Canopy architecture, solar radiation partitioning, and yield performance of a high-density cactus pear (Opuntia ficus-indica) hedgerow system in a semi-arid region

High-density planting systems are a potential strategy for intensifying cactus pear ( Opuntia ficus-indica ) production in semi-arid regions. However, quantitative assessments of canopy architecture, solar radiation interception, and yield dynamics within intensive hedgerows remain limited. This study evaluates the structural and physiological performance of a mature, commercial high-density paired-hedgerow orchard (1,666 trees ha −1 ; 6 × 2 × 0.5 m spacing; north–south orientation) over two consecutive seasons (2024–2025) in Sicily, Italy. Stem area index (SAI), daily photosynthetically active radiation (PAR) distribution across canopy faces, cladode water status, fruit yield, and commercial fruit quality attributes were monitored. In this symmetric hedgerow system, incident solar radiation was evenly partitioned between opposite lateral canopy faces on a daily integrated basis (~50% each), keeping photosynthetically active cladode surfaces well illuminated. Over the two-year period, the orchard sustained average fresh fruit yields exceeding 30 t ha −1 , substantially higher than typical baseline ranges reported in the literature for conventional extensive orchards (12–17 t ha −1 ), while maintaining commercial fruit quality standards (mean fruit weight >120 g; total soluble solids averaging 12.8°Brix). Cladode relative water content (RWC) remained stable (~80%) through flowering and early fruit development, consistent with robust internal water storage buffering. These findings document the structural feasibility and high productivity of intensive cactus pear hedgerows under semi-arid conditions, providing valuable architectural baselines for future comparative trials evaluating multi-density or multi-orientation orchard configurations.