 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 The use of elicitors in the vineyard to mitigate the effects of climate change on wine quality

The use of elicitors in the vineyard to mitigate the effects of climate change on wine quality

Abstract

The wine sector is being directly affected by climate change. Temperatures above 30ºC can cause a lag between the ripening of the berry pulp (a rapid increase in sugar content) and the skin, due to the longer period required for the skin maturity (1,2). This leads to unbalanced wines, with high alcohol content and lacking in phenolic maturity (3). Many studies have been carried out searching for mechanisms to increase the content of polyphenols and to synchronize the two types of maturity. One option could be the use of elicitors, whose mechanism of action triggers biosynthetic pathways for defense compounds, including phenolic compounds (4). The objective of this study was to determine if the application of three different elicitors to Monastrell grapes during the maturation period could accelerate the synthesis of phenolic compounds and allow the obtention of wines with high phenolic concentration and moderate alcohol content. The elicitors used have been: LalVigneTM Mature, a compound made up of 100% specific fractions of Saccharomyces cerevisiae derivatives; Harpin αβ, a protein of bacterial origin; BION® 50 WG, a chemical inducer composed of the active material acibenzolar-S-methyl. This study has been carried out in 2019, in two different vineyards, one conducted with a trellis system and drip watered and the other one in a non-irrigated globet system. The treatment consisted in two applications at two different moments, at veraison and 14 days later. The grapes were harvested with 22ºBrix and also a control batch was harveted at 26ºBrix. Once the wines were bottled, the physicochemical and chromatic parameters by spectrophotometry were analyzed. The control wine from the trellised vineyard had an alcohol content of 13.81%, and the wines made with grapes treated with elicitors a presented 12.5%, 12.40% and 12.90% when Lavigne, Harpin and Bion were applied, respectly. The alcohol content of the wines made from the grapes from the non-irrigated vineyard was 14.37% for the control wine and 12.46, 13.18 and 12.85% for those made from grapes treated with Lavigne, Harpin and Bion, respectively. In both vineyards, the wines made from the grapes treated with the different elicitors have a lower pH and higher acidity than their respective control wine, mainly in the non-irrigated vineyard. Regarding the wine chromatic parameters and for the wines from elicitor-treated grapes from both vineyards, they presented higher tannin content and similar values of total phenols and color intensity than their control wines, not forgetting that the alcohol content of the former wines was one to two alcohol degrees lower than control wines. Therefore, the use of elicitors can be a promising treatment to speed up the accumulation of phenolics in the grapes so they can be harvested with a lower sugar content and obtain wines with less alcohol content and with an unaffected chromatic parameters.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

María-Pilar Martínez-Pérez

Department of Food Science and Technology, Faculty of Veterinary Sciences, University of Murcia, 30100 Murcia, Spain,Ana-Belén Bautista-Ortín, Department of Food Science and Technology, Faculty of Veterinary Sciences, University of Murcia, 30100 Murcia, Spain. Encarna Gómez-Plaza, Department of Food Science and Technology, Faculty of Veterinary Sciences, University of Murcia, 30100 Murcia, Spain.

Contact the author

Keywords

wine, grape, elicitors, phenolic compounds

Citation

Phenolic composition of Tempranillo Blanco grapes changes after foliar application of urea

Our research aimed to determine the effect and efficiency of foliar application of urea on the phenolic composition of Tempranillo Blanco grapes. The field experiment was carried out in 2019 and 2020 seasons and the plot was located in D.O.Ca Rioja (North of Spain). The vineyard was Vitis vinifera L. Tempranillo Blanco and grafted on Richter-110 rootstock. The treatments were control (C), whose plants were sprayed with water and three doses of urea: plants were sprayed with urea 3 kg N/ha (U3), 6 kg N/ha (U6) and 9 kg N/ha (U9). The applications were performed in two phenological stages, pre-veraison (Pre) and veraison (Ver). Also, each of the treatments was repeated one week later. Control and treatments were performed in triplicate and arranged in a randomised block design. Grapes were harvested at optimum ripening stage. High-performance liquid chromatography was used to analyse the phenolic composition of the grapes. Finally, the results obtained from the analytical determinations – flavonols, flavanols and non-flavonoid (hydroxybenzoic acids, hydroxycinnamic acids and stilbenes) – were studied statistically by analysis of variance. The results showed that, in 2019, U6-Pre and U9-Pre treatments increased the hydroxybenzoic acid content in grapes, and also all foliar treatments applied at Pre enhanced the stilbene concentration. Moreover, U3-Ver was the only treatment that rose flavonol and stilbene contents in the Tempranillo Blanco grapes. In 2020, all treatments applied at Pre enhanced the flavonol concentration in grapes. Furthermore, U3-Pre and U9-Pre treatments increased stilbene content in grapes. Nevertheless, the hydroxybenzoic acid content was improved by U6-Ver and U9-Ver and besides, hydroxycinnamic acid concentration in grapes was increased by all treatments applied at Ver. In conclusion, the lower and highest dose of urea (U3 and U9), applied at pre-veraison, were the best treatments to improve the Tempranillo Blanco grape phenolic composition.

Grapevine varietal diversity as mitigation tool for climate change: Agronomic and oenologic potential of 14 foreign varieties grown in Languedoc region (France)

Climate change effects in Languedoc include an expected rise in temperatures, increased evapotranspiration as well as more severe and frequent climatic hazards, such as frost, drought periods and heat waves. For winegrowers theses phenomena impact both yield and quality, resulting in more frequent unbalanced wines. Research on identified mitigation tools for vineyard management is necessary to improve resilience of grapevine agrosystems. Varietal assortment is one of them. This study focuses on agronomic and oenologic potential of 14 foreign varieties grown in Languedoc French region. Fourteen grapevine varieties were monitored during 2021 from June until harvest on eight different sites, some of which occurring on more than one site adding up to 21 different modalities: 7 white varieties Alvarinho B, Assyrtiko B (2), Malvasia Istriana B, Parellada B, Verdejo B, Verdelho B, Xarello B, and 7 black varieties Saperavi N (2), Touriga nacional N, Baga N, Aleatico N, Montepulciano N (2), Primitivo N (3), Calabrese N (3). Varietals were compared through the following parameters: phenology was assessed by using the information collected in the Database Network of French Vine Conservatories (INRAE-SupAgro-IFV, 2005-2015). The number of inflorescences for shoots from secondary buds and bourillons and suckers were observed to assess post-bud break frost tolerance potential. Grapevine water status was studied through stem water potential measurement, observation of foliage symptoms of drought, and 𝛿13C on must. Frequencies and intensities of downy mildew, powdery mildew, and black rot attacks were estimated before harvest on leaves and clusters and botrytis at harvest to assess disease susceptibilities. Berry composition was monitored from end of veraison until harvest. Yield and mean bunch weight were also calculated. Varieties were then ranked on a 1-4 scale for each parameter and compared through PCA. Forty two stations of the Mediterranean basin were compared by PCA with the Multicriteria Climatic Classification indicators in order to confront the collected information during 2021 campaign to the hypothesis that plants coming from dry and hot regions are genetically adapted to such climatic conditions.

Phenological characterization of a wide range of Vitis Vinifera varieties

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.

Different soil types and relief influence the quality of Merlot grapes in a relatively small area in the Vipava Valley (Slovenia) in relation to the vine water status

Besides location and microclimatic conditions, soil plays an important role in the quality of grapes and wine. Soil properties influence…

Short-term relationships between climate and grapevine trunk diseases in southern French vineyards

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...