Environmental and yearly influences on four Sicilian grape clones under climate change challenges

Abstract

By the end of this century, up to 90% of traditional viticulture regions in the Mediterranean, including Sicily, are projected to face extinction due to escalating climate challenges such as severe droughts, heatwaves, and unseasonal rains. Islands like Sicily are particularly vulnerable, with climate shifts threatening grape composition, plant physiology, and enological quality. Urgent adaptation strategies, including cultivating heat- and drought-resistant grape varieties, particularly indigenous types, are critical.

This study investigated the influence of environmental and vintage factors on four grape clones; Perricone (RS-7), Nero d’Avola (RS-84), Catarratto (RS-60), and Grillo (RS-297) in three Sicilian vineyards located in the west (W), central (C), and southeast (SE) regions over two growing seasons (2023 and 2024). To understand the influence of the environmental and vintage factors on the four clones, a set of physiological (stem water potential, leaf area and composition) quantitative (total yield, berry, bunch and pruning wood weight), and qualitative traits (TA, TSS, pH) were measured.

Overall, clones exhibited contrasting responses across sites and years. Most clones showed greater vigor and yield in 2023 than in 2024 (p>0.05), except Nero d’Avola, which yielded more in 2024 (2.9 kg/plant vs. 1.4 kg/plant in 2023). Stem water stress varied significantly between clones in both years, with site SE exhibiting greater susceptibility to water stress compared to sites C and W in 2024. Notably, Grillo displayed higher stem water potential (-1.5 MPa at site C vs. -1.1 MPa at site SE). In terms of maturation, site C clones exhibited the lowest TSS in 2023, whereas in 2024, site C recorded the highest TSS.

These findings underscore the significant impact of environmental and vintage factors on grapevine physiology, productivity, and wine quality. Finally, our results highlight the importance of site-specific adaptation strategies and the potential resilience of indigenous grape varieties in mitigating climate change challenges.