Determination of spring rigidity and fruit detachment force with respect to harvesting technique in pistachio nut trees

Abstract

It is necessary to identify some of the tree and fruit features in order to design and select machines that harvest fruit with mechanical methods. This work aims to identify the dynamic tree features of vibration rigid and fruit holding force for harvesting with mechanical methods. The work investigated the vibration rigid for both limb and trunk of pistachio tree. Also, it determined the effect of the diameters of limb and trunk on vibration rigid. The ratio of fruit holding force and fruit weight was identified. The results have shown that the vibration rigid of tree increases with the diameter of limb and trunk. At the implications for Siirt type pistachio, at 10,0 – 15,1 cm stem thickness the stiffness rigidity is 219,38 N/cm and at 30,1 – 35,0 cm it is 416,41 N/cm. At another implication for Uzun type pistachio, at 10,0 – 15,1 cm stem thickness the stiffness rigidity is 240,23 N/cm and at 30,1 – 35,0 cm it is 392,42 N/cm. The FDF/W ratio for Uzun cultivar Pistachio Nut varied from 235, 57 N/g to 57, 27 N/g within one month of tests. The FDF/W ratio for Siirt cultivar Pistachio Nut varied from 346,03 N/g to 52,67 N/g.