Modelling the effects of daily extreme weather on grapevine and wine quality

Abstract

Modelling the effects of climate change on vegetation and agriculture is arguably one of the most challenging issues the scientific community has to deal with in recent times. Grapevine being among the world’s old and most expensive cultivated crops with winemaking consisting of a rich history of centuries-old traditions makes contemporary research into modelling climate effects on viticulture of significant interest. Novel approaches are explored for gaining more scientific knowledge on the phenomenon climate change, in particular its potential impact on grapevine growth stages, phenological events and wine quality. In this context, the paper looks at literature on recent χ2 analysis based approach to establishing associations between daily extreme weather conditions and some perennial crop yield at larger spatiotemporal scales, i.e., yield comparisons among wine regions/ national annual yield of apples, walnuts, oranges, almonds and avocados with three decade old data. Consequently, recent novel approaches investigated at the Geoinformatics Research Centre (GRC) to studying the effects of daily maximum temperature on grapevine yield using data at a different spatiotemporal scale along with results obtained are outlined. The paper then details on extending the approaches to other daily extreme weather data; minimum air and soil (grass) temperatures with a) a single vineyard’s yield over a period of 12 years (1997-2009) and b) weather conditions, recorded at a nearby weather monitoring station belonging to the National Institute of Water and Atmosphere (NIWA), extracted via NIWA’s web portal. The results show interesting nexuses between daily extreme weather conditions, the independent variables and grapevine yield, the dependent variable at spatiotemporal scales not previously ascertained i.e., at a vineyard (micro scale) but using macro climate data. The approach provides a means to gaining precise information relating to climate effects on viticulture, useful for training grapevines appropriately and thereby improving the quality of grapevine yield/ vintage.