Past Projects
- Water-use of grapevines to PRD irrigation at two water levels. A case-study in North-Eastern Victoria
- Soil variability and its influence on the quality and composition of Shiraz grapes and wine
- Australian wine industry 'winners and losers' from climate change
- Precision Viticulture - The role of soil properties and microclimate in driving within-block variability in grape yield and quality
Water-use of grapevines to PRD irrigation at two water levels. A case-study in North-Eastern Victoria
PRD and drip irrigation was applied at two irrigation levels, 0.45 and 0.9 crop evapotranspiration, in a vineyard that has high evaporative demand, low residual soil moisture and restricted rooting volume. Under these conditions PRD did not affect yield but reduced irrigation amount decreased yield by 35% in both drip and PRD vines. While vines were more responsive to irrigation amount than to type of irrigation application, PRD did induce subtle physiological changes in the vines. Over the season gas-exchange in both levels of PRD irrigation was equal to the 0.9 Drip vine and significantly higher than the 0.45 Drip vines. PRD significantly changed the way in which vines used water in response to irrigation and also appeared to encourage root growth and soil moisture extraction at a deeper level. This effect was more pronounced at the higher irrigation level with the 0.45 ETc vines experiencing high levels of stress. These subtle physiological changes may have important long-term implications for vines. Application of reduced irrigation rates of PRD in high stress vineyards should be approached with caution.
![[Photo: Bethany Collins]](images/collins.gif)
Soil variability and its influence on the quality and composition of Shiraz grapes and wine
Soil forms an important part of the vineyard environment and is one of the few relatively static parameters. However there is still a large degree of soil variability in many vineyards which can contribute to considerable differences in the spatial patterns and magnitudes of variation in the composition of grapes within vineyard blocks. This project is an investigation of the influence that variation in physical and chemical soil parameters has on the physiology of the grapevine and the quality and composition of Shiraz grapes and wine.
Australian wine industry ‘winners and losers’ from climate change
Climate change will dramatically alter the growing season for Australian grapes and affect the wine styles produced here. Climate change projections developed by CSIRO for the years 2030 and 2050 were utilized to explore potential impacts to the Australian wine industry. A range of greenhouse gas emission scenarios and climate models were employed to determine the sensitivity of future grape growing possibilities to different projected warming levels. As expected, higher emissions resulted in greater impacts.
Temperatures in most Australian wine regions are projected to increase by between 0.3 to 1.7 degrees Celsius by 2030 and this will cause a shift in budburst dates, shorter growing seasons and earlier harvest dates. Modelling the effect of this temperature increase revealed that grape quality could be reduced in some regions by 12 per cent, with a low greenhouse gas emission future, ranging to 57 per cent, with a high emission future, by the year 2030 compared to current conditions – if no adaptive measures are implemented.
Because most projections of climate change indicate that warming will be taking place at a greater rate in inland Australia than in the coastal regions, the impact was calculated as it varies from region to region across the country. In present day cooler regions, the potential to grow longer season varieties exists in a future warmer climate, or sites, now too cool to grow and ripen grapes, could be successfully planted to produce premium wine. In other warmer inland regions, however, it was found that the temperature of the ripening period will become too warm to produce balanced wines from some or maybe all grape varieties growing there now.
![[Photo: Alison Oke]](images/oke.gif)
Precision Viticulture – The role of soil properties and microclimate in driving within-block variability in grape yield and quality
Precision Viticulture is the management of within-block variability in vine productivity. This project uses modern Precision Viticulture techniques to look at the factors driving within-vineyard variability in grape yield and quality. The spatial variation in yield and quality was identified in three case study vineyard blocks in the Yarra Valley, Mornington Peninsula and the Strathbogie Ranges over the period of 2003 to 2005. The project focus is to determine the primary factors driving the spatial variability in vine productivity. The major role that soil and climate play in defining vine productivity on a regional scale is well studied but little is known about their variability on a single vineyard scale. The extent and spatial structure of both the soil and climate characteristics have been identified in the three case study blocks The relationship between the spatial patterns of the vine productivity and environmental variables have then been investigated using geostatistical techniques such as Geographically Weighted Regression and k-means clustering
