Long-term effects of agrivoltaics on yield and fruit quality performance of bi-color (blush) pears

Abstract

This four-year study investigated the long-term impacts of fixed (non-movable) agrivoltaic systems on the productivity and fruit quality of the Australian blush pear ‘ANP-0118′ in a high-solar radiation environment in Victoria, Australia. Here we show for the first time that fixed-orientation, agrivoltaics significantly alter yield and quality of blush pears over four years. Trees were grown under three treatments: an unshaded control, solar panels tilted at 45° to the west (45°W), and solar panels tilted 5° to the west (5°W). The 45°W and 5°W arrays intercepted 40 % and 46 % of incoming radiation, respectively. Across four seasons (2021–22 to 2024–25), cumulative yields reached 137 t ha⁻¹ in the control but declined to 89 and 77 t ha⁻¹ in 45°W and 5°W treatments, respectively. The four-year average yield in control trees was 34 t ha-1, followed by 45°W (22 t ha-1) and 5°W (19 t ha-1). However, higher yields in control trees were also associated with an increased year-to-year coefficient of variation (32 %) compared to 45°W (19 %) and 5°W (12 %). Blush coverage decreased by 15.4 % (5°W) and 13.4 % (45°W) relative to the control, while green background increased by 21.6 % and 18.3 %, respectively. Soluble solids content also declined under shading, but flesh firmness remained unaffected. Notably, sunburn incidence in the hottest season was 7.0 % in the control but ≤ 1.2 % in shaded treatments. Hail damage in 2022–23 and 2023–24 was reduced by up to 18.2 % in the 5°W system. Physiological responses indicated higher trunk growth and improved photosystem II efficiency under shade, with no impacts on tree water status. Model projections suggest that agrivoltaic systems designed with 20–25 % shade factors could limit 10-year yield reductions to approximately 20 %. These findings highlight the trade-offs between energy generation, yield reduction, and quality loss, balanced by protection against sunburn and hail. Fixed agrivoltaics may benefit pear production in high-radiation regions if systems are tailored to cultivar sensitivity and local climate risk.