WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 1 - WAC - Oral presentations 9 Spectral features of vine leaves are influenced by their mineral content

Spectral features of vine leaves are influenced by their mineral content

Abstract

The reflectance spectra of vegetation carry potentially useful information that can be used to determine chemical composition and discriminate between vegetation classes. If compared with analytical methods such as conventional chemical analysis, reflectance measurement provides non-destructive, economic, near real-time data.  Presently, results from reflectance measurements performed by spectroradiometry on leaves and branches of Vitis vinifera L. cv. Merlot and Cabernet Sauvignon from two vineyards in south Brazil are reported. The vineyards had different geological histories but were subjected to the same management. The objectives were to detect spectral differences between the vineyards, and to correlate these differences to variations in foliar traits like the chemical composition of vine leaves. To that end, seven vine parcels were selected for reflectance measurements and chemical analyses (of eleven elements) of vine leaves, and correlations between reflectance and chemical composition were looked for. An initial investigation by discriminant analysis applied to reflectance data of leaves and branches and to grape varieties as well allowed for good separation between vineyards and varieties (> 90% accuracy). By further investigating the correlations between leaf chemical composition and reflectance along the wavelength domain covered by the measurements, we found several well-determined wavelengths with Pearson correlation coefficients r > 0.7. Abundances of elements could be modelled up to 94% accuracy. These preliminary results, which have to be validated, suggest that variations in soil properties induce chemical differences in vine leaves that can be detected by reflectance measurements. Applications of this observation include the assessment of the chemical content of vine leaves by spectroradiometry as a fast, low-cost alternative to chemical analytical methods.

DOI:

Publication date: June 13, 2022

Issue: WAC 2022

Type: Article

Authors

Jorge Ducati, Adriane Thum

Presenting author

Jorge Ducati – Remote Sensing Center, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil

Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil 

Contact the author

Keywords

vineyard geology – chemical abundances – spectroradiometry – multivariate analysis

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

La région viticole Cotnari (Roumanie) et ses vins dans l’ensemble des grandes régions viticoles européennes

The author presents the geographical position of Romania as a vine-growing European country and analyses its relief and climate as factors of paramount importance for vine-growing environments. The climatogram system and the oenoclimatic aptitude index are applied in an analysis of the climatic characteristics of the Romanian vine-growing reg ions.

Multivariate strategies for red wines classification using stilbenes and flavonols content

Bioactive polyphenols from grapes and wines, like stilbenes and flavonols (SaF), are often determined to nutritional evaluation, but also for many other purposes. The objective of this study was to quantify SaF in red wines from “Campanha Gaúcha”, a large and young viticultural region from South Brazil. Moreover, through statistical analysis, evaluate the influence of these compounds according to varieties, production process, harvest years and micro-regions of cultivation. A total of 58 samples of red wines were analyzed by high-performance liquid chromatography coupled to diode array detector (HPLC-DAD) for determination of trans-resveratrol (R), quercetin (Q), myricetin (M), kaempferol (K), trans-e-viniferin (V) and their precursor, cinnamic acid (C).

Multidisciplinary strategies for understanding ill-defined concepts

Aims: The objective of the present work is to review strategies applied to decrypt multidimensional and ill-defined concepts employed by winemakers and to illustrate these strategies with recent applications.

Shading nets for the adaptation to climate change: effect on vine physiology and grape quality 

Viticulture is threatened by the environmental modification caused by climate change. Higher temperatures determine an acceleration of the ripening process, which can be detrimental to wine quality. In the mediterranean area, heat waves are also increasingly frequent, with consequent blocking of the vegetative activity of the vines and increased susceptibility to sunburn damage. thus, adaptation strategies are necessary to reduce stress and improve the quality of grape production. Amongst the various techniques available, shading nets represent an interesting alternative for their effects on canopy microclimate (i.e., reduction of photosynthetic activity, improvement of water use efficiency, and slowing down in the ripening process).

Perceptive interactions and wine typical fruity aroma 

In this study we developed a methodology to prepare aromatic reconstitutions from fractions of a wine organic extract and we assessed these reconstitutions both in wine model solution and in de- aromatized wine.