Effect of pre-harvest etephon application on harvest mechanization of uzun and Siirt pistachio varieties

This thesis was conducted in Ahmet Münir Bilgin Facilities of Pistachio Research Institute in 2018 to investigate the effects of pre-harvest ethophone hormone treatments with ripening effects on plants on harvest mechanization of different pistachio (Pistacia vera L.) varieties. Pistachio tree of Uzun and Siirt pistachio varieties planted at 8x8 m spacing and at the age of 40 and yield year were used in experiments. Experiments were conducted in randomized blocks design with 3 replications with a single tree in each replicate. Four different ethophone doses (0, 1000, 3000, 5000 ppm) were applied 15 days ahead of two different harvest periods (light, dark). Harvest was performed with a shoulder-type hooked branch shaker. Manual harvest was also performed to make economic analysis. Phenological observation, cluster abscission rate, fruit breaking resistance, endocarp removal force from the seed, flower bud abscission and leaf abscission rates were determined. Also for fruits, split ratios, split space, endocarp coloring, seed color, endocarp separation, endocarp splitting, 100 endocarped fruit weight, 100 roasted seed weight, 100 red seed coated weight, 100 dry roasted seed weight and 100 seed weight and seed yield were determined. Manual and machine harvests were compared. Applied hormone doses had positive effects on cluster breaking force from the branch and endocarp removal force from the seed, but did not have any significant effects on leaf abscission. The greatest cluster breaking force at both harvest periods was observed in 5000 ppm treatments of Uzun variety and in 3000 ppm treatments in light harvest period and 5000 ppm treatments in dark harvest period of Siirt cultivar. The doses were also prominent for fruit breaking from the clusters. Machine harvest yielded quite fast outcomes as compared to manual harvest. Pomologically, except for fruit endocarp color and split ratios, significant differences were not observed in the other parameters.