Available PAR, Growth and Yield of a Super High-Density Almond Orchard Are Influenced by Different Row Orientations

Abstract

By 2022, the total area of super high-density (SHD) almond orchards worldwide had spread to 14,622 ha. As well as factors such as spacing, and tree architecture, proper row orientation should ensure a more efficient sun exposure, yield and harvesting. This research was conducted in an irrigated SHD almond orchard of cv. Lauranne® Avijor in Andria, Italy, in 2021 and 2022 (at 4th and 5th year from planting, respectively) to gain a deeper understanding on the effects of two row orientations on available Photosynthetic Active Radiation (PAR), Leaf Area Index (LAI), canopy growth, yield and harvesting efficiencies in this new planting system. The east-west row orientation in a SHD almond orchard negatively impacted LAI, canopy growth, yield, fruit quality and yield efficiencies, especially in the second year. The north-south row orientation allowed a better PAR distribution inside the whole canopy than east-west row orientation. This unevenness in PAR distribution inside the whole east-west oriented canopies could represent the driving engine of the effect on growth and yield parameters. Although some quality parameters differed between exposures, they all remained within the standard range of the cultivar. The results provide a scientific basis for improved SHD orchard management, helping to keep them as Sustainable and Efficient Systems (SES).