Christophe Gigot

ARVALIS Institut du végétal

In California, angular leaf spot (ALS) is a common disease in strawberry nursery production, and a major concern for nurseries wishing to export plants. As the spatial pattern of a disease can offer insight into pathogen source, mode of dissemination, and how current crop management practices affect epidemic development, an understanding of the spa...

Background and Aims Recent developments in plant disease management have led to a growing interest in alternative strategies, such as increasing host diversity and decreasing the use of pesticides. Use of cultivar mixtures is one option, allowing the spread of plant epidemics to be slowed down. As dispersal of fungal foliar pathogens over short dis...

The use of cultivar mixtures to control foliar fungal diseases is well documented for windborne diseases, but remains controversial for splash-dispersed diseases. To try to improve this strategy, a cultivar mixture was designed consisting of two wheat cultivars with contrasted resistance to Mycosphaerella graminicola, responsible for the rainborne...

Une association de blé tendre alliant variétés sensible et résistante à la septoriose limite les dégâts de la maladie, mais de façon variable selon la pression de la septoriose de l’année. C’est ce qu’ont montré des essais réalisés sur cinq ans par l’INRA sur le site de Grignon.

The efficiency of biological control agents is often affected by local conditions such as low relative humidity (r.h.). This is especially true for mites of the family Phytoseiidae, and particularly for their egg stage. A key issue in biological control is thus to assess the drought tolerance of phytoseiid species that are (or that will be) commerc...

Adaptation of cropping management strategies is necessary to ensure the sustainability of our agriculture, which is facing threats arising from climate change. A methodology is proposed to find out and compare the most promising adaptation strategies in this context considering both biotic and abiotic stresses. A set of pre-selected strategies were...

Zymoseptoria tritici causes a damaging foliar disease on wheat. This hemibiotrophic fungus has an unusually long, symptomless incubation period, during which the pathogen remains in the apoplast at low densities, hidden from the plant’s immune system. Why does Z. tritici have such a long incubation period? Based on ecological theory, we propose tha...

Background and aims: Growing cultivars differing by their disease resistance level together (cultivar mixtures) can reduce the propagation of diseases. Although architectural characteristics of cultivars are little considered in mixture design, they could have an effect on disease, in particular through spore dispersal by rain splash, which occurs...

L’intérêt des associations variétales de blé pour freiner la propagation des maladies dispersées à longue distance par le vent est bien démontré, mais les références sont très limitées concernant les maladies dispersées à courte distance par la pluie. Des essais réalisés sur 5 ans par l’INRA montrent qu’une association de deux variétés de blé, l’un...

Septoria tritici blotch is an important splash-dispersed disease, causing high yield losses in Europe. Plant disease propagation results from spore dispersal and susceptibility of plant tissues. An experiment was performed in order to study differents aspects of the disease dispersal cycle. Three wheat varieties with contrasted resistance levels we...

L'association variétale - c'est-à-dire l'association de différentes variétés d'une même espèce simultanément au sein d'une parcelle agricole - offre la possibilité de diversifier les traits de résistance aux maladies fon- giques et les caractéristiques agronomiques des plantes. Bien conçues, les associations variétales permettent ainsi de mieux maî...

La dispersion par éclaboussement de Mycosphaerella graminicola, agent de la septoriose du blé, dépend à la fois de l’architecture du couvert végétal1 et des caractéristiques de la pluie2. Une expérimentation en conditions contrôlées a été réalisée dans le but de quantifier l’impact d’architectures de blé différentes et de pluies contrastés sur l’in...

A model taking into account physical mechanisms involved in splash dispersal of pathogens and host cultivar quantitative resistance has been developed to study the potential of heterogeneous three-dimensional crop canopies such as cultivar mixtures to prevent disease progression. We investigated different spatial organizations, proportions and resi...

A model taking into account physical mechanisms involved in splash dispersal of pathogens and host cultivar quantitative resistance has been developed to study the potential of heterogeneous three-dimensional crop canopies such as cultivar mixtures to prevent disease progression. We investigated different spatial organizations, proportions and resi...

Accroître la diversité végétale au sein d'une culture par l'utilisation d'associations variétales est une stratégie qui permet de limiter la sévérité des maladies à dispersion éolienne. Les potentialités de cette pratique culturale restent à être caractérisées de manière précise dans le cas des maladies à dispersion pluviale, telle que la septorios...

Accroître la diversité végétale au sein d’une culture par l’utilisation d’associations variétales est une stratégie qui permet de limiter la sévérité des maladies à dispersion éolienne. Les potentialités de cette pratique culturale restent à être caractérisées de manière précise dans le cas des maladies à dispersion pluviale, telle que la septorios...

Increasing plant diversity using cultivar mixtures is a worthwhile strategy that has been shown as a way of reducing wind-borne disease severity on crops and prolonging the efficacy period of plant resistance genes. The relevancy of this cultural practice remains to be assessed in the case of rain-borne diseases, such as septoria tritici blotch. Th...

This poster presents ECHAP project objectives and methods. The ECHAP project is part of the « Evaluation et réduction des risques liés à l’utilisation des pesticides » program of Ministère de l’Ecologie et du Développement Durable. Canopy architecture may influence crop disease epidemics by inducing disease escape. Architecture also influences pes...

SESSION 2.2: Effects of plant and canopy architecture on microclimatic variables and epidemiological processes - Keynote B

Canopy architecture and distances between plant organs sensible to fungal airborne diseases are one of the main factors that are explanatory of the disease epidemics. It has been shown that wheat architecture can modify the progression of Septoria leaf blotch (STB) epidemics within wheat canopy. Disease progression of STB is mainly caused by rain s...

Canopy architecture and distances between organs of plants susceptible to fungal airborne diseases are two factors influencing disease epidemics. It has been shown that wheat architecture can affect the progression of septoria tritici blotch (STB) within the canopy. During the epidemic stage, STB progression is mainly due to rain splash, which indu...

Septoria tritici blotch, caused by the fungus Mycosphaerella graminicola, is the predominant foliar rain-borne disease on wheat crops, and it is regularly responsible for substantial yield losses (up to 40%). In the agricultural context of input reduction, cultivar mixtures have been shown as a way of controlling wind-borne fungal diseases, and the...

Session 5 : Epidemiologie Poster n°5.10

Oral Presentations - Session 5 Cultural Measures and Disease Management

Effect of wheat canopy architecture and rain characteristics in splash dispersal of Mycosphaerella graminicola pycnidiospores

Diplôme : Diplôme d'Ingénieur Agronome