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Tree Fruit: Improving Production & Harvest Efficiency
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By Dana Faubion, Washington State University
(appeared in American/Western Fruit Grower February 2006 issue)
We have been endeavoring to increase the productivity of the orchard workforce. Our team, funded in part by the Washington Tree Fruit Research Commission, has had great success showing that simple constant motion machines can increase productivity by 30% for common tasks like pruning and thinning. The caveat is that the orchard system has to be a uniform fruiting wall. These fruiting walls, upright or angled canopy, tend to be rather narrow, less than 14 feet in row width, and the canopy width is less than 3 feet. If the canopy gets thicker than 3 feet, the workforce begins to have trouble interacting with the complete canopy.
This summer, Blueline Inc. of Moxee, WA, imported a machine from Spain called an af-5 harvester. The af-5 is a two-deck work platform. Both large decks are essentially independent hydraulic scissor lifts and can elevate up to 7 feet. Each deck is hydraulically adjusted for width as well, and can expand from 6 feet to 11 feet wide. The machine is powered by an Italian diesel 4-cylinder engine and has plenty of power. It has a two-speed transmission and is four-wheel drive. The af-5 has a four-wheel steering system that makes turning the 25-foot monster a snap.
The machine has a simple auto-steer mechanism that mechanically senses the tree trunks to steer straight down the row. This should eliminate the need for a full-time driver (more about that later). Worker safety is accomplished with good initial training and worker restraints for everybody on the platform. The restraint system is an approved hip belt and lanyard that is fastened to a bar running down the center of the machine.
Multi-Tasking
The unique thing about the af-5 is that it can handle bins, so it can be used as a harvest platform. It is designed to go down the row and pick up previously scattered empties. The empties ride on a front fork. The ground crew picks into their bags and dumps into the bins. The bins are moved on the machine with a hydraulic powered chain similar to a packing line. The full bins are off-loaded out the back of the machine.
Blueline planned to have the machine in by Gala harvest. Unfortunately, it was delayed and the machine did not arrive until the end of October. Gregg Marrs, owner of Blueline, graciously let us use the machine to study its performance; unfortunately, harvest was about over. Brad Carpenter of Carpenter Farms in Zillah, WA, was still picking Pink Lady and he had them planted in a fruiting wall type system. Brad agreed to let us try harvesting his apples with the af-5. Pink Lady is a wonderful apple but it bruises easily, and the stems need to be clipped, making it a very slow apple to harvest. It was not an ideal situation to test the af-5 but it would have to do.
We were able to pick with the machine for about 50 hours with a crew of six. We found that two pickers on the ground and two pickers per deck, one deck at 42 inches high and the other deck at 6 feet, allowed access to the whole canopy. The pickers picked into their standard picking bags and just turned around to dump the fruit in the bin.
Af-5 is a complicated machine. There are different stations for both bin and deck movement. Understanding how to optimize the setting and move the bins requires practice. In our conditions, we did not increase the productivity of the six workers over what their performance on ladders would have been. In fact, we decreased it by almost 10%. As hard as we tried to get a performance test of the af-5, I don’t think we did it. The machine needs to be operated by the same crew for a whole year through pruning, training, thinning, and harvest. I think the machine will increase worker productivity dramatically during select color or size picking.
I did not have the opportunity to study bruising but it appeared to be much less with the af-5 (no ladder and no walking with full bags of fruit). This was very apparent one morning when we got started too early and the fruit was still below 32°F, which increases the sensitivity to bruising. The ladder crews were all halted due to bruising in their bins but the af-5-picked bins continued to be acceptable to the bin checkers.
The crews liked the working conditions on the machine. The modified worker restraint system worked very well. One of the crew forgot he had his restraint belt still on and jumped off the deck when it was about 5 feet off the ground. The belt worked well - it prevented him from reaching the ground. He was known from that point on as the Piñata.
The af-5 is a wonderful machine. However, it is big, complex, and costs about $45,000. It will operate well for pruning and thinning. Is there a place for it? I am not sure yet, but I think so.
Dana Faubion is a Washington State University tree fruit Extension agent in Yakima, WA. E-mail questions or comments about this article to faubiond@wsu.edu.
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