R.B. Elkins, J.M. Meyers, V. Duraj, J.A. Miles, D.J. Tejeda, E.J. Mitcham, W.V. Biasi, L. Asín, J. Abreu
A self-propelled platform (Argiles AF-8) was tested in four mature ‘Bartlett’ pear orchards in Lake County, California in 2006 and 2007 to address productivity, post-harvest quality, ergonomics and worker satisfaction. Orchard characteristics included densities of 640-834 trees/ha, heights of 5.7-4.3 m, and trunk-to-canopy edge distances of 1.7-0.7 m. This contrasts with example orchards from Portugal and Spain with 1600 and 2300 trees/ha, 3 m and 2.5 m heights, and 0.9 and 0.5 m trunk-to-canopy edge distances, respectively. Results from a 12-day machine trial using a somewhat atypical hourly-paid crew (majority female, average age 43 years and 15 years orchard experience) were compared to the norm of a typical piece-rate crew harvesting from 5.3 m ladders (100% male, average age 27 years and 4 years orchard experience). Platform productivity, expressed in 500 kg bins/worker/day, averaged 1.8 for selective (partial tree) harvest and 3.4 for complete fruit removal (“stripping”) compared to the ladder crew’s 3.5 and 5.5, respectively. Productivity was highest where the canopy was narrowest (0.7 m). Platform-harvested fruit had 57% fewer stem punctures. 2007 platform modifications included night-time lights, overhead shading, increased vertical reach, and re-configured conveyors to target a productivity goal of 6 bins/worker/day. Productivity for the hourly-paid mixed-gender crew over 5 days and 2 nights was similar to 2006, but increased 75% (3.4 to 5.9) for a 100% male crew paid piece rate, comparable to an average ladder crew. Post-harvest quality was similar to 2006, despite faster picking rate. Worker ergonomics and satisfaction favored the platform both years. Hourly-paid platform crew productivity was comparable to that in Portugal and Spain but California’s short harvest window and 35-70% higher per hectare yields necessitate higher machine productivity. Major barriers to widespread adoption of platforms for harvest in California pear orchards are 1) capital and maintenance costs, 2) orchard renovation expense, 3) fruit sorting challenges and 4) lack of imminent drastic labor shortage. Overhead costs might be mitigated with lower insurance rates, machine use in pruning, fire blight cutting, pheromone tying, night-time harvesting fruit thinning. Further harvest mechanization research is being initiated.
Elkins, R.B., Meyers, J.M., Duraj, V., Miles, J.A., Tejeda, D.J., Mitcham, E.J., Biasi, W.V., Asín, L. and Abreu, J. (2011). COMPARISON OF PLATFORM VERSUS LADDERS FOR HARVEST IN NORTHERN CALIFORNIA PEAR ORCHARD. Acta Hortic. 909, 241-249
DOI: 10.17660/ActaHortic.2011.909.26
Pyrus communis, 'Bartlett' pear, 'Williams' pear, harvest technology, platforms, mechanization, labor, ergonomics, orchard ladders, fruit quality

Acta Horticulturae