Evaluation of Shake-and-Catch Methods on Harvesting of Tall Spindle Apples

Abstract

HighlightsBoth frequency and amplitude were influencing factors in analyzing the fruit removal efficiency and fruit damage.This research focused on tall spindle ‘Fuji’ apple trees, which enriched the study of the variety and architecture resources of apple trees.The advice for shake-and-catch harvesting was based on the analysis of amplitude and frequency from the perspective of energy consumption.Abstract. Almost all fresh-market apples are picked manually, and these apples rank among the most labor-intensive fruit crops to produce. Due to declining labor supply and rising labor costs, fresh-market apple growers are seeking mechanical harvesting solutions. Shake-and-catch is a potential method that has been well studied. However, because of fruit damage, this method cannot be widely used for fresh-market apples. The primary goal of this study was to investigate how the physical properties of the fruit tree and the shaker parameters affect fruit removal efficiency and fruit damage in an effort to help growers find solutions to the above-mentioned issues. A test system was developed, and its performance was evaluated in certain shaking modes. Based on the experimental results, the physical properties of the tree (length and diameter of limb, length and diameter of twig, and apple weight) and the frequency and amplitude of the shaker influenced the effectiveness of fruit detachment. When the amplitude of the shaker was 14.3 mm and the frequency was less than 15 Hz, the length of the twig had the greatest effect on fruit harvesting. However, with increasing frequency and amplitude, the effect of tree properties on fruit harvesting declined, and amplitude had a more significant effect on fruit harvesting than frequency. Moreover, the fruit removal rate reached 91.43% when the amplitude was 14.3 mm and the frequency was 20 Hz. The results of this study contribute to the development of an effective mechanical harvester that is adapted to tall spindle apple trees. Keywords: Amplitude, Apple fresh market, Frequency, Physical properties, Shake-and-catch, Tall spindle.