Issue link: https://read.dmtmag.com/i/196125
New Equipment & Technology In-orchard sorting S toring apples is expensive, and storing bad apples is even more so. If you're going to toss out a cull apple, the best time to do it is immediately. Some packers have gone to prestorage sorting in the packing house. But for growers without packing lines who rent or use their own storage for sales later in the season, a different solution would be helpful. Dr. Renfu Lu is working on that solution. In September, Lu and his team of USDA Agricultural Research Service agricultural engineers working at Michigan State University demonstrated their prototype mobile in-orchard harvesting and sorting machine in a block of Gala apples in Brett Anderson's orchard near Sparta, Michigan. The machine looks very much like the Munckhof Pluk-O-Trak, with its flexing conveyor arms taking in apples as pickers deposit them. Two workers riding on platforms pick high apples and two walking on the ground pick low apples. That's how the apples get to the sorting device. The sorting module looking like those "magic boxes" on packing house lines where apples are photographed multiple times from many angles and their color, size, and external defects identified. And it is. A computer keeps track of each singulated apple as it continues its path toward a bin reserved for others like itself—in this case, fresh market quality apples, processing apples, or juice apples. by Richard Lehnert This machine also has a novel bin-filling device Lu said was designed in-house by his team of engineers. The key, however, is price. Lu thinks the machine can be manufactured from offthe-shelf parts for less than $30,000, making it practical for smaller growers. The camera itself is cheap, he said, selling for about $150. A laptop-like computer equipped with a microchip and a program dictates the apple parameters—size, color, weight, shape, etc. The computer can be trained. The person running the machine can pick an apple, place it before the camera, and show the computer, "these are the kind of apples I want in the fresh-market bin." A prototype machine divides apples into fresh, processing, and juice grades. More culls, more benefit "The higher the percentage of culls, the more the economics favor the machine," Lu said. Growers in the Midwest and Northeast have not achieved the high level of fresh market quality apples that growers in the Pacific Northwest have, he said, so the machine may be better suited for them. The machine would be quite useful in orchards where a lot of fruit was damaged by hail, for example, or where color was a problem, and the job was to salvage the good apples for the higher-price market or to eliminate apples that might rot in storage. Development of the sorter has been under way for about three years, Lu said, with some funding from the Michigan Apple Committee. Lu's team includes fel—Dr. Renfu Lu low engineers Drs. Akira Mizushima, Haiyan Cen, and Fernando Mendoza. "In general, processing apple growers do not expect to sell apples in the fresh market," Lu and Mizushima wrote in a paper assessing the costs and benefits of in-field sorting. "With adoption of an in-field presorting system, processing apple growers can sell some fresh apples from the apples that are originally destined for processing," That would be most useful to growers in Pennsylvania, where 70 percent of the apples go for processing, and least useful in Washington, where only 16 percent go to processing. In Michigan, 65 percent go to processing, 55 percent in California, and 47 percent in New York. "Reducing the cost, that was the big concern," Lu said about designing the harvester/sorter. "We have a simple design using generic components. The sorter can handle six to eight apples per second, which is fast enough for a crew." "Reducing the cost, that was the big concern." 20 NOVEMBER 2013 Good Fruit Grower