Benchmarking Victorian Shiraz vineyards

Abstract

Vineyard score sheets re-designed to place greater emphasis on vine balance at the time of veraison were used in a benchmarking study carried out in 25 Shiraz vineyards in North East Victoria, resulting in greater understanding of factors linked to good grape and wine quality.

Summary

This report concerns the 2004/2005 season for five regions within the North East zone (namely the Alpine Valleys, Beechworth, Glenrowan, King Valley and Rutherglen) and follows earlier benchmarking exercises. In addition to using the revised score sheets, grape growers undertook a range of measurements in the field and were trained in berry sensory analysis to enhance their ability to describe grape characteristics. Good scores were achieved where grapes were grown with moderate to high temperature summation units from veraison to harvest and where there had been attention to canopy management resulting in warmer temperatures in the morning and no excessive afternoon heat loads. Temperature changes, found to be useful as a guide to canopy management, were monitored using data loggers placed in the bunch zone. No single quality parameter was found to be fundamental, however, for every wine style as demonstrated by some grape samples with a high colour score not making the best wine.

Participating grape growers developed a deeper understanding of vine balance, gained experience with a new vineyard assessment system and were able to trace the effects of their vine management on grape and wine quality.