Terroir 2016 banner
IVES 9 IVES Conference Series 9 Terroir effects from the reflectance spectra of the canopy of vineyards in four viticultural regions

Terroir effects from the reflectance spectra of the canopy of vineyards in four viticultural regions

Abstract

Knowledge of the reflectance spectrum of grape leaves is important to the identification of grape varieties in images of viticultural regions where several cultivars co-exist. As a non-destructive technique, spectroradiometry delivers reflectance spectra with high signal-to-noise ratios.

This work reports results from field measurements of the reflectance spectra of five grape varieties in the spectral range 450nm to 2500nm, performed in south Brazil. Four viticultural regions were visited, with different soils originated from basalt, granite, and sandstone. In vivo measurements of Cabernet Sauvignon, Merlot, Pinot Noir, Chardonnay and Italian Riesling were performed. All spectra were normalized to have unit area and were compared. The very high signal/noise ratio allowed the systematic detection of subtle spectral features of each variety, with intensities of the order of 10-4 to 10-5 with respect to the normalized reflectance range from 0 to 1. These spectral features were attributed to differentiation factors as the presence of pigments in leaves, which has an impact in leaf texture and so in infrared reflectance. Spectral differentiation due to terroir effects was also investigated.

The spectral database was subjected to statistical discriminant analysis to search for separation either of grape varieties and terroirs/regions. Grape varieties and terroirs were separated to accuracies of up to 100%. This methodology can be applied to zoning studies which look for typicity parameters; besides, a detailed knowledge of the spectral signatures of grape varieties can be relevant to the development of identification algorithms used to classify remote sensing images of viticultural regions where several cultivars are present, and to in-field inspections using radiometers.

Download the PDF

DOI:

Publication date: June 23, 2020

Issue: Terroir 2016

Type: Article

Authors

Jorge Ricardo DUCATI (1), Magno G. BOMBASSARO (1), Diniz C. ARRUDA (1), Virindiana C. BORTOLOTTO (2), Rosemary HOFF (3)

(1) Remote Sensing Center, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, CEP 91501-970 Porto Alegre, Brazil
(2) Instituto de Ciências Agrárias e Ambientais, Universidade Federal de Mato Grosso, Av. Alexandre Ferronato 1200, CEP 78557-267 Sinop, Brazil
(3) Centro Nacional de Pesquisas em Uva e Vinho, Empresa Brasileira de Pesquisa Agropecuária, Rua Livramento 515, CEP 95700-000 Bento Goncalves, Brazil

Contact the author

Keywords

Remote Sensing, Spectroradiometry, Soils, Reflectance, Classification

Tags

IVES Conference Series | Terroir 2016

Citation

Related articles…

VITIGEOSS Business Service: Task scheduling optimization in vineyards

Agriculture plantations are complex systems whose performance critically depends on the execution of several types of tasks with precise timing and efficiency to respond to different external factors. This is particularly true for orchards like vineyards, which need to be strictly monitored and regulated, as they are sensitive to diverse types of pests, and climate conditions. In these environments, managing and optimally scheduling the available work force and resources is not trivial and is usually done by teams of senior managers based on their experience. In this regard, having a baseline schedule could help them in the decision process and improve their results, in terms of time and resources spent.

Read More

Quantification of newly identified C8 aroma compounds in musts and wines as an analytical tool for the early detection of Fresh Mushroom Off-Flavor

The Fresh Mushroom Off-Flavor (FMOff) is a concerning undesirable aroma in wine specific of certain vintages, characterized by a typical button mushroom aroma. The appearance of this off-flavor is linked to the presence of certain fungus on the grape [1-3].

Read More

Development of a new method for detecting acetic acid bacteria in wine

The presence of acetic acid bacteria in wine can lead to the appearance of acetic acid at concentrations above the perception threshold, causing the wine rejection by the consumer. During the winemaking process, avoiding the presence of acetic acid bacteria is very difficult, as there is always a residual population accompanying the wine[1], and the problem arises with the significant development of these microorganisms that metabolizes large amounts of acetic acid.
The concern of wineries to control the presence of acetic acid bacteria in wines during their conservation is due to the absence of simple and effective analyses that allow the detection of these microorganisms in the initial stages.

Read More

Intra-varietal diversity in cv. ‘Tempranillo Tinto’: phenological stages

‘Tempranillo Tinto’ is one of the most relevant grapevine cultivars worldwide. Despite its early ripening and relatively short vegetative cycle, which may not be ideal for high-quality grape and wine production in warming conditions, its long-standing cultivation has led to an intense multiplication by cuttings, which originated the high level of clonal variation currently available. Now, this intra-varietal diversity provides an interesting opportunity for cultivar improvement by identifying genotypes with better adaptation potential.

Read More

Classification of the wine-growing environment of Central Mancha (Spain). First works

This paper describes a zoning study performed on a vast territory of around 86,500 hectares, situated in the countryside area of La Mancha Central (Castilla-La Mancha). The aim of the study was to classify the environment according to a small number of ecological criteria, establish the relevant territorial units and generate thematic maps with the different levels of criteria employed and synthetic maps by crossing these criteria.

Read More