Incubator Initiative: Do viral infection(s) in the Gingin clone of Chardonnay influence vine phenotype, performance and consequent wine quality?
Abstract
The most widely planted clone of Chardonnay in Western Australia (WA) is anecdotally thought to be the Gingin clone, which produces some of WA’s highest quality Chardonnay, despite poor fruit set, millerandage and low yields. It is thought by many growers that these attributes are due to an interaction with one or more grapevine viruses, in particular Grapevine leafroll virus 1 (GLRV1). This project did not conclusively show a detectable difference between small batch wines made with and without virus when assessed by a panel of experts. One expert was able to reliably detect the difference across two sites, but further research is required.
Summary
The interesting question here is whether viral infection of the Gingin Chardonnay clone can influence the vine phenotype, performance and wine quality. Virus infection is not usually thought to be of benefit to berry characteristics, but in this instance, it may be possible that it is contributing to the sought-after unique nature of some high-quality wines, particularly Western Australian Chardonnay.
Understanding whether GLRV1 and/or other viruses are consistently present in the Gingin clone, and how they affect vines, berry characteristics and resulting wines will begin to answer many questions and provide a basis for further research into this phenomenon. The research outcomes from this project align to the Wine Australia Strategic Plan 2015-2020 Priority 2: Increasing competitiveness, in particular Strategy 4: Improving resource management and sustainability (Biosecurity, pest and disease management).
In this project, small batch wine was produced from vines with and without Grapevine leafroll virus 3 (GLRV3), as it was difficult to find enough vines with GLRV1 only in the short timeframe of 12 months. The main question being asked of the experts on the sensory evaluation panel was whether there was a difference in the wines, not whether it was a “good” or “bad” difference. Overall, the experts weren’t able to reliably pick the difference between a wine made with or without virus, although one particular expert was able to pick the difference. This one individual result shows that the difference may in fact be noticeable to an expert and that further research is likely worthwhile. Future research should also include further chemical analysis of wines with and without virus and include other varietals.