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…

Advancement of grape maturity – comparison between contrasting varieties and regions

Grapevine phenology has advanced across many regions, nationally and internationally, in recent decades under the influence of increasing temperatures, resulting in earlier
vintages (Jones and Davis, 2000, Petrie and Sadras, 2008, Tomasi et al., 2011, Webb et al., 2011. Earlier vintages have several ramifications for the wine industry. There are direct implications on quality, due to the fruit ripening during the hotter conditions of summer and early autumn, which then impacts grape composition and wine style (Sadras et al., 2013, Buttrose et al., 1971, Mira de Ordũna, 2010). There are also indirect implications where the fruit is perceived to ripen at a faster rate and the crop reach optimum maturity over a shorter period (Coulter et al., 2016).

Dialing in grapevine water stress indicators to better reflect holistic stress responses

Current remote sensing strategies rely heavily on reflectance data and energy balance modelling using thermal imagery to estimate crop water use and stress. These approaches show great promise for driving precision management decisions, but still require work to better understand how detected changes relate to meaningful physiological changes. Under water stress, grapevines exhibit a range of responses involving both biological and physical changes within leaves and canopies.

Produce wines with no quantifiable phytosanitary residues – Impact of washing grapes?

Consumer expectations are increasingly shifting towards “residue-free wines.” However, from an analytical standpoint, “zero” does not exist. Laboratories often use the quantification limits of analysis methods to signify ‘zero.’ Improved techniques now allow for the quantification of levels that were previously undetectable. This is why we prefer to use the term “unquantifiable residue” rather than “absence of residues.”

Unveiling Metschnikowia spp.: mechanisms and impacts of bioprotection in winemaking

Bioprotection, leveraging beneficial microorganisms, has emerged as a sustainable approach to modern winemaking, minimizing reliance on chemical preservatives like as sulfur dioxide (SO₂).

Olfactometry approach to assess odorant compounds of grape spirits used for Port wine production-first results

The production of Port Wine requires the addition of grape spirit to stop the fermentation, ensuring the desired sweetness