Submitted to: Applied Engineering in Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/1/2003
Publication Date: 9/1/2003
Citation: PETERSON, D.L., WHITING, M.D., WOLFORD, S.D. FRESH MARKET QUALITY TREE FRUIT HARVESTER, PART I: SWEET CHERRY. APPLIED ENGINEERING IN AGRICULTURE. 2003. 19(5):539-543. Interpretive Summary: Labor shortages and increasing costs of harvesting sweet cherries for the fresh market are putting an economical burden on the cherry industry. In cooperation with the Washington Tree Fruit Research Commission an experimental sweet cherry mechanical harvester was developed, tested, and yielded fruit quality comparable to that obtained by commercial hand harvesting. The experimental harvester also significantly improved harvest labor productivity. Presently, the biggest obstacle to commercialization of this harvesting technique is the fact that tree training systems in commercial orchards are not compatible with this experimental technology.
Technical Abstract: A two unit mechanical harvester was developed to harvest fresh market quality sweet cherries. Units were essentially mirror images. On each unit the harvester-operator used joysticks to position and engaged a rapid displacement actuator (RDA) on main scaffolds to effect fruit removal. Catching conveyors were designed to intercept falling fruit without damage and elevate the fruit to a collecting conveyor. Cushioned catcher pans on each unit were used to seal around the trunk and connect the two units. Main scaffolds were inclined to reduce damage as cherries fell to the catching surface. Ethrel (2-chloroethyl phosphonic acid) was used to reduce the fruit retention force of mature cherries to enable removal without stems or damage. The experimental harvester demonstrated potential for harvesting stemless sweet cherries with not more than 4% more damage than commercial hand harvesting. The catching/collecting system was effective with low damage inflicted to the cherries. Harvest rate down-the-row ranged from 85 to 158 trees/hr with harvester capacity up to 1590 kg/hr (3500 lbs/hr).