Determining the effects of branch angle with direction on fruit yield and quality in walnut

Daha sonra doldurulacaktırThis doctoral thesis examined the effects of branch angle (narrow: 45°–60°, upright: 80°–90°, wide: 110°–120°) and branch orientation (west, east, south, north) on phenological development, pomological traits, yield components, yield efficiency, and biochemical composition (total oil, protein, and fatty acid profile) of Chandler and Fernette walnut cultivars under the ecological conditions of Pazarcık district, Kahramanmaraş province, over two years (2022 and 2024). The study employed three-way analysis of variance (ANOVA) and Tukey's HSD test for statistical evaluation. Results demonstrated that branch angle had a dominant effect on fruit quality and yield parameters. Narrow-angled branches exhibited superiority in kernel weight (Chandler: 6.33 g, Fernette: 6.10 g), in-shell weight (Chandler: 13.39 g, Fernette: 13.13 g), and fruit number (Chandler: 390.40, Fernette: 125.77), while wide-angled branches were superior in kernel yield (Chandler: 47.59 %, Fernette: 47.40 %), total oil content (Fernette: 54.30 %), and linoleic acid content (Fernette: 60.99 %). Upright branches showed significant disadvantages in fruit set and yield efficiency. Branch orientation had a more selective effect, with north orientation being advantageous for fruit number and palmitic acid content, and south orientation for stearic acid content. Year effect was positive in 2024 due to higher temperature accumulation. Fernette exhibited 3–5 days later phenological development compared to Chandler, providing an advantage against spring frost risk. The biochemical profile confirmed high PUFA content (73–77 %) in both cultivars, indicating nutritional quality. In conclusion, optimization of branch angle and orientation can enhance yield and quality. Narrow angles are recommended for Chandler and wide angles for Fernette. Future research should include long-term trials across diverse ecologies with hormonal and molecular analyses.