Özet:

Objective: The aim of this study was to investigate the effects of rehabilitation practices on yield and quality characteristics of Tombul hazelnuts in economically exhausted orchards in the Ordu province. Materials and Methods: This research was conducted over two years, from 2019 to 2020, in three different orchards located in two different districts. In each orchard, parcels were established with an area of 2 decares and 100 hazelnut ‘ocaks’ for rehabilitation activities, and control parcels with the same specifications were also established. While the control parcels were left to the standard practices of the producers, the rehabilitation parcels underwent various procedures throughout the trial period, including soil structure analysis, plant nutrient element analysis, fertilization, agricultural pest control, pruning of damaged and diseased branches, and the removal of basal shoots. Yield and quality parameters were examined in the trial. Results: The yield values in the rehabilitation parcels were significantly higher than those in the control parcels. The increase in yield per plant in the rehabilitation parcels was calculated as 67% in the first year and 60% in the second year compared to the control. Similarly, rehabilitation practices increased the GKAV values by 29.8% in the first year and 53.8% in the second year compared to the control. Despite the fact that the two-year findings indicated differences in fruit weight (2.46 g - 1.98 g), kernel ratio (56.34% - 49.12%), and shell thickness (1.00 mm - 1.03 mm) between rehabilitation and control parcels, the effect of rehabilitation practices on these characteristics was not statistically significant. Likewise, rehabilitation practices numerically increased the oil and protein ratios compared to the control. Conclusion: The results obtained suggest that rehabilitation practices can lead to significant yield increases in orchards with older hazelnut trees, providing substantial contributions to producers and the regional economy. Furthermore, it is believed that rehabilitation practices can have a positive impact on quality by reducing the percentage of defective fruits in hazelnut trees.