Terroir 2016 banner
IVES 9 IVES Conference Series 9 Impact of defoliation on leaf and berry compounds of Vitis vinifera L. Cv. Riesling investigated using non-destructive methods)

Impact of defoliation on leaf and berry compounds of Vitis vinifera L. Cv. Riesling investigated using non-destructive methods)

Abstract

Climate change has a strong impact on the earlier onset of important phenological stages and plant development in viticulture. Hence, the adaptation of plant management is important to reply to climate related changes on a seasonal or long-term scale. In particular, a change in precipitation and higher temperatures entails the risk negatively impacting on fruit quality. An experiment was conducted where different canopy management strategies were applied to Riesling grapevines (Vitis vinifera L. cv. Riesling) planted in Winkel (Rheingau, Germany). Leaf removal at different canopy positions using various methods (e.g. manual vs. mechanical defoliation practices) led to a reduced photosynthetic active leaf area. Through modifications of the leaf area to fruit weight ratio, the berry ripening can be altered. Leaf removal of the bunch zone impacts fruit parameter and most importantly fruit health. Four different defoliation practices within a VSP trellis system were compared to a non-defoliated control during three growing seasons in an organic treated site: mechanical defoliation above the canopy (MDC); manually defoliation prior to flowering (DpF); defoliation of the bunch zone past flowering: Bunch zone defoliation (BZD) either suction fan plucking (EB490® Binger Seilzug, Germany) and mechanical defoliation or pulsation jetting of compressed air (DmS) (Siegwald®, Germany). Non-destructive measurements using a polyphenolmeter (Multiplex®3, Force-A, Orsay, France) were performed on leaves and berries to estimate the nutrition and ripening stage.

The chlorophyll index showed the lowest values for BZD and highest for control leaves. Additionally, on-the-go measurements were established to determine leaf components achieving vineyard maps in response to nitrogen or chlorophyll index. Furthermore, the data can be used for zoning the vineyard and harvest based on such mapping. When the severity of Botrytis cinerea was compared to control all treatments showed lower disease pressure (BZD -5.3 %, DpF -3.0 % and DmS -2.3 % respectively). Yield differed between -16 % (MDC), -8% DpF, -1 % (DmS) and +1 % (BZD) compared to the control having the highest (1.4 g) and BZD the lowest (1.1 g) single berry weight with a lower bunch compactness in 2014. Defoliation treatments influence the number of cluster per vine, where the lowest were found for DpF plants, accompanied with the lowest yield per single vine. These results help understanding the canopy characteristics and offer an opportunity to adapt the vineyard management strategies to seasonal changes.

DOI:

Publication date: June 23, 2020

Issue: Terroir 2016

Type: Article

Authors

Susanne TITTMANN, Vanessa STOEBER, Manfred STOLL

Geisenheim University, Department of general and organic viticulture, Von – Lade – Str. 1 D-65366 Geisenheim

Contact the author

Keywords

defoliation, non-invasive determination of leaf components, Multiplex, Plasmopara viticola, Vitis vinifera

Tags

IVES Conference Series | Terroir 2016

Citation

Related articles…

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Soil quality in Beaujolais vineyard. Importance of pedology and cultural practices

A pedological study was carried out from 2009 to 2017 in Beaujolais vineyard, to improve physical and chemical knowledge of soils. It was completed in 2016 and 2017 by the current study, dealing with microbial aspects, in order to build a reference frame for improved advice in soil management. Microbial biomass was measured on representative plots of the six most common soil types identified in Beaujolais and, for each soil type, on plots with different levels of the main impacting parameters: total organic carbon, pH, cation exchange capacity, extractable copper. A total of 59 soil samples were collected. Confirming the results of various trials carried out in Beaujolais over the past 20 years, the results of the present study showed that the soils were still alive, but exhibited a large variability of biological parameters, which appeared dependant on both pedological and anthropic factors. Therefore, a good interpretation of biological parameters and advice for vine growers must rely on a pedologically-based referential with differentiated main driving factors. For example, the control of pH is of primary importance in granitic soils and in no way organic matter addition can improve soil quality if pH is too low. Conversely, in calcareous soils, biological parameters are more directly affected by direct or indirect (cover crops for example) inputs of organic matter. The use of biological parameters, such as microbial biomass, is of great potential value to improve advice on agro-viticultural practices (soil management, fertilization, liming, etc.), basis of a sustainable wine production on fragile soils.

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.

Short-term relationships between climate and grapevine trunk diseases in southern French vineyards

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Co-design and evaluation of spatially explicit strategies of adaptation to climate change in a Mediterranean watershed

Climate change challenges differently wine growing systems, depending on their biophysical, sociological and economic features. Therefore, there is a need to locally design and evaluate adaptation strategies combining several technical options, and considering the local opportunities and constraints (e.g. water access, wine typicity). The case study took place in a typical and heterogeneous Mediterranean vineyard of 1,500 ha in the South of France. We developed a participatory modeling approach to (1) conceptualize local climate change issues and design spatially explicit adaptation strategies with stakeholders, (2) numerically evaluate their effects on phenology, yield and irrigation needs under the high-emissions climate change scenario RCP 8.5, and (3) collectively discuss simulation results. We organized five sets of workshops, with in-between modeling phases. A process-based model was developed that allowed to evaluate the effects of six technical options (late varieties, irrigation, water saving by reducing canopy size, adjusting cover cropping, reducing density, and shading) with various distributions in the watershed, as well as vineyard relocation. Overall, we co-designed three adaptation strategies. Delay harvest strategy with late varieties showed little effects on decreasing air temperature during ripening. Water constraint limitation strategy would compensate for production losses if disruptive adaptations (e.g. reduced density) were adopted, and more land got access to irrigation. Relocation strategy would foster high premium wine production in the constrained mountainous areas where grapevine is less impacted by climate change. This research shows that a spatial distribution of technical changes gives room for adaptation to climate change, and that the collaboration with local stakeholders is a key to the identification of relevant adaptation. Further research should explore the potential of adaptation strategies based on soil quality improvement and on water stress tolerant varieties.