Trends in climate parameters related to winegrape production in North Greece and viticultural consequences

Abstract

In this study, dates of vine developmental stages and harvest dates of eight winegrape varieties in two major wine producing regions of North Greece (Kavala and Naoussa) were gathered. Data of the basic developmental stages (budburst, flowering and veraison) for three varieties in Naoussa covered a period of 8 years while harvest dates observations ranged from 13 to 35 years for eight varieties in both regions. In addition, yield as well as berry (sugar and acid concentration) quality attributes were collected and analyzed. Daily observations of maximum (TX) and minimum (TN) air temperature (^oC) and precipitation (mm) were obtained from the Hellenic National Meteorological Service and were used to calculate viticulture-related bioclimatic indices. Trend analysis revealed increasing trends for temperature parameters in the studied areas. Statistically significant advancement, mainly in harvest dates, with different magnitude among regions, was also found. Harvest date was negatively related in most cases to TX. Negative correlations with temperature were also observed for berry must acidity while positive trends were obtained for sugar content, mainly in Kavala, whereas vine-climate correlations were less evident in Naoussa. The results show that suitable climatic thresholds for quality viticulture in the studied areas may be exceeded in the near future requiring the adoption of new cultivation techniques and strategies.