Early maturity of grapevines in SE Australia between 1995 and 2009 was associated with early onset rather than faster ripening Victor Sadras and Paul Petrie CCRSPI Conference, Melbourne 15-17 February 2011
Aim 1 measure the effects of elevated temperature on vines and wines temperature x variety temperature x fruit load temperature x water
Aim 2 modelling grapevine maturity for harvest and post-harvest operations
Aim 2 modelling grapevine maturity for harvest and post-harvest operations Current approach - direct measurements - fixed rate 1 o Bé per week
Sadras et al. (2008) Australian J Grape & Wine Research 14 , 250
Cab Sauvignon, 1993-2006 Rate of change in time to 12 Be Petrie & Sadras (2008) Australian J Grape & Wine Research 14: 33 Rate [d/yr]
1. Sadras VO, Petrie PR (2011). Quantifying the onset, rate and duration of sugar accumulation in berries from commercial vineyards in contrasting climates of Australia. Australian Journal of Grape and Wine Research in press. 2. Sadras VO, Petrie PR (2011). Climate shifts in south-eastern Australia: early maturity of Chardonnay, Shiraz, and Cabernet Sauvignon is associated with early onset rather than faster ripening. Australian Journal of Grape and Wine Research in press.
Growers, vineyard and weight bridge staff from Treasury Wine Estates Ltd. for collecting the maturity and yield data. Harry Driscoll for help with the database. Francisco Sadras and Mary Barnes for help with data analyses. Grape and Wine Research and Development Corporation of Australia and the Department of Agriculture, Forestry and Fisheries for financial support. Thanks
Conclusions Warming is a complex syndrome including biologically relevant factors such as higher vapour pressure deficit with direct consequences for grapevine ripening. Early ripening associated with the warming syndrome over recent decades has been primarily related to shifts in onset rather than increase in rate of ripening. A simple onset-rate model can be coupled with (i) short-term temperature forecasts to predict the trajectory of sugaring for management purposes, and (ii) long-term records of temperature to produce probabilistic profiles of maturity date.