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


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.



Publication date: June 22, 2020

Issue: GiESCO 2019

Type: Article


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


Correlation, Heterogeneity, Humidity, Leaf Wetness, local effects 


GiESCO 2019 | IVES Conference Series


Related articles…

Screening of different commercial wine yeast strains: the effect of sugar and copper additions on fermentation and volatile acidity production

The aims of this study were to examine the effect of high sugar concentrations of must and copper residues on different commercial wine yeasts. Copper originating from pesticides has been known to inhibit yeast, but it’s effect on fermentation performance and VA production of different yeast strains had not been investigated in detail.

Green berries on Gewürztraminer (Vitis vinifera L.) in South Tyrol (Italy)

The grape variety Gewürztraminer is known to be affected by two physiological disorders namely berry shrivel and bunch stem necrosis. During the season 2014 we noticed a new symptomatology type of ripening disorder on the variety. The new symptom showed not all berries fallowing the normal maturation stages, but single berries remaining at a soft but green stage till harvest. The broad distribution of these so called “green berries” symptoms in different production sites of our region, caused huge damage due to the difficulty of eliminating single berries per bunch before harvesting. Therefore, the Research Centre Laimburg began to investigate the reasons and origins of this new symptom. This work shows the results of first attempts to find causes for the symptom as well as the resulting approach to mitigate symptoms. Applications of magnesium leaf fertilizer showed first promising results against this putative disorder. To study the causal effect of the green berries 30 symptomatic vineyards in 2014 have been selected for a monitoring during the season 2016. To evaluate the foliar nutrient treatment two vineyards have been selected for application of magnesium sulfate and magnesium chloride. Leaf and berry nutrient analysis, as well as the main quality parameters during ripening have been performed. As soon as “green berries” symptoms appeared, incidence and severity have been evaluated. Most of the symptomatic vineyards of the 2016 monitoring showed light to clear magnesium deficit symptoms on their foliage. Only during the seasons 2020 and 2021 “green berries” symptoms could be found in the leaf fertilizer treatment vineyards. Both seasons showed a significant effect of the magnesium treatments to reduce the incidence and severity of the symptom. It seems that the appearance of the “green berries” symptom on Gewürztraminer is correlated to a disturbed uptake of magnesium of the vines.

Extracellular substances of lactic acid bacteria interests in biotechnological practices applied to enology

Extracellular substances (ECS) represent all molecules outside the cytoplasmic membrane, which are not directly anchored to the cell wall of microorganisms living through a planktonic or biofilm phenotype. They are the high-biomolecular-weight secretions from microorganisms (i.e. extracellular polymeric substances – EPS – proteins, polysaccharides, humic acid, nucleic acid), and the products of cellular lysis and hydrolysis of macromolecules. In addition, some high- and low-molecular-weight organic and inorganic matters from environment can also be adsorbed to the EPS. All can be firmly bound to the cell surface, associated with the EPS matrix of biofilm, or released as being freely diffusing throughout the medium.

The influence of tertiary and quaternary deposits on the viticultural potential of the terroirs to be found in Geneva, Switzerland

The 1365 ha of the Genevese vineyard are located at the south-western corner of the Swiss plateau, between 395m and 505 m altitude.

The role of terroir in tourism led amenity migration: contrasting effects in Tuscany and the Okanagan valley of British Columbia

Definitions of terroir elude consistent agreement. As defined geographical space the common denominators of its conceptualization include natural and cultural elements of life