Terroir 2008 banner
IVES 9 IVES Conference Series 9 Characterisation of viticultural and oenological practices in two French AOC in the middle Loire Valley: comparison of different methods to extract information from a survey among winegrowers

Characterisation of viticultural and oenological practices in two French AOC in the middle Loire Valley: comparison of different methods to extract information from a survey among winegrowers

Abstract

The type of wine is determined by environmental, plant materials and human factors. These factors are numerous and interact together, which makes it difficult to determine the hierarchy of their effects. We propose in this paper two methods to determine a hierarchy for these variables or their modalities. Using an inventory of agricultural, viticultural and oenological practices that are utilized for the production of Anjou Villages Brissac (AVB) or Anjou Rouges (AR) wines, it was attempted to determine for each of the variables whether their use differed significantly between the two appellations, and subsequently which of these practices were specific to each of the appellations.
Firstly, the variables and variable modalities were differentiated by a khi-squared distribution method. The database of the plots helped us to identify the practices which were used. An extraction of these plots was performed and the practices were classified by expertise.
Secondly, Classification and Regression Trees (CART) were used. This statistical method is non-parametric and non-linear and can, therefore, accommodate both continuous and categorical predictor variables. Variables can also be ranked in terms of their potential effect or relative importance. Using CART, the relative importance of each environmental, agricultural, viticultural and oenological variable in predicting whether a wine belonged to the appellation AVB or AR was determined and a final decision tree was constructed.
The final classification of variables using these different methods was compared and the observed differences were analysed. It remains to validate the hierarchical classification of the variables by means of experimentation with different technical itineraries on reference vineyards.

Download the PDF

DOI:

Publication date: December 8, 2021

Issue: Terroir 2008

Type : Article

Authors

SCHOLTUS-THIOLLET M. (1), MORLAT R. (1) & CAREY V.A. (2)

(1) INRA UEVV, UMT Vinitera, 42, rue Georges Morel BP 60057 49071 Beaucouzé France
(2) Lecturer, Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, 7602 Matieland, South Africa

Contact the author

Keywords

viticultural practices, oenological practices, global approach, CART, expertise

Tags

IVES Conference Series | Terroir 2008

Citation

Related articles…

Quality of Merlot wines produced from terraced vineyards and vineyards on alluvial plains in Vipava valley, Slovenia (pdo)

AIM: Different factors affect the style and quality of wine and one of the most important are environmental factors of vineyard location.

Read More

Seed phenolics oxidation: development of a new ripening index 

During ripening seed tannins evolve, as demonstrated by the taste and color changes. In this work we tried to develop an objective, easy and fast index, useful for winemakers. In this direction we propose two different spectrophotometric indexes, one related to the molecular structure and tannin subunits linkages, and the other related to the antioxidant properties. Especially the second one gave very interesting and unexpected results.

Read More

Climate change and viticulture in Nordic Countries and the Helsinki area

The first vineyards in Northern Europe were in Denmark in the 15th century, in the southern parts of Sweden and Finland in the 18th century at 55–60 degrees latitude. The grapes grown there have not been made into wine, but the grapes have been eaten at festive tables. The resurgence of viticulture has started with global warming, and currently the total area of viticulture in the Nordic countries, including Norway, is estimated to be 400–500 hectares, most of which is in Denmark. Southern Finland, like all southern parts of Northern Europe, belongs to the cool-cold winegrowing area.

Read More

The Fontevraud charter in favour of the viticultural landscapes

The viticultural regions of the world have the advantage of a remarkable diversity of landscapes which are the reflection of the winegrowers’ capacity to adapt to the different geomorphological and climatic specificities of the terroirs, more generally speaking, this aesthetic and heritage aspect of the terroir is also part and parcel of the notion of sustainable viticulture.

Read More

Influence of wood chips addition during alcoholic fermentation on wine phenolic composition

This study investigates the effect of wood chips addition during the alcoholic fermentation on the phenolic
composition of the produced wines. A series of wood chips, originating from American, French, Slavonia
oak and Acacia were added at the beginning of wine alcoholic fermentation. Besides, a mixture consisting
of 50% French and 50% Americal oak chips were added during the experimentation. The wine samples
were analyzed one month after the end of malolactic fermentation, examining various chemical
parameters such as total anthocyanins, total phenolic content, tannins combined with protein (BSA) and
ellagitannin content.

Read More