Harvesting fresh fruits and vegetables mechanically has always been a goal of forward-thinking agriculturalists. And today we are closer to fulfilling that goal than ever before.
There has been much success over the past 50 years on the fresh side of the ledger since the development of the mechanical tomato harvester mechanized the processing side of the tomato and kept that industry alive in the face of a huge labor crisis. Since then some crops have been almost totally mechanized, such as fresh cut spinach, and many other crops use harvesting aids that have reduced the use of labor or greatly increased the efficiency of labor that is used.
Still the idea of mechanically harvesting a head of lettuce, robotically wrapping it and place packing it in a carton still appears to be an unachievable dream. Or is it?
“We are not that far off,” said Frank Maconachy, the owner of Ramsay Highlander Inc., Gonzales, Calif.
He was not willing to hazard a guess as to how far down the road the complete mechanization of lettuce will be realized but he said the various technologies are out there and are either currently in use or being tested. An engineer by trade, his science sense takes over when he declines to put a timetable on the effort. He said each phase and each separate part of the process needs refinement and testing and tweaking. And the process also needs an industry champion — a company that helps cover the cost of testing and producing the equipment.
Maconachy, who is a Western Growers board member, updated the WG Board at its annual meeting through a presentation to the Food Safety, Science & Technology Committee. He spoke of three emerging technologies focused on reducing the cost and reliance on agricultural labor and gaining production and harvest efficiencies in the field. His own firm is doing work in these areas, but in an interview with WG&S after the meeting, Maconachy said other companies are also making progress. He believes Ramsay Highlander is ahead of the curve but has no problem with produce companies checking out the competition that is out there.
Maconachy said work on an “Auto Thinner,” which utilizes precision cameras to remove unwanted lettuce seedlings, is the furthest along in development. In fact, Ramsay Highlander has such a machine on the market. It was developed over the last several years and an industry champion did step forward last year to take the development to its final stage and ordered a machine. As is typically the case, Ramsay Highlander granted that firm exclusivity for a limited time. Starting this spring, the machine is available for purchase “to anybody who wants to order one,” he said.
The Auto Thinner uses the cameras to identify unhealthy or unwanted seedlings. Those seedlings are then removed through a targeted fertilizer application that “burns” the unwanted plants leaving appropriately spaced lettuce plants to grow to maturity. The machine can be calibrated to accommodate different plant spacing. The “Auto Thinner” currently treats up to 12 acres per eight hour shift, he said, with further refinements being developed to increase the speed.
Maconachy readily admits that developing an automatic thinner has captured the imagination of other manufacturers as well. He believes Ramsay’s effort, which began several years ago, has a leg up on the competition, but he expects other automatic thinners to be introduced to the marketplace over time. Ramsay does hold a patent on the process that it developed and is being used in its equipment.
The so-called Shudder Cutter is the piece of equipment that just may well revolutionize the lettuce industry, according to Maconachy. Working with a company that specializes in development of vision systems for the video game industry has helped Ramsay Highlander advance the concept of a mechanical harvester that uses optic technology to “examine” heads of lettuce in the field. He explained to the committee that the “Shudder Cutter” uses a sophisticated vision system coupled with heat sensing to target iceberg heads in the field. Mechanically the harvesting aid will then cut the head and lift them from the plant base after pneumatically “blowing down” wrapper leaves.
Maconachy said the “Shudder Cutter” is 100 percent accurate in the field. The firm is currently working on increasing the speed from six heads per minute to 10 heads per minute to make it more economically feasible. He said the seed money for development has come from a European manufacturer who will receive sales exclusivity for the resulting harvester in Europe.
The “Shudder Cutter” has also been tested and performs well on broccoli. Other commodities are also feasible. In the future Maconachy sees the “Shudder Cutter” being integrated with BrimaPack mechanized wrapping systems (discussed in the following section) and to develop coring techniques so that it may be used to pack in the field or feed processing operations.
Maconachy said what stands between the current development of the Shudder Cutter and a working prototype is money. “We need an industry champion to work with us on further development.”
He said the system works but to be operational, a grower-shipper is going to want one that can harvest a wide swatch of the field at one time. He said this would require a machine that has six Shudder Cutter modules at about $150,000 a piece. These will be mounted on a harvesting aid with the appropriate cutting instruments and lifting hydraulics, which will result in a cost of about $1.2 million. If you add the wrapping machines as well, the cost gets up into the $1.6-$1.7 million range.
Even so, Maconachy said the return on investment is there if you crunch the numbers on labor costs.
BrimaPak, which is existing technology developed and owned by a European firm, mechanically wraps head lettuce in the field. The “BrimaPak” system reduces the need for labor by mechanizing the wrapping process. After head lettuce is cut, it is placed in cups, and moved to a wrapping mechanism where a continuous film is applied and heat sealed at the base of the head. Maconachy said labor savings are 50 percent and the ROI on this technology is less than two years.
Unlike the Shudder Cutter, Maconachy said there is nothing theoretical about this equipment or its return on investment. The manufacturer has many machines being used throughout Europe. Last year, the BrimaPak machine was field tested in the Salinas Valley and it worked quite admirably.
While Maconachy is as excited as a witch in a broom factory with these emerging technologies, he is also cautious about the continuing effort needed to build a prototype, test it, tweak it and refine it. For example, he said in showing the Shudder Cutter to one large grower-shipper that is currently considering being the industry champion, the grower discussed the food safety aspects of the knife mechanism. In the original prototype Ramsay had attached the cutting device in a particular manner that made it a bit time consuming to remove. The grower said for practical purposes the cutting device had to be more portable for easy removal and cleaning. It has to be cleaned on an ongoing basis each day. “So we went back to the drawing board and came up with a bayonet mount that will allow the knife to be removed and replaced easily. It can be done in 10 minutes during a break.”
Maconachy said that is the process that always has to be used in developing these machines. It is constantly developing on the computer, building in the factory, testing in the field and tweaking. But he has no doubt that progress will continue and mechanical harvesting of fresh lettuce and other crops is in the not too-distant future.
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