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…

Techniques for sunburn reduction in bunches in Vitis vinifera L. cv. Graciano

Sunburn results from a combination of excessive photosynthetically active radiation (PAR) and UV radiation and temperature that can be exacerbated by other stress factors such as water deficit. Sunburn is a physiological disorder that affects the visual and organoleptic properties of grapes. The appearance of brown and necrotic spots severely affects the commercial value of the fruit, and in extreme cases, significantly decreases yield. This damage occurs with some frequency in sensitive varieties such as Graciano.

Aroma profile of Tempranillo tropical red wines from different seasons in the São Francisco valley, northeast of Brazil

Aromatic characteristics of wines are strongly influenced by agronomical and enological factors, depending of the climate, cultivar and winemaking process. Tropical wines are a new concept of vitiviniculture that is being developped in the Northeast of Brazil since the 80’s, located between 8-9º latitude of the South Hemisphere, where the second most important cultivar used for reds is Tempranillo. In this condition, vines produce grapes and enologists elaborate wines twice a year, because high temperatures, solar radiation and water availability for irrigation.

Differentiating and grouping of oltrepo’ pavese environments according to grape maturation

The maturation patterns process has been very studied. In particular the modelization of the sugars and titratable acidity during the ripening period was an important approach, in particular for the prediction of harvest date (Barillere et al., 1988; Jourion et al.,1987; Maujean et al., 1983; Scienza, 1989). In Oltrepò Pavese, the widest viticultural district of Lombardy – Northern Italy – (about 15000 hectares), grape maturation trends shows high variability, due to the large variation in environmental characteristics of vineyards (altitude, exposure, soil type, mesoclimate) and to “cultivar x environment” interaction.

From vineyard to bottle. Rationalizing grape compositional drivers of the expression of valpolicella aroma ‘terroir’

AIM: Valpolicella is a renowned Italian wine-producing region (Paronetto, 1981). Wines produced in its different sub-regions are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity

Regionality in Australian Shiraz: Sensory profiles of wines from six regions and their associations with chemical, geographical and climatic elements

Aim: Regional characters relating to Shiraz in Australia are not well documented. This study aimed to characterize the sensory, chemical and climate profiles of wines from various Australian Shiraz producing regions.