Ecophysiological characterisation of terroir effects on Vitis vinifera L. Chardonnay and pinot noir in south african cool climate regions
Context and purpose of study – Terroir encompasses environmental (climate, geology, soil and topography), genetic (cultivar and clone) and human factors (oenological and viticultural practices). Climate change brings about shifts in the suitability of a region for the growth of specific grapevine cultivars. This study focused on climatic and fruit parameters (berry size, weight, pH, total acidity (TA) and phenolics) to characterise the terroir effect in Vitis vinifera L. cultivars Chardonnay and Pinot Noir vineyards in the Cape South Coast region (Walker Bay and Elgin).
Materials and methods – Three commercial vineyards per variety across Creation Wines (CN), Bosman Adama (BA), Paul Cluver Family Wines (PC) and Paul Wallace Wines (PW) were selected during the 2021/2022 growing season. Daily minimum and maximum temperatures were recorded (micro-climate) and berry reproductive parameters from Eichorn-Lorenz (E-L) stages 32 to 38 were monitored. Additionally anthocyanin content, colour density and total phenolic index were determined for Pinot Noir vineyards. Yield was determined at harvest and pruning weights were taken during the vine’s winter dormancy. Data was analysed using One-way ANOVA at a confidence level of 95%.
Results – Accumulated GDD was between 1188 and 1229°C days in Chardonnay vineyards and between 1220 and 1242°C days in Pinot Noir vineyards. Significant differences in berry reproductive parameters were observed between vineyards throughout the season for both varieties. For Bosman Adama, Chardonnay and Pinot Noir vineyards consistently produced the largest berries until harvest. Sugar concentrations ranged from 20 to 23 °Brix at harvest for all the vineyards and varieties. The ratio of yield to pruning weight varied from 3.2 to 5.0 which could be ascribed to the site, climate, and canopy management. These results suggest that Elgin and Walker Bay terroirs are suitable for the growth of Chardonnay and Pinot Noir.
Issue: ICGWS 2023
1South African Grape and Wine Research Institute (SAGWRI), Department of Viticulture and Oenology, Stellenbosch University, Stellenbosch, South Africa
2Beijing Key Laboratory of Grape Science and Enology, CAS Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
3University of the Chinese Academy of Sciences, Beijing 100049, China
4Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems (M2 S), KU Leuven, B-3001 Leuven, Belgium
5Leuven Plant Institute (LPI), KU Leuven, B-3001 Leuven, Belgium