WINETECH Technical Yearbook 2020

phenology, a sensitive indicator of climate change. The study tests the hypothesis that the grapevine is responding to climate change through altered phenology, growth and ripening responses, considering that the grapevine’s performance is affected by global environmental parameters de- spite differences on vineyard and site level.

effective adaption to an ever-changing en - vironment. Climatic features that affect key grapevine physiological processes need to be assessed on a finer scale in order to op - timise distribution of a grapevine cultivar in a specific environment, based on grape - vine physiology thresholds in the context of climate change. Matching cultivar and terroir requires cultivar-specific studies, together with knowledge of grapevine reac- tion in terms of growth and ripening when confronted with different climatic/extreme weather conditions. The plant’s reaction to seasonality of environments can be seen in

of climate change, the aim is to match the cultivar growth and ripening response to the climate, for ripening to match the cooler part of the season. Globally, the varietal spectrum will change substantially in future since the suitability for the cultivation of a given cultivar is largely temperature driven. This study proves that the climate is warming/cooling, dependent of area and months, which emphasises the need for more semi-real time climate data that can be used within season for decision making. Frequency

analysis would greatly and effectively guide decision making in this regard. Geostatistical modelling of phenology and grapevine responses using isolated driving factors as inputs, can aid as an in-season monitoring and management tool for better climatic adaptions for the future within farms and regions (www.terraclim.co.za). SUMMARY Seasonal variability is increasing in the context of climate change, thus it is imper- ative to understand the grapevine’s growing environment at all climatic scales to ensure

For more information, contact Tara Southey at tara@sun.ac.za.

WINETECH TECHNICAL YEARBOOK 2020 33