A new, free online tool that collates data on 465 different wine grape varieties suited for warmer climates has been released.
Funded by Wine Australia and developed by Peter Clingeleffer and his colleague Hilary Davis from the CSIRO, the Variety Selector Tool contains information on grape phenology, growth traits and fruit composition for 465 varieties grown in a warm inland climate.
It draws together the information and data that Peter has developed over six years across different research projects.
Data from the Variety Selector Tool can be accessed in two ways: by selecting a known variety of interest or, by using the sort function to identify varieties meeting key selection criteria.
Varieties can be selected on the basis of traits such as berry colour, phenology traits, seasonality (from budburst to harvest), leaf area index (as an indicator of vigour) and fruit composition data including juice pH, titratable acidity, the tartrate to malate ratio (as an indicator of acid balance) and for red varieties, total berry anthocyanins.
“Importantly, the tool will enable the wine sector to identify varieties suited for wine production under future climate change scenarios – particularly in warmer climates,” said Peter, an Honorary Fellow with the CSIRO.
“The tool identifies varieties with a short period of growth (seasonality) or smaller canopies to reduce water requirements and inputs for pest and disease control.”
Interestingly, Peter and his team found that based on the results, early ripening varieties generally had better fruit composition for wine production than late ripening varieties – despite harvest under warmer conditions.
“This was an unexpected result.”
How to use the tool – a snapshot of future scenarios
Peter said the study had been conducted in a warm inland climate to help identify varieties with favourable traits that could be expected to perform well under future climate change scenarios. For example:
- The phenology information can be used to identify early and late ripening varieties to extend the season and minimise risks associated with compressed seasons.
- The budburst information can be used to identify late bursting varieties that may provide protection against early spring frosts.
- The leaf area index information can be used to identify varieties with lower water requirements associated with smaller canopies.
- The seasonality information can be used to identify varieties with a shorter period of growth and hence lower water requirements and low inputs for pest and disease control.
- The fruit composition data can be used to identify varieties with optimal fruit composition when grown under hot conditions. (Importantly, the fruit compositional data can be used to identify varieties with poor ripening characteristics that would not be suited to growing under cooler conditions).
- The berry anthocyanin information can be used to identify varieties that will develop high levels of colour under hotter conditions compared to standard varieties.
Peter said while the tool did not directly address the selection of varieties suited to low alcohol wine production, the fruit composition data for each variety could be used to identify those with low sugar levels that have good pH, acid balance and anthocyanin concentrations.
“Conversely, varieties with high acidity at higher sugar levels would not be suited to lower alcohol wine production.”
The tool is available at grapevinevariety.com