The Effects of Shaking Frequency and Amplitude on the Detachment of Estahban Dried Fig (Ficus carica cv. Sabz)

Abstract

The aim of this study was to determine the most suitable shaking frequency and amplitude for shake harvesting Esfahan's edible fig (Ficus carica cv. Sabz). A hand held limb shaker with adjustable shaking frequency and amplitude was used for this study. A 3x3 factorial experiment with three levels of oscillating frequency (10, 12 and 14 Hz) and three levels of shaking amplitude (20, 32.5 and 45 mm) was conducted to investigate the effects of shaking frequency and amplitude on fruit detachment. Analysis of variance and mean comparison of fruit detachment data showed that the effects of shaking amplitude and shaking frequency on fruit detachment were significant. The percentage of unripe fruit detachment significantly increased at higher levels of shaking amplitude and frequency. Complete ripe fruit detachment (100%) and relatively high unripe fruit detachment (16.9%) was obtained at a shaking amplitude of 45 mm and frequency of 14 Hz, but a shaking amplitude of 45 mm and shaking frequency of 10 Hz with high ripe fruit detachment (93.3%) and acceptable unripe fruit detachment (9.4%) is recommended. Harvesting rate during 5s of shaking was measured which showed that the optimum time needed to harvest a limb is only 4s. Comparison of mean values of cumulative fruit removal of 60% (T60) and 90% (T90) at frequency amplitude combinations indicated that the shaking duration necessary for 60% and 90% fruit removal both followed a decreasing trend by increasing the shaking amplitude and frequency. This study suggests the feasibility of utilizing limb shakers as a practical approach for selective harvesting of ripe fruits.