating trees that are much more similar to one another. Along the way it’s also been useful to make the trees shorter. After all, there’s no need to have a 22-foot tall apple tree, with its fruit way up off the ground, when a much shorter tree will do.
Another step forward hinged on what I think is a truly clever idea. Instead of letting the trees grow in their usual, three-dimensional structure, the ag engineers had them pruned to keep them growing upward in just two-dimensions. You could say these trees make thin apple “hedges” in an orchard.
With that innovation, the next step is to design mechanical pickers that can move along the thin rows of short trees, reaching out and picking the fruit.
One idea is to use camera sensors to determine where a piece of fruit is, and then power a robotic-arm that can pick it individually. Before you think that’s too fanciful to be true, remember your car was welded together by robotic arms.
Dr. Qin Zhang of Washington State University works on agricultural automation issues, including the goal of mechanically harvesting fruit trees.
“People all over the word are putting great effort into developing mechanical fruit harvesters. I will not be surprised if we see mechanically harvested apples in the stores in 10 years,” he said to me recently.
Although mechanizing agriculture always entails periods of economic adjustment for all concerned, I’ve got to wish Dr. Zhang the best. The equivalent of a combine harvester for fruit would be a labor-saving device that could help a lot of people in several ways, both in the field and in the grocery store.
Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. Follow her on the web at rockdoc.wsu.edu and on Twitter @RockDocWSU. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.