Intercepted Photosynthetically Active Radiation (PAR) and Spatial and Temporal Distribution of Transmitted PAR under High-Density and Super High-Density Olive Orchards

We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and super (SHD) or hedgerow olive system, by measuring PAR transmitted under canopy along transects at increasing distance from tree rows. Transmitted was measured every minute, then cumulated over day season. The frequencies of different levels occurring during were calculated. SHD intercepted significantly but slightly less overall than HD (0.57 ± 0.002 vs. 0.62 0.03 incident above canopy) had much greater spatial variability (0.21 row, up to 0.59 alley center), compared (range: 0.34–0.43). This corresponded daily values, with more shaded positions receiving low values. lower level row SHD, any position HD, implies self-shading lower-canopy layers, despite similar interception. Therefore, knowing does not allow an understanding differences distribution on ground within their possible effects use efficiency (RUE) performance, between architectural systems.