Terroir 2020 banner
IVES 9 IVES Conference Series 9 Regulated deficit irrigation and crop load interaction effects on grape heterogeneity

Regulated deficit irrigation and crop load interaction effects on grape heterogeneity

Abstract

Aim: To investigate the interaction effects between irrigation and crop load and the resulting impact on grape heterogeneity within a Geographical Indication in South Australia. 

Methods and Results: Cabernet Sauvignon grapes were sampled at the time of harvest from the Coonawarra Geographical Indication where full and sustained deficit irrigation and crop load manipulations were implemented as a 2 × 2 factorial block design. Grape heterogeneity was quantified for each treatment at three levels (bunch, vine and block) using berry density categories that were related to grape maturity. Furthermore, each density category was characterised in terms of total soluble solids, berry fresh weight, tannin content and tartaric and malic acid concentrations. Irrigation and crop load interaction effects on grape heterogeneity were observed for intra- cluster, vine, and between blocks.

Conclusion: 

This research reveals the extent of heterogeneity existing in the vineyard at the time of harvest, and presents management techniques that may mitigate grape ripeness variation in the vineyard.

Significance and Impact of the Study: Grape heterogeneity is an important consideration for the production of high quality red wine, as high proportions of under ripe and/or overripe fruit present at the time of harvest have been shown to negatively impact colour, mouthfeel, and varietal aroma of the wine. Furthermore, the presence of overripe/shrivelled grapes with excessive sugar concentrations can lead to increased ethanol in the wine. Previous research has acknowledged the impact that the three focal aspects of terroir – climate, soil and cultivar – have on grape composition, with the overarching effects of climate being highlighted. Vine water status and vine balance can conceivably mediate some of the influences of climate on grape composition, but there has been limited literature delving into the effects on grape heterogeneity. By investigating vineyard management techniques with a view to minimising grape heterogeneity, this research gives insight into the optimisation of grape production, especially in hotter climates that are more susceptible to producing overripe fruit.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type: Video

Authors

Claire Armstrong1,2, Pietro Previtali1,2, Vinay Pagay1,2, Paul Boss1,3, David Jeffery1,2*

1 ARC Training Centre for Innovative Wine Production, The University of Adelaide, PMB 1 Glen Osmond, SA, 5064, Australia
2 The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA, 5064, Australia
3 CSIRO Agriculture and Food, Locked Bag 2, Glen Osmond, SA 5064, Australia

Contact the author

Keywords

Vineyard management techniques, vineyard variation, grape composition, Cabernet Sauvignon, red wine quality

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Influence of planting stock and training strategy on the development and productivity of Pinot noir grapevines

For cool windy climates and/or lower vigor site situations delays in vine development during vine establishment can result in a greater number of growing seasons to achieve full yield potential. Plant material and training strategies utilized are critical factors in promoting vine development and production that is appropriate to the site conditions. The objective of this study was to evaluate nursery planting stock and training strategies for their potential to achieved advanced vine development and yield.

WINE FERMENTATION METABOLITES PRODUCED BY TWO TORULASPORA DELBRUECKII STRAINS ISOLATED FROM OKANAGAN VALLEY, BC, CANADA VINEYARDS

Wine aroma is influenced by various factors, from agricultural practices in the vineyard to the enological choices made by winemakers throughout the vinification process. Spontaneous fermentations have a characteristically deeper complexity of aromas when compared to fermentations that have been inoculated with Saccharomyces (S.) cerevisiae because of the diversity of microflora naturally present on grape skins. Non-Saccharomyces yeast are being extensively studied for their ability to positively contribute to wine aroma and flavour. These yeasts are known to liberate more bound volatile compounds present in grape must than S. cerevisiae through the enzymatic action of β-glucosidases and β-lyases1.

Shoot heterogeneity effects in a Shiraz/R99 vineyard

Nous avons fait des recherches sur l’effet de l’hétérogénéité des bourgeons sur les paramètres de la croissance végétative et reproductive, la physiologie de la vigne et la composition du raisin dans une parcelle de Shiraz/Richter 99. Des bourgeons sous-développés (typiquement plus courts et moins mûrs à la véraison) ont été comparés avec

Application of treatments to delay the ripening of grape varieties cultivated in valpolicella

Winegrape cultivars are particularly sensitive to temperature and recent changes in climate have advanced the onset of berry ripening, resulting in unbalanced fruit composition at harvest.

Volatile Organic Compound markers of Botrytis cinerea infection in artificially inoculated intact grape berries

The addition of partially dehydrated grapes to enrich must composition for producing complex dry/sweet wines represents a traditional practice in several regions of the world. However, the environmental conditions of dehydration chambers may facilitate the infection of Botrytis cinerea Pers. by promoting disease and provoking large grape losses. B. cinerea attack can induce alterations in the profile of volatile organic compounds (VOCs), which could be detected by sensors specifically trained to detect infection/disease-related compounds. These sensors could facilitate the early detection of the infection, consequently allowing to adjust some dehydration parameters.