A long-term research project to determine which phylloxera-tolerant grapevine rootstock performs best for Mornington Peninsula Pinot Noir will soon undergo the ultimate taste test.
Now in its seventh year, the project – a collaboration between a number of organisations and the Greater Victoria Regional Program – is about to embark on the all-important winemaking component.
‘It’s an exciting moment where we begin to determine whether those consistently productive rootstocks we have identified are most suited to produce quality pinot on the Mornington Peninsula’, said Tyson Lewis, who chairs the technical committee of Mornington Peninsula Wine, the driving force behind the project.
However, there will be no rushing this critical element – with this phase of the project contributing to at least a five-year data set.
Since 2014, the Mornington Peninsula Pinot Noir Rootstock Trial has been comparing 14 different types of rootstocks on the physiological performance of Pinot Noir scion in two commercial vineyards five kilometres apart in the Mornington Peninsula wine region. One vineyard is located in a warmer northern area, while the other sits in a cooler, more elevated location.
At both vineyards, the scions of Vitis. vinifera L. cv Pinot Noir (clone MV6) have been grafted onto 14 rootstocks with each replicate being 3 panels. Grapevines have also been planted on their own roots as a control.
To date, the research team has measured plant phenology, physiology and soil parameters, including the time of flowering and veraison, chlorophyll content, leaf area index, pruning mass, petiole nutrients and soil moisture at the three key stages of grapevine growth – flowering, veraison and harvest.
Preliminary data in the 2018–19 vintage showed clear differences in the timing of flowering, canopy size and presence of plant nutrients. In the 2020 vintage, most rootstocks showed faster veraison progress compared to own roots. Merbein 5489 had the highest percentage of colour change, which was consistent with findings in the 2019 vintage.
Other preliminary findings in the 2020 vintage included that vines planted to:
- 1103, 5BB Kober, Schwarzman, 5C Teleki, Merbein 6262, C20, C113 and C114 showed clearly faster cap fall than own roots
- Merbein 5489 and Merbein 5512 showed slightly slower cap fall
- 101-14 and C29 show similar progress of flowering as control
- Merbein 5489 and Merbein 5512 in both vineyards showed lower K (potassium) deficiency in both vintages (2019 and 2020), and
- in both vintages, rootstocks with high petiole K concentrations tended to show high pruning mass, except 1103 Paulsen, 3309C and C20. This is likely due to the roles of K in catalysing protein synthesis and tolerating water stress.
Two fermentation trials are now set to begin. The first involves researchers from the University of Melbourne, who will be conducting a small-scale laboratory-based fermentation trial; while the second trial will be carried out by Moorooduc Estate, who will conduct sixteen 20–30 kg ferments across the 2 sites (8 per site)
‘The next stage of the project will be to have controlled tastings for the sector’, said Tyson.
The project is a seven-way collaboration between Wine Australia, Wine Victoria, The University of Melbourne, The Australian Wine Research Institute, Mornington Peninsula Wine, Yalumba Nursery and CSIRO.