Fruit detachment according to time during olive mechanical harvesting assessed by movement image analysis

In olive mechanical harvesting with a trunk shaker, vibration frequency, vibration time and number of vibrations are the crucial parameters for the proper use of the machine. The objective of the present study was to evaluate olive detachment according to time using video analysis. Olive trees from the 'Villalonga' variety, grown in Moncada (Valencia), were shaken with an orbital Topavi trunk shaker mounted on a fruit tractor. From the shaken trees, 14 high speed video recordings from high vertical branches were selected, 7 shaken at 20 Hz during 3 s (B) and 7 shaken at 15 Hz during 5 s (C), with 1, 2 or 3 consecutive vibrations with a 3 s delay. Due to the branch angle and the location on the tree, only in two cases a second vibration was needed to detach the 100 % of the fruit. In both cases, the non detached fruits were detached just at the beginning of the second vibration. In all the branches, except one, the 80 % of the fruit was detached in less than 1 s, with an average time of 0.77 s. And an average time of 1.28 s for detaching the 100 % of the fruit. No significant differences were found between the times of the two vibration types (B and C). The relation between detachment percentage and time followed a multiplicative curve, y= k.x(a), with an average R-2 of 99.4 %. No significant differences were found between the "K" and "a" coefficients from the two vibration types (B and C). The detachment of the olives from the high vertical branches follows a non linear pattern with a lower detachment time than the total tree vibration time.