GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Characterisation of berry shrivel in Vitis vinifera L. Cultivars in the Stellenbosch wine region

Characterisation of berry shrivel in Vitis vinifera L. Cultivars in the Stellenbosch wine region

Abstract

Context and purpose of the study – Late season dehydration, bunch stem necrosis, sugar accumulation disorder and sunburn are various types of berry shrivel occurring in vineyards. The incidence of these types of shrivel, and the degree to which it occur are influenced by various factors in the vineyard. These factors include the presence of pests and diseases in the vineyard, genetic traits expressed in certain cultivars, as well as climatic and environmental factors. The occurrence of berry shrivel in the vineyard could negatively impact the quality and quantity of the fruit produced. The aim of this study was to visually characterise the different types of berry shrivel occurring and the corresponding in two cultivars Vitis vinifera L. Chenin blanc and Shiraz in the Stellenbosch Wine region.

Material and methods – In this study the occurrence of berry shrivel in Chenin blanc and Shiraz grapes were studied in two vineyards in the Stellenbosch Wine of Origin district during the 2017/2018 ripening season. Two distinct microclimates were established by implementing a leaf removal treatment in the bunch zone of the canopies on the morning side of some of the experimental panels around véraison, leading to a more exposed microclimate (leaf removal treatment) versus untreated control panels. To confirm microclimatic impacts, loggers were placed in the vineyards to measure the temperatures in the bunch zone of the control and treatment panels. Additionally, grape composition (berry fresh weight, berry volume, total soluble solids, pH and TA was monitored during the growing season for each of the grape cultivars.

Results – Bunches on vines where leaves were removed were exposed to more direct sunlight and temperature extremes, hence sunburn‐related berry shrivel was induced in these vines, especially in the Chenin blanc cultivar. Other types of berry shrivel were however also identified in both cultivars to various degrees during the ripening season, but late stage dehydration also occurred in both cultivars at the overripe stage. It was possible to visually follow the progress of shrivelling throughout the season and a grading scale was implemented to calculate the affected bunch areas. Slight differences were observed in the grape composition of the control (shaded) and exposed (treatment).

Download the PDF

DOI:

Publication date: September 27, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Erna BLANCQUAERT1

1Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa

Contact the author

Keywords

berry shrivel, dehydration, necrosis, sunburn

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

INFLUENCE OF GRAPE RIPENESS ON MACROMOLECULES EXTRACTABILITY FROM GRAPE SKIN TISSUES AND GRAPE SEEDS DURING WINEMAKING

A consequence of climate change is the modification of grape harvest quality and physico-chemical parameters of the obtained wine: increase in alcoholic degree, decrease in pH, and modification of the extractability of macromolecules, which leads to problems of microbiological, tartaric, colour and colloidal stability. In order to respond to these problems, the winemaking processes must be anticipated and adapted with a better knowledge of macromolecule extractability in grapes and their evolution, according to the grape variety, vintage and winemaking process. The purpose of this study was to understand 1) how the harvest date can influence the extractability of macromolecules, polysaccharides and phenolic compounds, which are responsible for wine stability 2) how to adapt the winemaking process to the harvest date in order to optimise wine quality.
Read More

Water and physiological response to early leaf removal of cv. Verdejo in rainfed conditions, at different times of the day, in the D.O. Rueda (Spain)

Aim: Early leaf removal, generally applied before flowering, is mostly conceived as a technique to control grape yield and improve the health of grapes and focused on the final objective of increasing wine quality.

Read More

Under-vine management effects on grapevine vegetative growth, gas exchange and rhizosphere microbial diversity

The use of cover crops under the vines might be an alternative to the use of herbicides or tillage, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management strategies of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status, gas exchange parameters and belowground microbial communities.
The experimental design consisted in 4 treatments applied on 35L-potted Tempranillo vegetative grapevines with 10 replicates each grown in an open-top greenhouse in 2022 and 2023. Treatments included two cover crop species (Trifolium fragiferum and Bromus repens), herbicide (glyphosate al 36%) and an untreated control.

Read More

Influence of short-time skin maceration combined with enzyme treatment on the volatile composition of musts from fresh and withered fiano winegrapes

AIM: The increasing market competitiveness is promoting the production of special dry wines with distinctive characteristics, obtained either from minor winegrape varieties and/or the inclusion of partially dehydrated grapes.

Read More

Use of cyclodextrins to improve grape must fermentability thanks to their sequestering effect on medium-chain fatty acids

Cyclodextrins are complex cyclic oligosaccharides of glucose units. They are produced from the breakdown of starch by the enzymatic reaction of glucosyltransferase. The result is a ring-shaped molecule with a cavity with a hydrophilic outer part and a hydrophobic inner part. As a consequence of this cavity, cyclodextrin is able to form complexes with non-polar organic molecules [1,2].

Read More