Abstract

Chile has become a significant producer of hazelnuts (Corylus avellana L.) due to its favorable conditions for off-season production to meet global market demand. Efficient light interception is crucial for optimizing the hazelnut yield and quality, as it directly influences the plant's photosynthetic capacity. The goal was to assess the impact of intercepted photosynthetically active radiation (PAR) at upper, middle, and lower canopy levels in hazelnut trees grown at different planting densities and the canopy management of yield and quality parameters. The percentage of vain, sucker, double, bug, and healthy hazelnuts, including the number of fruits, total fruit weight, and grams per fruit was evaluated. The upper canopy levels intercepted the highest PAR, significantly enhancing the number and weight of fruits. The lower canopy levels received considerably less PAR, reducing the productivity. Production pruning in dense planting systems (5 x 3 m) improved the light penetration compared to a less dense planting density (5 x 6 m). Strong positive correlations were observed among PAR, fruit weight, and fruit number, emphasizing the importance of the light distribution within the canopy in hazelnut production. Production pruning and optimized planting densities are essential for maximizing light interception, improving yield, and ensuring high-quality hazelnut production.