Extreme vintages affect grape varieties differently: a case study from a cool climate wine region
Eger wine region is located on the northern border of grapevine cultivation zone. In the cool climate, terroir selection is one of the foundations of quality wine making. However, climate change will have a significant impact on these high value-added vineyards. This study presents a case study from 2021 and 2022 with the investigation of three grape varieties (Kadarka, Syrah, Furmint). The experiment was conducted in a steep-sloped vineyard (Nagy-Eged hill) with a southern exposure. In the upper part of the hill (NE-upper), moderate water deficits occur regularly, while in the lower part (NE-lower) this phenomenon is usually not observed. Pre-dawn, stem and midday water potential were monitored during the growing season using a Scholander-type pressure chamber. Climatic data were measured with an automatic weather station. Gas-exchange parameters were measured with a Ciras-1 infrared gas-analyzer. Finally, yield (berry weight, skin weight, seed weight, skin to flesh ratio) and quality parameters of the fruit were also measured at harvest time.
Climatic data show that 2022 was much warmer and drier than 2021.This had a great impact on water potential and gas-exchange of the vines. Different vine varieties responded differently to the same water deficit. This was reflected in physiological parameters as well as in the yield quality and quantity. It seems, that the Kadarka variety is less sensitive to higher VPD than Furmint and Syrah. This is reflected in both stomatal conductance and net photosynthesis. The skin-to-flesh ratio increased significantly for all three varieties in 2022. However, Kadarka variety responded to water deficit with a strong, whereas the Syrah responded moderate increase in skin weight. Furmint, on the other hand, showed the most significant decrease in pulp weight, associated with a small increase in skin weight.
Acknowledgements: This research was funded by Thematic Excellence Program (grant no. TKP2021-NKTA-16).
Issue: ICGWS 2023
1Eszterházy Károly Catholic University, Institute for Viticulture and Enology, Eger Leányka Street 6.
2Eszterházy Károly Catholic University, Department of Environmental Sciences and Landscape Ecology, Eger Leányka Street 6.
3Eszterházy Károly Catholic University, Food and Wine Research Institute, Eger Leányka Street 6.
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water deficit, climate change, Furmint, Kadarka, Syrah, terroir, gas-exchange, yield