Effects of Tree Architecture and Shake-and-catch Method on Fruit Removal Efficiency and Damage in Mechanical Harvesting of Apples

Abstract. Almost all of fresh-market apples are picked manually and it is one of the most labor-intensive fruit crops to produce. Due to the declining supply and rising labor cost, fresh-market apple growers are looking for mechanical harvesting solutions. Shake-and-catch is a potential method and has been widely studied. Due to the severe fruit quality issues, this method cannot be widely applied to the harvesting of fresh-market apples. The primary goal of this study was to investigate how tree architectures and the shaker parameters affect fruit removal efficiency and damage and help the growers to find solutions. In this study, a dynamic test system was developed to measure the dynamic response of fruit under certain shaking modes. From the experiment, the physical properties (the length and diameter of limb and twig; the weight of the apple) of tree and the frequency and amplitude of the shaker did affect effectiveness of fruit detachment techniques. The results showed when the amplitude of shaker was 14.3 mm and the frequency was below 15 Hz， the length of the twigs was the most influential factors on the effectiveness of fruit harvesting. With the shaking frequency and amplitude increased, the physical properties‘ influence on fruit harvesting declined. As for shaking frequency and amplitude, the results showed that the amplitude has more significant effect than frequency. Moreover, when the shaking frequency was 14.3 mm and the frequency was 20 Hz, the fruit removal rate can reach 91.43%. This study was aimed at developing an effective mechanical harvester adapting for tall spindle apple trees.