Study of the viticultural ecosystem of Listán Prieto (cv. País) variety in the coastal range of Chile

Abstract

Empedrado is located in the coastal range of the Maule Valley and represents a distinctive viticultural ecosystem for the País variety. This environment is characterized by granitic soils, strong maritime influence, and heterogeneous topography, conditions that provide contrasting edaphoclimatic conditions. This study aimed to evaluate the ecophysiological responses and berry quality of bush-trained País vines growing across five representative sites in the coastal range during the 2025-26 season. The selected ungrafted vines were over 50 years old, cultivated under dry-farmed conditions and managed by small-scale viticulturists following traditional viticultural knowledge.

The pre-dawn water potential indicated stronger soil water limitation in Sauzal and Melencura compared with Truquilemu and La Quebrada, while stem water potential confirmed higher water stress condition particularly in Sauzal and La Orilla. Stomatal conductance and transpiration were highest in Truquilemu and lowest in Sauzal. The photosynthetic efficiency remained relatively stable among sites, although electron transport rates were greater in Truquilemu, suggesting enhanced physiological activity. The foliar pigments and vegetation indices indicated higher canopy vigor and nitrogen status in Truquilemu and La Quebrada, whereas increased carotenoids in La Orilla suggested stronger photoprotective responses. These eco-physiological differences were reflected in grape maturity: soluble solids were highest in Melencura and Sauzal, while berry weight was greatest but more variable in Sauzal, indicating greater ripening heterogeneity under stronger environmental constraints.

The findings reinforce the importance of eco-physiological monitoring to understand terroir expression in heritage vineyards and support the role of País as a resilient cultivar suited to dryland conditions and climate variability in coastal environments.