A four-person picking crew can have two on the ground or all four on the platform, but each pick into their own tube.
An apple harvest prototype machine that’s part of a national research effort to automate specialty crop production was put to test in Pacific Northwest orchards during the 2011 harvest. The vacuum system apple harvester, designed by Michigan’s DBR Conveyor Concepts, has been tested in eastern U.S. orchards, but its arrival in Washington State at the end of September marked the start of machine’s first trials in large-scale West Coast orchards.
The machine is a combination of machinery fabrication know-how and farmer ingenuity. Phil Brown of Phil Brown Welding in Conklin, Michigan, came up with the original concept. Michigan fruit growers Mike Rasch and Chuck Dietrich joined with Brown to commercialize the harvester under the name DBR Conveyor Concepts.
Both Brown and Rasch demonstrated the harvester in a Washington research orchard during a late-September technology field day sponsored by Washington State University. After the field demonstration, WSU Extension specialist Karen Lewis took charge of the machine, testing it in a variety of Washington orchards.
The harvester is part of the U.S. Department of Agriculture-funded project Comprehensive Automation for Specialty Crops. The Washington Tree Fruit Research Commission is also funding the harvester project. Lewis is evaluating the machine for fruit quality and bruising, along with other attributes, like picker efficiencies. Bruising that could occur from harvesting machines has been a concern of growers. She also hopes to test the machine under nighttime harvest conditions.
A different style apple harvester, developed by Picker Technologies, is under evaluation by the Washington Tree Fruit Research Commission.
After testing in Pennsylvania and Michigan orchards last year, the DBR apple harvester underwent several changes to make it more farmer friendly, Brown said during the field day demonstration. The Washington unit is pulled by a tractor, to save the expense of a self-propelled machine, and runs off the tractor’s PTO hydraulics. The four-worker platform can be adjusted to fit 9- to 14-foot-wide row spacings. Units developed for Michigan have a wider platform reach to accommodate the industry’s wider row spacings of up to 18 feet.
Control levers enable workers to widen or narrow their platform to best reach the fruit. Apples picked are placed in a hose lined with quarter-inch neoprene foam and moved by vacuum to the dry-system decelerator. The patented decelerator is a large wheel with foam wedges that controls and extracts the apples out of the vacuum environment, Rasch said. The maximum apple diameter that can be accommodated by the machine is 4.5 inches.
Apples are gently distributed in the bin by large neoprene foam flaps dubbed “elephant ears” by Penn State researchers, Rasch said. An electric eye moves the bin filler up and down.
Four empty bins on a trailer follow the harvester. Filled bins are discharged onto the ground, with a fresh, empty bin put in its place.
Though special skill isn’t needed to pick and place the apples in the hose inlet, timing of apple placement in the tubes is important, Rasch said. “The singulation [time between each apple] must be coordinated between picks,” he said, adding that three-fourths of a second is needed between each apple to keep them from bumping into each other as they move through the tube. “If you put sixty apples in the tube within ten seconds, you’d have bruising.”
How does the machine compare to traditional ladder and bag picking?
An average picker using a ladder can pick a bin of fruit per hour, which equates to about 40 bins for a crew of four in a ten-hour day. Rasch believes that to make the harvest machine cost effective, the four-person crew must pick a bin every ten minutes, a speed he considers doable because ladders, picking bags, and walking to and from the bin are all eliminated. That would be six bins an hour or 60 bins in a ten-hour day.
Only 1.3 seconds are needed to pick an apple and bring it to the tube inlet, so picking efficiency could be faster than six bins per hour, he said. “The speed of the machine will always be as fast as your slowest worker on the crew.”
The harvester machine will change how crew supervisors monitor the quality of the apples being picked by the workers. Supervisors will need to use their eyes and ears, watching for spurs on the ground and listening as pickers are in action, Rasch said.
“But by watching the pickers and checking fruit in the bin, there are some checks and balances.”
Rasch added that they are in the process of adding sorting technology to the harvester, which would add field sorting of fruit.
Once harvest is over, the picking apparatus can be replaced with a regular platform, and the machine used for pruning, limb tying, thinning, and other orchard chores, explains Brown, adding that four workers can be situated on each side.
“Basically, it’s a year-round machine,” Brown said. “That makes it real versatile and gives it a quick payback.” A price tag hasn’t been put on the apple harvest machine yet, but Brown believes that units will retail for less than $100,000.