2017 ASHS Annual Conference

Sweet cherry (Prunus avium L.) remains among the most labor-intensive temperate tree fruit crops, requiring large crews of skilled labor for harvest and pruning. Indeed, regional growers associations in the U.S. have identified labor shortages as their highest concern. As new sweet cherry orchards are planted, growers must consider the system precocity and productivity, the fundamentals of orchard profitability. Yet equally important is orchard labor efficiency and its potential to incorporate mechanization and/or automation. The tree fruit physiology team at Washington State University has been refining the high efficiency orchard systems that are sustainable, consistently productive, and yield superlative fruit. Clearly, compact, planar architectures will be essential where the entire canopy is readily accessible. There is much interest in the Upright Fruiting Offshoots (UFO) architecture due to its planar nature and the simplicity of pruning and training. In our trials, hand harvest efficiency was 72% greater in the UFO system compared with traditional, multi-leader systems. In addition, we have demonstrated the potential to mechanically prune vertically-trained UFO orchards. Despite requiring three passes per tree (hedging the east and west sides + topping), mechanical pruning was ca. 20 times more efficient (time/tree) than hand pruning. In addition, we have documented no negative effects of full mechanical pruning on fruit yield and quality in the UFO system. Our partnership with agricultural engineers into novel harvest technologies has revealed great potential to harvest stem-free sweet cherries with excellent quality and efficiencies that are 50-fold greater than hand harvest. We are developing fully mechanical harvest systems as well as mechanical-assist systems that function in a variety of architectures. The successful development of any high efficiency orchard system will depend upon addressing the total system with research at the intersection of biology and technology being key. This presentation will summarize a more than decade-long collaboration toward the development of high efficiency sweet cherry production systems and the vision we have for orchards of the future.