Row Orientation and Canopy Position Affect Bud Differentiation, Leaf Area Index and Some Agronomical Traits of a Super High-Density Almond Orchard

Abstract

Super-high density (SHD) is the latest innovation in almond growing. This new cropping system needs to be studied in different climates, soils, latitudes and cultivars in order to promote more efficient and sustainable orchard management. This study shows the effects of two row orientations and different canopy positions on leaf area index (LAI), photosynthetically active radiation (PAR) and biological, phenological and agronomical parameters of a SHD almond orchard. Total bud number and flower bud number were higher for N-S row orientation and more wood buds were detected in top layers. LAI was strongly influenced by layer, but not by row orientation. Row orientation did not affect blooming or ripening phenology. Fruit number per layer was higher for North–South (N-S) row orientation and in middle layers; fruit set showed the opposite trend to flower bud and fruit numbers, achieving higher values for East–West (E-W) row orientation. Hulled fruit yield was not affected by row orientation but by canopy height. N-S oriented rows showed a greater number of empty nuts than E-W, but no differences were found between layers. We concluded that in SHD almond orchards, row orientation is determinant for sustainable crop management.

Two Almond Cultivars Trained in a Super-High Density Orchard Show Different Growth, Yield Efficiencies and Damages by Mechanical Harvesting

“…Shelling percentage was strictly related to the cultivar. Both cultivars showed mean values in line with varietal standards [22]. Cv Tuono's average values stood at around 36%, within the genetic range of 30-40% [7,38,41,54,60].…”

“…These new cropping systems are also called a 'Sustainable and Efficient System'/'Sustainable and Efficient Solutions', or SES, because they make better use of natural resources, such as soil and water, and agronomic inputs, such as fertilizers and phytosanitary treatments, than the open-center orchards [20,21]. The first almond SHD orchard in Italy was planted in Andria (Apulia, southern Italy) in 2013, followed by many Italian companies, which thus gave new life to almond cultivation [22].…”

“…Casanova-Gascon et al [21] studied light interception in an SHD almond orchard compared to an open-center system, which may have problems with "sink leaves" and fruit yield in the SHD system. Maldera et al [22] studied the effects of two different row orientations (N-S and E-W) and canopy position on LAI, PAR, biological, phenological, and agronomic parameters. However, no work has been published yet on the growth, yield, and mechanical efficiencies and quality parameters of different almond cultivars in the SHD system.…”

Scion–Rootstock Combination Determines Pruning Responses in Young Almond Trees

“…The SHD system is also used for other relevant crops, such as olive (Olea europaeae), and is characterized by a greater density of trees per hectare and the complete mechanization of cultivation operations, such as harvesting and pruning, and improving water-use efficiency (Romero-Trigueros et al 2019). Row orientation and tree height are important variants in this system because they affect the outcome in terms of light interception and distribution within the tree canopies (Maldera et al 2021(Maldera et al , 2023. Choice of growing system for tree crops is also based on the plant's physiological response to pruning and to rootstock (Sansavini and Musacchi 1994), and the economic viability of a system essentially relies on the management strategy adopted by the farmer (Jim enez- Brenes et al 2017).…”