GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Exploring the factors affecting spatio‐temporal variation in grapevine powdery mildew

Exploring the factors affecting spatio‐temporal variation in grapevine powdery mildew

Abstract

Context and purpose of the study ‐ The spatial distribution of powdery mildew is often heterogeneous between neighboring plots, with higher disease pressure in certain places that can be considered as disease “hotspots”. The position of hotspots can vary over the years, even if some plots consistently present a higher vulnerability over time. This spatio‐temporal heterogeneity makes it difficult to obtain accurate prediction by epidemiological models that are fed by meteorological variables coming from weather stations that are not in close proximity to the vineyards or are spatialized over large cell grids. The aim of the project was to explore the role of environmental/agronomic factors involved in powdery mildew pressure variation in time and at the plot and regional scale.

Material and methods ‐ To do so, a series of variables were monitored in 10 different vineyards, in the Beaune region (Bourgogne) of France, over two years. These factors included agronomic descriptors and weather variables. Weather data were acquired at the plot scale. Disease symptoms were observed weekly on leaves and grapes, highlighting inter‐plot variation in disease indicators.

Results ‐ The factors that most impacted this variability were relative humidity, rain, leaf wetness, vigor and phenology. A more in‐depth study of the interactions between these factors will help to disentangle the complex effects of the environment on powdery mildew inter‐plot heterogeneity. Relative humidity and leaf wetness appeared as the most closely correlated variables to powdery mildew onset and pressure. Undoubtedly these results need to be further confirmed and quantified through more extended surveys, but they indicate interesting directions for the improvement of predictive models of powdery mildew.

 

DOI:

Publication date: June 22, 2020

Issue: GiESCO 2019

Type: Article

Authors

Romane MELYON‐DELAGE (1), Benjamin BOIS (2), Sébastien ZITO (2), Mario REGA (2), Guillaume GARIN (1), Amelia CAFFARRA (1)

(1) itk, Cap Alpha, Avenue de l’Europe, 34830 Clapiers, France
(2) CRC, Biogéoscience, Université de Bourgogne Franche Comté, 2 Bld Gabriel, 21000 Dijon, France

Contact the author

Keywords

Correlation, Heterogeneity, Humidity, Leaf Wetness, local effects 

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Effects of auxin treatment on compositional and molecular ripening dynamics in grape varieties of northern Italy

Context and purpose of the study. The temperature increase related to ongoing climate changes is causing a progressive anticipation of the ripening time, negatively affecting grape quality at harvest.

RED WINE AGING THROUGH 1H-NMR METABOLOMICS

Premium red wines are often aged in oak barrel. This widespread winemaking process is used, among others, to provide roundness and complexity to the wine. The study of wine evolution during barrel aging is crucial to better ensure control of wine quality.
¹H-NMR has already been proved to be an efficient tool to monitor winemaking process [1]. Indeed, it is a non-destructive technique, it requires a small amount of sample and a short time of analysis, yet it provides clues about several chemical families.

Extension to the Saumurois-Touraine area of an Anjou-originated method for the characterisation of the viticultural terroirs. (Loire Valley, France)

En Anjou, une méthode de caractérisation des terroirs viticoles a été développée. Elle utilise un modèle de terrain basé sur la profondeur de sol et son degré d’argilisation. Le modèle concerne des terrains issus principalement de roches mères métamorphiques et éruptives du Massif Armoricain. Cet outil de caractérisation des terroirs viticoles nécessite d’être adapté lorsqu’il s’agit d’ensembles géologiques très différents, en particulier sur sols d’apport et de roches mères tendres et poreuses du Bassin Parisien. Une meilleure compréhension de la réserve hydrique des sols apparaît être un critère important de l’interaction entre le milieu et la plante.

Effect of terroir on the quality evolution of Cabernet-Sauvignon in Penedès A.0.C.

Le Cabernet-Sauvignon est un cépage très répandu dans la région du Penedès (Espagne) où cette variété peut bien s’adapter et donne des produits de haute qualité.

Plant fibers in comparison with other fining agents for the re-duction of pesticide residues and the effect on the volitile profile of Austrian white and red wines.

Pesticide residues in Austrian wines have so far been poorly documented. In 250 wines, 33 grape musts and 45 musts in fermentation, no limit values were exceeded, but in some cases high lev-els (>0.100 mg/l) of single residues were found, meaning that a reduction of these levels before bottling could make sense. In the course of this study, a white and a red wine were spiked with a mix of 23 pesticide residues from the group of fungicides (including botryticides), herbicides and insecticides. The influence of the following treatments on residue concentrations and volatile profiles were investigated: two activated charcoal products, a bentonite clay, two commer-cial mixed fining agents made of bentonite and charcoal, two yeast cell wall products, and a plant fiber-based novel filter additive. The results of this study show that all the agents tested reduced both residues and aromavolatile compounds in wine, with activated charcoal having the strongest effect and bentonite the weakest. The mixed agents and yeast wall products showed less aroma losses than charcoal products, but also lower residue reduction. Plant fibers showed good reduction of pesticides with moderate aroma damage, but these results need to be con-firmed under practical conditions.