GST (growing season temperature) best measure for viticulturists
on 02/02/12 at 5:39 pmWine
Pioneering cool climate viticulturist Dr Andrew Pirie, of Tamar Ridge, revitalised GST as a single measure offering a refined definition of cool climate at the opening session of the 8th International Cool Climate Symposium in Tasmania.
Pirie tested some of the current climate indices by trialling how successful they are in Tasmania, no easy task in a complex viticultural environment.
Such parameters as air temperature, soil temperature, rainfall, humidity, wind, solar radiation, UV, soil moisture and evapo-transpiration “changed more than I expected, and will all have a bearing on the climate of a vine.”
While “no one index will tell you everything” Pirie said, he arrived at GST, which has been around for some time, because “it seems to work everywhere” across the winemaking world, whereas, he added, indices such as HDD (heat degree days) and MJTs (mean January/July temperatures) do not.