How to use
Wine grape varieties originating from a diverse range of countries and regions were assessed in a project funded by Wine Australia (Enhanced varieties and clones to meet the challenges of climate change and deliver lower alcohol wines, CSP 0902). Assessments were undertaken over four seasons in the Sunraysia region of North West Victoria, a major hot irrigated region. The results demonstrate that there are significant opportunities to broaden the genetic base of varieties available to the Australian industry to enhance its capability to meet the challenges associated with climate change, limited water supply and drought and high alcohol content. Specifically, varieties have been identified with short seasonality to improve water use efficiency; small canopies to minimise transpiration and improve water use efficiency; early and late harvest to extend the season and in the latter case ripen under cooler conditions, optimal pH, titratable acidity and organic acid balance.
A systematic approach was used to phenotype more than 500 varieties and specific clones (i.e. a total of 880 genotypes) in the CSIRO germplasm collection for traits, considered to be important to the Australian wine industry, for climate change adaptability. The study included close monitoring of vine phenology (i.e. budburst, flowering, veraison and harvest date); measurement of key growth characteristics (shoot fruitfulness, leaf area index, berry weight and estimates of yield); measurement of berry composition (total soluble solids, pH, titratable acidity, malic and tartaric acids, yeast assimilable nitrogen, mineral ion concentrations and in red varieties, total anthocyanins and phenolics).
The study described significant, but stable variation in key traits across the varieties driven by variety. These included a difference of six weeks in budburst, a 2-fold difference in seasonality (i.e. budburst to harvest) with harvest spread over a 4 month period, five-fold differences in fruitfulness and LAI, 15-fold differences in berry weight, 10-fold differences in berry mineral ion concentrations and large differences in key measurements of fruit composition (pH, titratable acidity, organic acid composition, yeast assimilable nitrogen and, in red varieties, total anthocyanins and phenolics). The mean data collected in the study over 4 seasons has been used to develop the Variety Selector Tool.
Data on 465 varieties is provided in the Variety Selector Tool which also includes a number of multipurpose, table and dried grape varieties. Varieties in the Selector Tool are listed by their local names (as listed in the CSIRO Collection) and Prime or Cultivar Names, as defined by the Vitis International Variety Catalogue (VIVC) have also been assigned and are noted in the varietal descriptions. Cultivar names are listed when the assigned prime name is a global name for a cluster of varieties derived from a single original embryo and in these cases the Cultivar name provides a more useful way to distinguish varieties. For varieties with multiple clones, the clone identified for inclusion in the tool is also provided. The use of varieties for commercial production in Australia, based on the collection names and Wine Australia Data (NVS 2015 to 2019) has also been noted in the varietal descriptions, with total crush over the 5 years of less than 100 tonnes indicated by the term ‘small quantities’.
Output for a selected variety includes photographs for each variety, descriptor information as outlined above and a full set of data presented as four year means for phenology (days from July 1 for budburst, flowering, veraison and harvest), seasonality (days from budburst to harvest), growth traits including LAI, shoot fruitfulness, berry weight and an estimate of yield and fruit composition including total soluble solids (TSS), pH, titratable acidity (TA), tartaric acid, malic acid, the tartrate to malate ratio, yeast assimilable nitrogen (YAN), potassium concentration (K) and for red varieties, total anthocyanins and total phenolics.
How to use
Information in Variety Selector Tool can be accessed in two ways
- Use the tool to select varieties with a combination of desired traits which are available in the drop-down menus. Information on each trait is also provided with the drop-down menu. Traits used for selection include colour, phenology (budburst, veraison and harvest date, July 1 = day 0), seasonality (days from budburst to harvest), leaf area index and fruit composition (pH, titratable acidity, the tartaric/malic acid ratio, and for red varieties anthocyanins). It is recommended that no more than three traits be selected at any one time.
- Select a variety of interest directly from the selection menu.
For both methods, a summary of the data for the selected variety is presented and a link to photographs provided. Note: the tool does not provide information for different clones.
Specific uses of the tool
- The Variety Selector Tool can be used to identify varieties with favourable traits. 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. It should be noted that early ripening varieties generally had better fruit composition than late ripening varieties.
- the budburst information can be used to identify late bursting varieties which may provide protection against early spring frosts
- 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 than those with longer growth periods
- the leaf area index information can be used to identify varieties with lower water requirements associated with smaller canopies
- the fruit composition data can be used to identify varieties with optimal fruit composition when grown under hot conditions. Furthermore, the fruit compositional data can be used to identify varieties with poor ripening characteristics which 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.