Effects of displacement speed and rod vibration frequency on the efficiency of mechanized coffee harvesting

Abstract

Mechanized harvesting of coffee plantations in Minas Gerais has grown rapidly due to its benefits, including increased productivity and reduced labor costs. However, these benefits can only be realized if the harvesting process is properly adjusted to align with the capabilities of the harvesting machine and the specific conditions of the crop field. This study aimed to evaluate the effects of harvester displacement speed and rod vibration frequency on harvesting efficiency and coffee fruit yield. A 3 × 3 factorial design was employed, testing three displacement speeds (600, 800, and 1000 m·h⁻¹) and three vibration frequencies (15, 16.7, and 18.3 Hz). Parameters of the crop were assessed prior to the mechanized harvesting process, including the load of hanging fruits, fruit ripeness, and fallen fruits on the ground. Immediately after the harvest, the following parameters were evaluated: (i) harvesting efficiency, (ii) volume of harvested coffee fruits, and (iii) volume of fallen coffee fruits during mechanized harvesting process. Each treatment combination was tested on 12 plots, and data were analyzed using ANOVA followed by Tukey’s test for pairwise comparisons. Results showed that vibration frequency significantly affected both harvested volume and fruit loss, with notable differences between frequencies. The highest harvesting efficiency was achieved at a displacement speed of 1000 m·h⁻¹, while 600 m·h⁻¹ provided greater consistency across frequencies. These findings highlight the critical role of optimizing speed and vibration parameters to enhance mechanized harvesting efficiency and minimize fruit losses, offering valuable insights for improving coffee production practices globally.