To identify which canopy parameters most accurately indicate optimal vine performance and to determine if an accurate and inexpensive tool can be developed to assess vine balance in the field.
For each variety, region and season there is an optimum vine balance (when vegetative growth and fruiting load are in equilibrium) that delivers the best possible fruit quality for a desired wine style. At present, vine balance assessment is often retrospective, time consuming and subjective.
This project will use enhanced technologies (e.g. image analysis and NIR) to develop novel fast and accurate methods, in the form of a smartphone app, for measuring vine balance. Such technologies have already proven effective at measuring canopy attributes such as leaf area index and stem water potential.
The relationship between vine balance and fruit quality will be assessed from data collected across three of the major grape varieties – Chardonnay, Cabernet Sauvignon and Shiraz at six experimental sites across South Australia and New South Wales. In all regions vine balance will be manipulated through different management strategies such as pruning, bunch thinning, shoot and leaf removal, sacrificial canes, irrigation management and the use of rootstocks. Indicator sites within these and other regions will be established to test the transferability of the findings.
An improved understanding of vine balance and the development of new measurement methods will allow growers to refine management options such as irrigation and canopy management, to ensure optimal grape quality, while reducing labour and input costs.