Topoclimate and wine quality: results of research on the Gewürztraminer grape variety in South Tyrol, northern Italy

Carlo Ferretti

doi:10.20870/oeno-one.2021.55.1.4531

Abstract

The aim of the study was to identify the ecological indicators that facilitate predictive analysis and to search for patterns in local geographical information to identify risks and opportunities in viticulture. The study focused on environmental factors that significantly affect the ripeness of the Gewürztraminer grape variety cultivated near Tramin, a village in northern Italy. In particular, the reliability of the new Solar Radiation Identity (SRI) topoclimate classification method was tested, along with its predictive capability in terms of the biosynthetic activity of the vine and the quality of its grapes. The SRI index characterises each vineyard in a precise and comparable way and helps to understand the way in which the topoclimate acts as an important abiotic stress factor for vines. A direct relationship between grape must sugar content and the SRI topoclimate index was observed. Our findings indicate an increase in sugar content of approximately 0.8 °KMW for every 10 points of the SRI index. Thus, a novel prediction model of grape ripening based on an SRI curve analysis is proposed. The correct application of the SRI index could be useful for discriminating and predicting geographical charactersitics of a given area strongly connected to ecological diversity and wine quality. It could support decision making in viticulture in terms of, for example, correctly matching vineyard and grape varieties, reducing wine vulnerability and production risk and predicting optimal ripeness and harvesting days. The use of the SRI prediction curve could help in adopting a more sustainable approach to agriculture and in finding new methods for adapting to climate change, such as by improving the match between the cultivars’ phenological status, vineyard location and growing season average temperature.

Highlights

The combination of many natural components such as geography, soil, climate and grape variety, together with local culture and winemakers, influences the quality of wines all over the world
The harvesting period is mainly driven by growing season air temperature (Parker et al, 2011) and the specific temperature requirements of the grapevine variety (Parker et al, 2013)
The long-term analyses for all three environmental monitoring stations installed at Tramin, indicate that their seasonal temperature trends correspond; daily averages increased between April and May and the peaks in temperature occurred between the end of June and mid-August

Summary

Introduction

The combination of many natural components such as geography, soil, climate and grape variety, together with local culture and winemakers, influences the quality of wines all over the world. A single ecological element does not necessarily determine the specificity of place for a particular grape variety; it is rather the combination of many geographical elements that creates distinctive conditions for vineyards and their wines (Jackson, 2014). These factors influence the biosynthetic activities of plants and their phenology, promoting biodiversity and the qualitative predispositions of grapes and wine. It is always necessary to observe and precisely classify all those environmental elements that can affect the vegetative, productive and qualitative expressions of a cultivar This is a difficult challenge for vineyards set in geographically complex territories, like the Alto Adige DOC (Controlled Designation of Origin) wine region, in the middle of the Alpine mountains in northern Italy

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Conclusion