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…

Investigating the Ancient Egyptian wines: The wine jars database

In Ancient Egypt, wine was a luxury product consumed mainly by the upper classes and the royal family and offered to gods in daily religious rituals in the temples.
Since the Predynastic (4000-3100 BC) period, wine jars were placed in tombs as funerary offerings. From the Old Kingdom (2680-2160 BC) to the Greco-Roman (332 BC-395 AD) period, viticulture and winemaking scenes were depicted on the private tombs’ walls. During the New Kingdom (1539-1075 BC), wine jars were inscribed to indicate: vintage year, product, quality, provenance, property and winemaker’s name and title.

Impact of temperature and solar radiation on grape composition variability in the Saint-Emilion winegrowing area 

Grape composition is strongly influenced by climate conditions. Their expected modifications in near future, notably because of increased temperatures, could significantly modify the biochemical composition of berries at harvest, and thus wine typicity and quality. Elevated temperatures favor sugar accumulation in grapes, enhance malic acid degradation and modify the amino acid content. They also reduce significantly anthocyanin accumulation in Merlot, leading to the imbalance between anthocyanins and sugars, while no significant effects on final anthocyanin levels were reported in Tempranillo[1] and finally affect aromas or aroma precursors.

Physicochemical behaviour of wine spirit and wine distillate aged in Sherry Casks® and Brandy casks

Brandy is a spirit drink made from “wine spirit” (<86% Alcohol by Volume – ABV; high levels of congeners and they are mainly less volatile than ethanol), it may be blended with a “wine distillate” (<94.8%ABV; low levels of congeners and these are mainly more volatile than ethanol), as long as that distillate does not exceed a maximum of 50% of the alcoholic content of the finished product[1]. Brandy must be aged for at least 6 months in oak casks with <1000L of capacity. During ageing, changes occur in colour, flavour, and aroma that improve the quality of the original distillate.

Effect of spray with autochthonous Trichoderma strains and its secondary metabolites on the quality of Tempranillo grape

Trichoderma is one of the most widely used fungal biocontrol agents on vineyards due to its multiple benefits on this crop, such as its fungicidal and growth promoting capacity. In this work, we have analyzed the effect on the concentration of nutrients in grapevine leaves and on the quality of the grape must after spraying an autochthonous strain of Trichoderma harzianum and one of the main secondary metabolites produced by this genus, 6-pentyl-α-pyrone (6PP).

Characterization of non-cultivated wild grapevines in Extremadura (Spain) 

Several Eurasian wild grapevine populations were found along Extremadura region (southwestern Spain). For conservation and study, one individual from four different populations (named L1, L2, L5 and L6) was vegetatively propagated and planted at Instituto de Investigaciones Agrarias Finca La Orden (CICYTEX), Badajoz. The aim of the present work was to characterize those conserved individuals from four different populations based on both an ampelographic description and a molecular analysis. Three vines per individual were studied.