Terroir 2020 banner
IVES 9 IVES Conference Series 9 Leaf removal to regulate fruit ripening in Cabernet-Sauvignon

Leaf removal to regulate fruit ripening in Cabernet-Sauvignon

Abstract

Aim: Under the effects of climate change it is becoming increasingly common to observe excessively fast sugar accumulation while anthocyanin and flavour development are lagging behind. Understanding the impact of different leaf removal techniques on ripening will provide vineyard managers with a canopy management strategy suitable for regulating sugar accumulation, phenolic maturity and flavour ripeness, thereby helping to mitigate these negative effects. The aim of this research was to quantify the impacts of three different leaf removal techniques on the canopy architecture and ripening of Cabernet Sauvignon.

Methods and Results: Treatments were performed at veraison (~14 °Brix) and included: i) Control, ii) Leaf plucking around the bunches iii) Leaf plucking the top two thirds of shoots apical to the bunches, and iv) Shoot trimming. On the date of harvest no significant difference in grape TSS was observed between treatments. Other results including the effect of the treatments on acidity, anthocyanins, phenolics, and tannins were somewhat inconclusive.

Conclusions:

While various other studies have shown the potential to achieve slower grape sugar accumulation without affecting the concentration of anthocyanins, phenolics, and tannins, the results of this study do not indicate a decrease in the rate of grape sugar accumulation as a result of the investigated defoliation techniques.

Significance and Impact of the Study: Given the cost of implementing these treatments the results of this study do not support the use of these methods for the purpose of delaying fruit ripening in a hot Australian climate.

Download the PDF

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

Patrick O’Brien1, Cassandra Collins1,2, Roberta De Bei1*

1The University of Adelaide, School of Agriculture, Food and Wine, Waite Research Institute, PMB 1 Glen Osmond, 5064, South Australia, Australia.
2ARC Industrial Transformation Training Centre for Innovative Wine Production, Waite Research Institute, PMB 1 Glen Osmond, 5064, South Australia, Australia

Contact the author

Keywords

Delayed ripening, leaf removal, shoot trimming, canopy management, Cabernet-Sauvignon

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Dimethyl sulfide transfer through wine closures during bottle aging: implications for wine aroma management

Dimethyl sulfide (DMS) is a volatile sulfur compound with a complex role in wine aroma, contributing both desirable and undesirable sensory characteristics depending on its concentration (1).

Read More

The antioxidant properties of wine lees extracts in model wine

While the ethanol and tartaric acid contained in wine lees are typically recovered by distilleries, the remaining solid fraction (yeast biomass) is usually disposed of, thus negatively affecting the overall sustainability of the wine industry.

Read More

Analysis of peptide fraction from white wines

Among nitrogen compounds included in white wines, the peptide fraction is certainly the least studied, however this fraction is quantitatively the most important (Feuillat, 1974). Existing studies concern the fraction below 1 kDa and only for white and sparkling wines (Bartolomé et al, 1997, Desportes et al 2000). In this report, we have developed methods to isolate peptides from reference white wines. Then, we have applied this methodology with bitter wine to answer a research question: is there a relation between peptides and the bitterness of white wine as for some cheese for example (Furtado, 1984)?

Read More

Mixed starters Schizosaccharomyces japonicus/Saccharomyces cerevisiae as a novel tool to improve the aging stability of Sangiovese wines

In the present work Schizosaccharomyces japonicus and Saccharomyces cerevisiae were inoculated simultaneously or in sequence in mixed fermentation trials with the aim of testing their ability to improve the overall quality of red wine

Read More

PESTICIDE RESIDUES IN THE VINEYARD ENVIRONMENTS: VINE LEAVES, GRAPE BERRIES, WINES, HONEYBEES AND ASIAN HORNETS

Synthetic pesticides are widely used in viticulture to ensure steady harvest quality and quantity. Fungicides are primarily used to control grapevine diseases but insecticides and herbicides are likewise used. Pesticide residues in viticultural areas currently represent a strong societal concern, but may also affect different trophic chains in such areas. In this project we wish to analyse honeybees collected from hives placed in different vineyards, their natural predator (the invasive hornet Vespa velutina), as well as the honey, grape berries, and wines produced.

Read More