[PhD’s Corner] Mathilde Chen: Grape downy mildew risk analysis by analysing regional survey data and local expert knowledge

Mathilde Chen is one of the first #DigitAg labeled PhDs

Grape downy mildew risk analysis by analysing regional survey data and local expert knowledge

  • Start Date: january 2017
  • University: Paris Saclay
  • PhD School:   ABIES
  • Field(s): Agronomy, Statistics
  • Doctoral Thesis Advisor:  David Makowski (INRA)
  • Co-supervisor :  François Brun (Acta)
  • Funding: Acta-les instituts techniques
  • #DigitAg: Labeled PhD – Challenge 3 (ICT and crop protection)

Keywords: epidemiosurveillance, risk analysis, vine, plant health, pesticide exposure, plant disease – Downy mildew – grapevine


Plasmopara viticola is the pathogen responsible for downy mildew, considered a major disease of grapevine. Indeed, downy mildew can cause yield and grape quality losses. Fungicides are almost systematically applied to control the disease. One widely recommended control strategy involves a first fungicide application after the end of the incubation period for the first primary infection, corresponding to the date on which the first symptoms appear. This strategy keeps a low level of inoculum in the plot and thus limits the spread of the disease. The date of appearance of the first symptoms is therefore crucial information for the protection of the vineyard. This date partly determines the number of fungicide treatments that will be used during the season to control grape downy mildew and therefore needs to be estimated as accurately as possible.

The distribution of probable dates of appearance of grape downy mildew first symptoms was estimated using two different approaches. The first estimation method is based on survival models to analyze the Epicure database, which consists of epidemiological surveillance data collected by the Institut Français de la Vigne et du Vin in the Bordeaux region. The second method is based on the probabilistic elicitation of a panel of regional experts, solicited in the spring of 2017 and 2018.

The results from these different approaches will be used to estimate different scenarios for reducing the number of mildew fungicide treatments in the Bordeaux region. These scenarios will then be used to estimate the exposure of winegrowers to mildew fungicides based on the date of the first treatment.


Contact:  mathilde.chen [AT] acta.asso.fr ou mathilde.chen [AT]  inra.fr – Tél : +33 1 30 81 59 06 / +33 671419020

Networks : ResearchGateLinkedIn

Communications / Publications

Original articles 

Chen, M., Brun, F., Raynal, M. & Makowski, D., 2018. Timing of grape downy mildew onset in Bordeaux vineyards. Phytopathology. 2018 Oct 30. https://doi.org/10.1094/PHYTO-12-17-0412-R


Chen, M., Brun, F., Raynal, M. & Makowski, D., 2018. Estimer la date d’apparition du mildiou de la vigne grâce à l’élicitation probabiliste d’experts. Végéphyl – 12ème Conférence Internationale sur les Maladies des plantes. Tours, le 11 et 12 décembre 2018.

Brun, François, & Chen, Mathilde, Michel, Lucie, Veslot, Jacques, Makowski, David & al. (2017). Valorisation des données agricoles d’épidémio-surveillance. Création d’outils pour les acteurs régionaux du Bulletin de santé du végétal. VigiCultures, Réfléxions collectives à son évolution, 22 juin 2017, Paris, Acta-INRA – DOI : https://doi.org/10.13140/rg.2.2.36295.60320

Brun, François, Chen, Mathilde, Van de Kerckhove, Simon & al, et. (2017). Epi Agro – Visualiser la santé du blé. Phttps://doi.org/10.13140/rg.2.2.36295.60320résentation du prototype. Pitch au Hackathon Api Agro – SIMA 2017, Paris, DOI :  https://doi.org/10.13140/RG.2.2.28326.42568

Brun, François, Michel, Lucie, Veslot, Jacques, Chen, Mathilde, Makowski, David & al. (2017). Real-time analysis and prediction tools based on data for regional plant health monitoring: application on wheat and wine in France. EFITA 2017, Montpellier (France), July 2nd-6th (European conference dedicated to the future use of ICT in the agri-food sector, bioresource and biomass sector