Comparison of a Lightweight Experimental Shaker and an Orchard Tractor Mounted Trunk Shaker for Fresh Market Citrus Harvesting

Abstract

A designed lightweight experimental shaker successfully used to collect ornamental oranges has been tested to harvest fresh market citrus. The aim of this study was to evaluate the removal efficiency and operational times of this experimental device compared to an orchard trunk shaker. Three different collecting systems were studied. ‘Caracara’ citrus trees were tested. Removal efficiency, vibration parameters, fruit and tree damages, and fruit quality were measured. A high-speed camera was used to record operational times and determine cumulative removal percentage over vibration time. The canvases on the ground reduced the severe fruit damages but were not useful to protect against light damages. The experimental shaker produced a higher percentage of slightly damaged oranges. No significant differences in removal efficiency were found between the two harvesting systems. However, removal efficiency using the experimental device could be reduced by 40 percent and working time increase by more than 50 percent when access to the main branches was difficult. In agreement with previous results, the curve representing the branch cumulative removal percentage in time followed a sigmoidal pattern. A model was built showing that during the first 5 s more than 50 percent of the fruits were detached.