Rotundone research awarded best student viticulture prize at WineTech

University of Melbourne PhD student Pangzhen Zhang’s work in precision viticulture and Rotundone in Shiraz earned him the best student viticulture poster at the 15th Australian Wine Industry Technical Conference last month.

Pangzhen is in the second year of his PhD studies, with the submitted poster titled ‘Intra-bunch variability of Rotundone concentration in Vitis vinifera cv. Shiraz wine grapes at harvest’.

‘It was an incredible honour to be awarded this prize, in front of so many researchers and industry professionals’, Mr Zhang said.

‘I think perhaps the research we profiled in the paper was considered quite creative, even though what we discussed in this paper was just the bunch studies. We wanted it to also reflect the bigger picture research we are doing in studying vineyard variability using relatively new technology.’

The poster, highlighted the first year results of a two-year project, partly funded by GWRDC, which is studying the effects of environmental and viticulture management practices on Rotundone accumulation in Shiraz grapes.

Though only half of the data had been analysed at this time, Mr Zhang noted in the poster that differences in Rotundone concentration between the different parts of grape bunches may be related to exposure to sunlight and berry temperature.

He also suggests that Rotundone accumulation might also be affected by the distance from berry to vine vegetative organs, such as stems and leaves.

The field experiments were conducted in a commercial Shiraz vineyard at Mount Langi Ghiran in the Grampians wine region and in partnership with the Australian Wine Research Institute and the University of Melbourne who jointly supervised Mr Zhang’s project.

The project used five sampling points in each of the three vineyard zones, which were identified by vine vigour (using plant cell density maps), slope (using digital elevation maps) and soil characteristics (EM38 survey).  The grape bunches, which were collected close to the commercial harvest date, were then divided into four parts: top south, top north, bottom south and bottom north – dependent on the berries position in the bunch and bunch orientation.

The berries were then analysed separately for Rotundone, as well as standard grape parameters, including Brix, pH, TA, total anthocyanins and total phenolics.

Mr Zhang said the results from 2012 showed the ‘top south’ berries had the highest concentration of Rotundone among the four groups, in all three zones.

The ‘bottom north’ berries showed the lowest concentration of Rotundone.

Mr Zhang said the precision viticulture aspect of this research showed it was a great tool for growers to use to discover the variation not only at the vineyard block level but also within vines and even bunches.

‘We did a number of research experiments simultaneously and we are still processing the past season’s data but we hope to have more interesting findings come out of the project in the future’, he said.

IMAGE: University of Melbourne PhD student Pangzhen Zhang, who won the best student viticulture poster at the 15th Australian Wine Industry Technical Conference last month.

For more information contact Dr Liz Waters, GWRDC R&D Program Manager, liz@gwrdc.com.au

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