In this project, researchers investigated the effect of cane and spur pruning on yield and grape and wine composition of Pinot noir and Chardonnay used for the production of base sparkling wines, in a cool climate area.
The study was conducted over three years (2010-2012) on a Pinot noir and Chardonnay vineyard which was planted in 1989 in Tasmania’s Coal River Valley. Vine spacing was 2.25 m x 1.5 m and the vineyard was VSP trained;
- From winter 2009, half of the vines were spur pruned and the other half cane pruned;
- Canopy assessment occurred three times during the growing season;
- Yield and cluster number were recorded at harvest;
- Wines were made according to a standard protocol.
- 2011 was a cooler vintage than 2010 and 2012 while 2012 was much drier;
- In both cultivars, spur pruning showed much denser canopies that established quicker compared to the canopies of cane pruned vines;
- Pruning had no significant effect on total yield in either cultivar;
- In two seasons, Pinot noir had a higher amount of clusters per vine where spur pruning was applied. Across all three seasons, the clusters were smaller in this treatment. Chardonnay showed a similar trend;
- Pruning did not affect basic fruit analysis – except in the drier year, Chardonnay showed lower total soluble solids and higher pH where vines were spur pruned;
- Cane pruning seemed to negatively impact the low molecular weight phenolics in wine;
- Spur pruning enhanced hydroxycinnamate concentrations, because of the denser canopy. These compounds have an impact on texture and mouthfeel of sparkling wines.
SIGNIFICANCE OF THE STUDY:
Pruning can be used to manipulate hydroxycinnamate concentrations in base sparkling wines, depending on what wine style the winemaker desires. Leaf plucking can also be judiciously applied to alter the canopy density to affect these compounds.