Pistachio is a relatively new commercial tree crop in California, with the majority of commercial acreage being planted within the last fifty years. As pistachio trees age, the character of the tree changes--height, canopy width and trunk girth increases. As pistachio orchards age, the efficiency of harvesting operations needs to be re-evaluated, and perhaps adapted to this changing character of aging trees.
We believe that it would be worthwhile to examine different harvesting methods, including the adaption of direct canopy contact harvesters, to improve harvest efficiency. Alternatively, a planned pruning program to decrease tree canopy height may maintain trunk shaking harvester efficiency because trunk shakers are most efficient at removal of the crop remove crop closest to the trunk.
An experimental program was formally begun in 2010. The first step is to experimentally evaluate current commercial trunk shaking harvester performance against that of available experimental harvesters on larger trees. The experimental harvesters currently available are an experimental trunk shaker produced by Erick Nielsen Enterprises Inc. (ENE Inc.) and a prototype canopy contact head harvester being developed in the UC Davis Biological and Agricultural Engineering Department. Our work with these harvesters inother crops suggests that they be included in the current pistachio harvest project. The photo at right (lower) shows UC Davis harvester in operation in olive.
Dr. Louise Ferguson provides an assessment of the progress after Project Year 1 (2011) in this 3-minute video: