Mobile orchard platforms are a technology utilized in European orchards that responded to a mid-60s apple marketing crisis by planting high density systems with tall, narrow canopies (Oberhofer, 2004; Mitham, 2005).
An orchard picking platform was designed and tested by Penn State agricultural engineers in the late 60s, but it was difficult to maneuver around the large tree canopies common in commercial orchards at the time (Allshouse, 1970).
A need to retool the Pennsylvania fruit industry with innovative technologies was identified in 2005 following a series of grassroots strategic planning sessions among industry and community leaders. The Pennsylvania Ag Innovations Initiative (now called the Specialty Crop Innovations Initiative) was launched (Baugher et al., Compact Fruit, 2006), and grower advisors to a multi-disciplinary research team recommended that a systems approach be developed for retooling orchards with efficient training systems and labor efficient technologies. The advisory group and research team of horticulturists, Ag economists and Ag engineers agreed that the initial phase of the project should be to test an orchard platform prototype versus ladders in orchards trained to tall tree walls. The project cooperators identified a number of reasons for eliminating the use of ladders in orchards, including low labor efficiency, increased injuries and higher insurance premium rates. Preliminary orchard platform trials being conducted at the time in Washington State orchards had demonstrated 30% increases in worker productivity and a significant reduction in worker injuries (Faubion and Lewis, Good Fruit Grower, 2005).
Trials with an orchard platform prototype were conducted in 24 Pennsylvania orchard blocks. Tree architectures included peaches trained to perpendicular V and apples trained to vertical axis. The purpose of taking the orchard platform to as many orchards as possible was two-fold--the research team could evaluate platform efficacy with various modifications of tree training systems and growers would have the opportunity to assess where tree training and plant spacing adjustments should be made for improved adaptation to automation. An added benefit of commercial orchard trials was that growers and employees provided valuable feedback on possible future directions for team research.
Ladder and platform efficiencies were compared in four uniformly randomized trials for each of six labor-intensive orchard tasks. Worker productivity with the moveable platform compared to ladders increased by an average of 35% for peach thinning and pruning and 50% for peach harvest and apple thinning, tree training or pruning. The platform was more efficient than ladders for all tasks (95% level of confidence). Work performance over time generally increased with the orchard platform and remained the same with ladders. Work quality, assessed for fruit thinning operations by counting fruit in upper versus lower canopies and fruit per scaffold following thinning, was similar or improved from the platform compared to ladders. Thinning and harvesting from the platform resulted in significant economic savings ($126 to $282 per acre for the powered prototype). Results for other operations varied depending on tree age and architecture.
On-Going and Future Investigations
A significant obstacle to orchard platform research was the inconsistency in tree architecture and row spacing from one commercial orchard to the next. Trials are now being conducted in the commercial-scale apple orchard systems plantings funded through a NRCS Conservation Innovation Grant (CIG) and a Penn State FREC peach orchard systems trial funded by State Horticultural Association of Pennsylvania (SHAP) and Robert C. Hoffman Foundation grants.
Autonomous orchard platform trials comparing work efficiency in the narrow tree wall systems are being conducted with both diesel and electric platforms. Sensor technologies were added by Carnegie Mellon University engineers collaborating on a Specialty Crop Research Initiative project titled Comprehensive Automation for Specialty Crops. Labor efficiency with platforms compared to ladders increased by 25% to 105%, depending on the nature of the task. Field trials continue with an electric platform modified to accommodate the low-cost harvest assist system.
Prepared by: Tara Baugher, Jim Schupp, Paul Heinemann, Rob Crassweller, Lynn Kime