terclim by ICS banner
IVES 9 IVES Conference Series 9 Impact of canopy management on thiol precursors in white grapes: a six-year field study

Impact of canopy management on thiol precursors in white grapes: a six-year field study

Abstract

The mechanisms behind thiol precursor accumulation in grapes remain incompletely understood, nor are the ways in which they can be improved by agronomic practices. A six-year field trial studied the physiological response of the Swiss white cultivar Vitis vinifera Arvine, rich in varietal thiols and precursors, to canopy management, i.e. leaf removal and canopy height.. Five treatments were set up in a randomized block design to assess the impacts of 1) pre-flowering LR (i.e. pre-flowering or full-flowering stages) and 2) compensating for the leaf area removed in the cluster zone by increasing the trimming height (i.e. 100 or 150 cm canopy height), compared with a non-defoliated control treatment.

Intensive pre-flowering LR severely reduced yield potential (–47% on average) and reduced the concentration of 3-mercaptohexanol precursors (P-3MH) in the must (–21%; p-value < 0.10). Decreasing earliness modulated the impact of LR on yield (–12%) and P-3MH concentration (–6%). Compensating for suppressed leaf area by increasing the trimming height slightly enhanced grape ripening (+1% total sugars; –3% titratable acidity), slightly improved the overall quality of the wine (color intensity, volume), while having no impact on must P-3MH concentration or on wine bouquet.

Observing the long-term impact of each LR treatment separately provided insights into the physiological mechanisms influencing fruit development and aroma formation. This trial is part of a larger project on canopy management and its impact on grape composition in temperate Swiss climatic conditions.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Article

Authors

Thibaut Verdenal1*, Vivian Zufferey1, Ágnes Dienes-Nagy2, Gilles Bourdin2, Jean-Laurent Spring1

1 Agroscope, avenue Rochettaz 21, 1009 Pully, Switzerland
2 Agroscope, route de Duillier 60, case postale 1012, 1260 Nyon 1, Switzerland

Contact the author*

Keywords

leaf removal, canopy height, 3-mercaptohexanol, grapevine, wine aroma

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

A global and regional study on winegrowers’ perceptions and adaptations to climate change

Aim: The aim of this study was to explore the current and future state of the wine sector in the context of climate change, where the goal was to obtain greater understanding on winegrowers’ perceptions and adaptations to a changing climate and its associated impacts. The study sought to provide both a global and regional perspective on these issues.

Timing of leaf removal effects on vitis vinifera L. Cv. Grenache differed on two contrasting seasons

Warming trends over the winegrowing regions lead to an advance of grapevine phenology, diminution of yield and increased sugar content and must pH with a lower polyphenol content, especially anthocyanins. Canopy management practices are applied to control the source sink balance and improve the cluster microclimate to enhance berry composition. We hyphothesized that an early leaf removal might promote a delayed ripening through severe defoliation after fruitset; whereas, a late leaf removal at mid-ripening would reduce sugar accumulation.

Foliar application of urea improved the nitrogen composition of Chenin grapes

The nitrogen composition of the grapes directly affects the developments of alcoholic fermentation and influences the final aromatic composition of the wines. The aim of this study was to determine the effect and efficiency of foliar applications of urea on the nitrogen composition of grapes. This study was carried out during 2023 vintage and in the Chenin vineyard located in Estacion Experimental Mendoza (Argentina). Three urea concentrations 3, 6 and 9 Kg N/ha (C1, C2, and C3, respectively) and control (T) were applied in this vineyard at veraison.

Zonificación climática de las D.O. Rueda y Toro y vinos de la tierra de medina del campo

La producción vitícola es el resultado de una serie de factores influyentes (variedad, patron) dentro de un medio ecológico­-climatico-edafico, en el que se interactua por medio de técnicas de cultivo adecuadas.

ALCOHOLIC FERMENTATION AND COLOR OF ROSÉ WINES: INVESTIGATIONS ON THE MECHANISMS RESPONSIBLE FOR SUCH DIVERSITY

Color is one of the key elements for the marketing of rosé wines due to their packaging in transparent bottles. Their broad color range is due to the presence of pigments belonging to phenolic compounds extracted from grapes or formed during the wine-making process. However, the mechanisms responsible for such diversity are poorly understood. The few investigations performed on rosé wines showed that their phenolic composition is highly variable, close to that of red wines for the darkest rosés but very different for light ones [1]. Moreover, large variations in the extent of color loss taking place during fermentation have been reported but the mechanisms involved and causes of such variability are unknown.