terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 The influence of pre-heatwave leaf removal on leaf physiology and berry development

The influence of pre-heatwave leaf removal on leaf physiology and berry development

Abstract

Due to climate change, the occurrence of heatwaves and drought events is increasing, with significant impact on viticulture. Common ways to adapt viticulture to a changing climate include site selection, genotype selection, irrigation management and canopy management. The latter mentioned being for instance source-sink manipulations, such as leaf removal, with the aim to delay ripening.

However, there is limited knowledge on how leaf removal influences water relations, especially when applied immediately before a heatwave. The purpose of this study is to investigate how leaf removal (reducing the total leaf area by 30 % in the apical part of the canopy) influences leaf physiology and berry quality under multiple abiotic stress conditions. Using climate chambers that allow a fine control of the climatic conditions, a 5-day heatwave with maximum temperature of 40 °C will be simulated. The factorial experiment includes two levels of soil water availability (irrigated, drought stressed) and two levels of defoliation (defoliated, not defoliated) with the intention to determine how pre-heatwave leaf removal influences (I) the usage of water under heat and drought conditions, (II) leaf physiological performance (gas exchange, photosystem efficiency), as well as (III) berry development and quality (yield, chemical composition and berry mechanical properties). Our hypothesis is that, by significantly reducing the leaf area (i.e. water transpiring surface) before a heatwave, fewer irrigation water is needed to maintain a favorable water status. The experiment is currently ongoing (summer 2023), therefore we cannot provide preliminary results at this stage. Nevertheless, with our results we hope to validate leaf removal a new and easy to implement short-term adaption strategy to make viticulture more resilient in the context of climate change.

DOI:

Publication date: October 9, 2023

Issue: ICGWS 2023

Type: Poster

Authors

Mario Wegher1, 2*, Georg Niedrist2, Massimo Tagliavini1, Carlo Andreotti1

1Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen-Bolzano, Bolzano, Italy
2Institute for Alpine Environment, European Academy of Bolzano/Bozen, Drususallee 1, Bolzano, 39100, Italy

Contact the author*

Keywords

grapevine, drought stress, heat stress, leaf removal, berry quality

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

New tool to evaluate color modifications during oxygen consumption in white and red wines

Measuring the effect of oxygen consumption on the color of wines as the level of dissolved oxygen decreases over time is very useful to know how much oxygen a wine can consume without significantly altering its color. The changes produced in wine after being exposed to high oxygen concentrations have been studied by different authors, but in all cases the wine has been analyzed once the oxygen consumption process has been completed. This work presents the results obtained with the use of an equipment designed and made to measure simultaneously the level of dissolved oxygen and the spectrum of the wine, during the oxygen consumption process from saturation levels with air to very low levels, which indicate the total consumption of the dosed oxygen[1,2].

Effect of foliar application of urea and nano-urea on the cell wall of Monastrell grape skins

The foliar application of urea has been shown to be able to satisfy the specific nutritional needs of the vine as well as to increase the nitrogen composition of the must. On the other hand, the use of nanotechnology could be of great interest in viticulture as it would help to slow down the release of urea and protect it against possible degradation. Several studies indicate that cell wall synthesis and remodeling are affected by nitrogen availability.

Late winter pruning induces a maturity delay under temperature-increased conditions in cv. Merlot from Chile

Chile is considered vulnerable to climate change; and these phenomena affect several mechanisms in the grape physiology and quality. The global temperature increase affects sugar contents, organic acids, and phenolic compounds in grapes, producing an imbalance maturity. In this sense, an alternative to reduce the impact is to perform pruning after vine budburst, known as “Late Pruning” (LP).

The evolution of the aromatic composition of carbonic maceration wines

The vinification by Carbonic maceration (CM) involves the process whereby the whole bunches are subjected to anaerobic conditions during several days. In this anaerobic condition, the grape endogenous enzymes begin an intracellular fermentation. This situation favors that whole grapes split open and release their juice into the tank, increasing the liquid phase that is fermented by yeasts [1]. Then, two types of wines are obtained; one from the free-run liquid in the tank (FCM) and other from the liquid after pressing the whole grape bunches (PCM). PCM wines are recognized as high quality young wines because their fruity and floral aromas[2] that although they are very intense at the end of the winemaking they gradually disappear during conservation.

Evaluation of Furmint clones in the Tokaj Wine Region

The ’Furmint’ is the most important grape variety in the Tokaj Wine Region, constituting around 65% of its vineyard area. Before the phylloxera disease many types were grown, but as selection started in the 20th century, its diversity dramatically narrowed. As a result, the cultivation of Furmint was based mainly on two heavy-cropping clones, T.85 and T.92 at the end of the ’80s. Aims of present clone research take into account that after solely quantity as target, quality emerged in the 1990’s and most recently, typicity appeared as more private estates began their own selection program.