GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Assessing macro-elements contents in vine leaves and grape berries of Vitis vinifera using near-infrared spectroscopy coupled with chemometrics

Assessing macro-elements contents in vine leaves and grape berries of Vitis vinifera using near-infrared spectroscopy coupled with chemometrics

Abstract

Context and purpose of the study – The cultivated vine (Vitis vinifera) is the main species cultivated in the world to make wine. In 2017, the world wine market represents 29 billion euros in exports, and France contributes 8.2 billion (28%) to this trade, making it a traditional market of strategic importance. Viticulture is therefore a key sector of the French agricultural economy. It is in this context that the nutritional diagnosis of the vine is of real strategic interest to winegrowers. Indeed, the fertilization of the vine is a tool for the winegrower that allows him to influence and regulate the quality of the wine. Nowadays, nutrition analysis is made with CHNS analyzer for elemental particles, and mass-spectroscopy for macro and microelements. Such methods are destructive and time consuming, then results could be obsolete for the vine grower. Near-infrared spectroscopy coupled with chemometrics tools allows to developed models of prediction that can provide accurate information about nutrition status of the vine in the field. In this study, we concentrate on the relative amount of Carbon [C], Hydrogen [H], Nitrogen [N], Sulphur [S] in dry matter (DM) and the C:N ratio.

Material and methods – 252 samples of different organs (leaves blade, leaves petioles, pea sized berries and berries at véraison) of 4 varieties (Muscat, Chasselas, Négrette and Sauvignon blanc) were analyzed. Spectrum were taken on both fresh material and dried ones with a reflectance spectrometer. The spectra were pre-processed using multiple scatter correction (MSC) and 1st and 2nd order Savitsky-Golay derivative (D1 and D2), before developing the cross-validation models using partial least square (PLS) regression and test it on a prediction set.

Results – The coefficient of determination in prediction (r²), the roots mean square error of prediction (RMSEP) and the ratio of performance of prediction (RPD) were obtained for C (0.49, 14.6% of DM and 1.33 on fresh material with MSC, 0.45, 15.4% of DM and 1.26 on dry material with MSC), H (0.56, 1.71% of DM and 1.45 on fresh material with D1, 0.49, 1.88% of DM and 1.32 on dry material with D1), N (0.91, 1.12% of DM, 3.32 on fresh material with raw spectra, 0.95, 0.84% of DM and 4.39 on dry material with MSC), S (0.47, 0.319% of DM and 1.31 on fresh material with MSC, 0.46, 0.322% of DM and 1.30 on dry material with D2) and C:N ratio (0.85, 8.20 and 2.58 on fresh material with raw spectra, 0.87, 7.55 and 2.80 on dry material with D2). Results show that the near-infrared reflectance spectroscopy can be used to assessing the level of nitrogen nutrition in vine and the C:N ratio. All model performance could be improved by increasing the number of samples.

DOI:

Publication date: March 11, 2024

Issue: GiESCO 2019

Type: Poster

Authors

Sebastien CUQ1*, Valerie LEMETTER2, Olivier GEFFROY1, Didier KLEIBER1, Cecile LEVASSEUR-GARCIA3

1 Physiologie, Pathologie et Génétique Végétales (PPGV), Université de Toulouse, INP-PURPAN, Toulouse, France
2 Plateforme TOAsT, Université de Toulouse, INP-PURPAN, Toulouse, France
3 Laboratoire de Chimie Agro-industrielle (LCA), Université de Toulouse, INRA, INPT, INP-PURPAN, Toulouse, France

Contact the author

Keywords

Infrared, Spectroscopy, Elemental analysis, Vitis vinifera

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Impact of climate variability and change on grape yield in Italy

Viticulture is entangled with weather and climate. Therefore, areas currently suitable for grape production can be challenged by climate change. Winegrowers in Italy already experiences the effect of climate change, especially in the form of warmer growing season, more frequent drought periods, and increased frequency of weather extremes.
The aim of this study is to investigate the impact of climate variability and change on grape yield in Italy to provide winegrowers the information needed to make their business more sustainable and resilient to climate change. We computed a specific range of bioclimatic indices, selected by the International Organisation of Vine and Wine (OIV), and correlated them to grape yield data. We have worked in collaboration with some wine consortiums in northern and central Italy, which provided grape yield data for our analysis.
Using climate variables from the E-OBS dataset we investigate how the bioclimatic indices changed in the past, and the impact of this change on grape productivity in the study areas. The climate impact on productivity is also investigated by using high-resolution convection-permitting models (CPMs – 2.2 horizontal resolution), with the purpose of estimating productivity in future emission scenarios. The CPMs are likely the best available option for this kind of impact studies since they allow a better representation of small-scale processes and features, explicitly resolve deep convection, and show an improved representation of extremes. In our study, we also compare CPMs with regional climate models (RCMs – 12 km horizontal resolution) to assess the added value of high-resolution models for impact studies. Further development of our study will lead to assessing the future suitability for vine cultivation and could lead to the construction of a statistical model for future projection of grape yield.

Effect of fertigation strategies to adapt PGI Côtes de Gascogne production to hot vintage

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.

Towards a regional mapping of vine water status based on crowdsourcing observations

Monitoring vine water status is a major challenge for vineyard management because it influences both yield and harvest quality. It is also a challenge at the territorial scale for identifying periods of high water restriction or zones regularly impacted by water stress. This information is of major importance for defining collective strategies, anticipating harvest logistic or applying for irrigation authorisation. At this spatial scale, existing tools and methods for monitoring vine water status are few and often require strong assumptions (e.g. water balance model). This paper proposes to consider a collaborative collection of observations by winegrowers and wine industry stakeholders (crowdsourcing) as an interesting alternative. Indeed, it allows the collection of a large number of field observations while pooling the collection effort. However, the feasibility of such a project and its interest in monitoring vine water status at regional scale has never been tested.

The objective of this article is to explore the possibility of making a regional map of vine water status based on crowdsourcing observations. It is based on the study of the free mobile application ApeX-Vigne, which allows the collection of observations about vine shoot growth. This information is easy to collect and can be considered, under certain conditions, as a proxy for vine water status. This article presents the first results obtained from the nearly 18,000 observations collected by winegrowers and wine industry stakeholders during 2019, 2020 and 2021 seasons. It presents the vine shoot growth maps obtained at regional scale and their evolution over the three vintages studied. It also proposes an analysis of the factors that favoured the number of observations collected and those that favoured their quality. These results open up new perspectives for monitoring vine water status at a regional scale but above they provide references for other crowdsourcing projects in viticulture.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.