Shear Tests of Grapevine (Vitis vinifera L.) Canes

In this study, shearing force, energy, strength and specific shearing energy values of the pruned branches of three local grape (Vitis vinifera L.) varieties (Okuzgozu, Bogazkere and Sire) were determined and compared. The aim of the study is to obtain appropriate data for the design of a machine that can be used in shredding vineyard pruning residues. In accordance with this purpose, the shear tests were carried out with three different knife shapes, two of them are serrated type (serrated 1 -knife-edge thick, serrated 2 -knife-edge thin) and flat (knife-edge flat) with five knife edge angles (50 degrees, 60 degrees, 70 degrees, 80 degrees and 90 degrees). The shear tests were made by Instron Universal Materials Testing Machine, Lloyd LRX Plus. According to test results, maximum shearing force, strength and energy values were obtained at knife of serrated 1 (knife-edge thick) type, the lowest average value was observed at serrated 2 type knife as 382.77 N. The shearing force slowly decreased with increasing knife-cutting angle from 0 degrees to 40 degrees. The maximum shearing force was observed at 0 degrees knife cutting angle as 426.90 N. The lowest values were obtained at 30 degrees and 40 degrees cutting angle. However, when all interaction of Duncan test results is considered, maximum shearing force was observed at serrated 1 knife, 10 degrees shearing angle, and the cane of Okuzgozu grape variety as 669 N, the lowest value of cutting force was observed at Flat-edge knife type, 40 degrees cutting angle and the Sire grape variety as 205.50 N.