GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Impact of changing climatic factors on physiological and vegetative growth

Impact of changing climatic factors on physiological and vegetative growth

Abstract

Context and purpose of the study – scientific information on grapevine response to predicted levels of climate parameters is scarce and not sufficient to properly position the Wine Industry for the future. It is critical that the combined effects of increased temperature and CO2 on grapevines should be examined, without omitting the important link to soil water conditions. The purpose of this study is to quantify the effects of envisioned changes in climatic parameters on the functioning and growth of young grafted grapevines under controlled conditions, simulating expected future climate changes. Scientific knowledge of precisely how the newly-planted grapevine will react morphologically, anatomically and physiologically (at leaf, root and whole plant level) to the expected changes in important climatic parameters will enable producers to make better-informed decisions regarding terroir, cultivar and rootstock choices as well as the adaptation of current cultivation practices.

Material and methods – four glass house compartments were set up with combinations of the two main environmental factors, namely ambient temperature and CO2. Within each compartment, another treatment factor, water supply, was introduced. Young, grafted grapevines were established in pots in a randomized block design. Five growth cycles of 12 weeks each were monitored, with Shiraz as scion cultivar in three of them and Merlot in the other two. The rootstock used throughout was 101-14 Mgt. Vegetative and physiological growth parameters were measured throughout the growth cycles with critical sampling times at 4, 8 and 12 weeks after planting.

Results – a change in environmental growth conditions significantly affected physiological activity of the grapevine. Both increased CO2 levels and adequate water supply increased photosynthetic activity for all treatment combinations. Newly planted vines were photosynthetically more active and reacted more strongly to treatments than slightly older vines. The higher temperature treatment seemed to impair photosynthesis under comparable CO2 and H2O conditions, especially with regards to very young vines. The effect of temperature on vegetative growth was insignificant compared to the CO2 and H2O effects and only seemed to affect initial growth directly after planting. The availability of water was critical to root, shoot and leaf growth – higher CO2 levels further enhanced vegetative growth.
The results indicate that the importance and impact of the climatic variables and the vine reaction change during the growth season. The strong interactions found between weeks after planting, available water, ambient temperature and CO2 levels necessitate multi-variable research on the effect of changing climatic factors on the grapevine.

DOI:

Publication date: March 11, 2024

Issue: GiESCO 2019

Type: Poster

Authors

H. THERON 1,2*, C.G. VOLSCHENK 3, J.J. HUNTER 3

1 Cape Peninsula University of Technology (CPUT), Wellington, South Africa
2 University of Stellenbosch (US), Stellenbosch, South Africa
3 ARC Infruitec-Nietvoorbij, Stellenbosch, South Africa

Contact the author

Keywords

Climate change, Grapevine, CO2, Temperature; Water deficit, Growth, Physiology

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Identifying wild Vitis riparia Michx clones as a source of rootstock to mitigate vigour and acclimation/deacclimation cycles of the scion

Grapevine rootstocks have traditionally been chosen in order to manage scion vigour, soil pests and soil conditions. Riparia Gloire de Montpellier (RGM) has been in use since the turn of the 19th century, over 100 years and still a remarkably stable source of phylloxera (Daktulosphaeria vitifoliae Fitch) resistance. The original source material was probably collected near the Missouri/Mississippi river confluence, a mid-continental but more southerly location in the United States. It has been hypothesized that more northerly selections of V. riparia Michx might improve both fall acclimation rate and depth of the scion, thus mitigating late fall frost and midwinter freeze damage.

Composition and biological potential of grape and wine phenolic compounds

Polyphenols are common in human diets, primarily in plant-derived food and beverages. They influence multiple sensory properties such as aroma, flavour, colour, and taste, such as astringency and bitterness [1]. The major phenolic compounds in grapes and wines are anthocyanins and tannins (proanthocyanidins or condensed tannins).

White wine lees: unlocking the relationship between chemical composition and antioxidant potential

The wine-making process generates numerous by-products at each stage (crushing, fermentation, ageing), including wine lees, which account for almost 25% of the total quantity.

Evaluation of mannoprotein formation by different yeast strains by enzymatic analysis of mannose and tribological estimation of astringency

A positive role of mannoproteins on wine stability and red wine mouth sensations has been widely described. Commercial mannoproteins are available and some yeast strains are offered with a higher formation of mannoproteins.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.