Efeito da frequência e amplitude de vibração sobre a derriça de frutos de café

Abstract

Quality parameters influence directly the coffee price. However, selective coffee harvesting is frequently associated to good quality of this product. This procedure can be performed by mechanical vibration. Therefore, the study of the frequency and amplitude parameters is important for the design of a specific harvesting machine. The objective of this work was to evaluate the effect of the frequency and amplitude of vibration, the coffee variety and the ripeness condition of the fruits upon the harvesting efficiency. The vibration tests were done in laboratory using an electromagnetic shaker. The tests were done using amplitudes in the range of 3.75 to 7.50 mm and frequencies in the range of 13.33 to 16.67 Hz. Branches of coffee plants of Mundo Novo variety were tested. The highest harvesting efficiency was obtained when using the 26.67 Hz frequency of vibration. The highest harvesting efficiency was obtained when an amplitude of 7.5 mm was used. It was also observed that the number of fruits per stem influences the harvesting efficiency of the coffee fruits of the Mundo Novo variety.