Comparative cumulative energy demand analysis of Tall Spindle and Guyot training systems in mountain apple production

In modern apple cultivation, the choice of orchard training system is a critical factor that directly influences yield, fruit quality, resource efficiency, and energy performance, especially in mountainous regions, where topographic constraints increase operational intensity. This study evaluated the energy performance of two orchard training systems in the mountainous region of Northern Italy: the conventional Tall Spindle (TS) and innovative Guyot (GS) systems. Using the Cumulative Energy Demand (CED) framework, the analysis quantified primary energy intensity across a "cradle-to-farm-gate" system boundary, with all inputs normalized to a functional unit of 1 kg of fresh apples. The results show that the Guyot system reduces the total cumulative energy demand by 22.9%, from 1.44 MJ kg⁻¹ for TS to 1.11 MJ kg⁻¹ for GS. This reduction stems primarily from decreased electricity use (-49.5%) and lower energy embodied in machinery (-66.9%) due to the narrow canopy, which minimizes the need for elevated harvesting platforms. However, GS requires greater embodied energy in the trellis infrastructure (+18.4%) owing to its narrowrow design. Despite these gains, both systems remain heavily reliant on non-renewable fossil sources, which account for over 93% of the total demand, with diesel and fertilizers as persistent energy hotspots. The study concluded that architectural redesign toward simplified narrow-canopy structures is a primary lever for improving energy efficiency in mountain orchards, enabling significant energy savings without compromising yield. Therefore, future research and implementation should focus on integrating architectural innovation with precision input management and renewable energy adoption to further enhance resource efficiency and advance sustainable intensification in mountain agriculture