A. Rezaei et al, International Journal of Advances in Agricultural Science and Technology, Vol.3 Issue.2, April- 2016, pg. 01-15 ISSN: 2348-1358 Impact Factor: 6.057 © 2016, IJAAST All Rights Reserved, www.ijaast.com 1 Mechanical Harvesting of Wild Almond (Amygdales Scoparia) by a Pneumatic Branch Shaker A. Rezaei 1 , M. Loghavi 2 , S. Kamgar 3 1. Former Graduate Student, Dept. of Biosystems Engineering, Shiraz University, Shiraz, Iran, alirezaei59@yahoo.com 2. Professor, Dept. of Biosystems Engineering, Shiraz University, Shiraz, Iran, loghavi@shirazu.ac.ir 3. Assistant Professor Dept. of Biosystems Engineering, Shiraz University, Shiraz, Iran, skamgar@shirazu.ac.ir Abstract Amygdales Scoparia, a species of wild almond native to the Middle East and South Asia is grown in calcic–rocky mountains of Iran. The conventional method of harvesting this fruit is by hand. For mechanized harvesting, a portable and light weight pneumatic branch-shaker system was designed and fabricated. For determining the effect of amplitude and frequency of vibration on fruit detachment rate an experiment was conducted in Kherameh region which is located in Fars province. The flow of pressurized air and electrical current necessary for operating the system are provided by a set of electric generator and an air compressor on a portable palette. For controlling the frequency of vibration and changing the amplitude of oscillation, the shaker was equipped with a programmable logic controller (PLC) and a pantograph system, respectively. The experiment was conducted by using a factorial design based on a completely randomized design with four replications. The effect of three levels of oscillation amplitude (2, 5 and 8 cm) and three levels of oscillation frequency (8, 12 and 16 Hz) on percent and rate of fruit detachment was investigated during 5 second intervals. The results showed significant effect of frequency and amplitude of oscillation on the percentage of fruit detachment, while their interaction effect was not significant. The cumulative graphs of fruit detachment rates showed that the maximum fruit detachment is obtained at all amplitudes and frequencies of oscillation during the first 5 seconds from the beginning of harvesting. Finally, the 5 cm amplitude and frequency of 16 Hz was suggested as the most suitable amplitude and frequency of oscillation with 90% fruit detachment during 5 seconds oscillation. Comparing hand and mechanical harvesting showed the harvesting rates of 4.91 and 14.7 (tree/minute), respectively. Key words: Tree harvesting, Oscillation frequency, Oscillation amplitude, Fruit detachment rate