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Ce volume regroupe les textes issus du programme Casdar "Innovation et Partenariat" et "Recherche technologique" de 2016. Il a été réalisé sous l’égide du GIS Relance Agronomique.; Several management methods for phytophagous bugs on tomato, eggplants and cabbage crops wereevaluated during the research program IMPULsE (2017-2020). In addition, a huge work was carried outfor characterization of the species of bugs present, in order to better understand and to be able to correctlyidentify these highly problematic pests in vegetable crops. In parallel, a study aimed at characterizing thenatural diversity of bug parasitoids was carried out, which succeeded in identifying natural enemies andpotential biological control agents. At this stage, management methods based on physical protection(nets, chromatic sticky traps) and biological control (parasitoids, entomopathogenic nematodes) gave themost interesting results in tomato and eggplant crops under cover. The use of trap plants showed a real potential in cultivation for the management of cabbage bugs in the field. At the end of the project, variousmanagement levers were identified, but the overall strategies remain to be refined.; Le projet IMPULsE (2017-2020) a permis d’évaluer plusieurs méthodes de gestion des punaisesphytophages sur cultures de tomate, aubergine et chou. De plus, un travail important de caractérisationdes espèces de punaises présentes a été conduit afin de mieux connaître et d’être en mesure d’identifiercorrectement ces ravageurs très problématiques en culture. En parallèle, une étude visant à caractériserla diversité naturelle des parasitoïdes de punaises a été réalisée, permettant ainsi d’identifier les ennemisnaturels et de potentiels agents de lutte biologiques. A ce stade, les méthodes de gestions basées sur laprotection physique (filets, pièges chromatiques englués) et la lutte biologique (parasitoïdes, nématodesentomopathogènes) donnent les résultats les plus intéressants en culture de tomate et d’aubergines sousabris. L’utilisation de plantes pièges montre un réel intérêt en culture pour la gestion des punaises duchou en plein champ. A l’issue du projet, différents leviers de gestion ont été identifiées, cependant lesstratégies globales restent à affiner.

International audience; Current restrictions on the use of chemical nematicides have led to an increase in root-knot nematode (RKN) damages in horticultural crops. The effects of two sorghums as summer cover crops, Sorghum sudanense sudan-grass cv. ‘Piper’ or sudangrass hybrid [S. bicolor x S. sudanense] ‘270911’, respectively with low and high dhurrin contents, were compared in their ability to suppress RKN in a vegetable production system. The use of both sorghums ‘Piper’ and ‘270911’ as a green manure was found to be an effective strategy for decreasing RKN infestation in the soil, thereby protecting the subsequent planting of RKN susceptible crops (chard, lettuce or melon). Analytical experiments were further conducted in growth chamber and greenhouse pot experiments to investigate and compare the susceptibility of the sorghums and the factors affecting their efficacy for RKN management, in order to better explain the results obtained in the field trial. The two sorghums were poor hosts of RKN, acted as trap crops and as a biofumigant releasing hydrogen cyanide. Time of planting, time of bio-fumigation, and type of soil affected their efficacy for RKN management. For best RKN suppression, the sorghum cover crops need to be cultivated during one month or less and biofumigated for one month prior to crop planting. The trapping effect of both sorghums in clayey soil was less efficient than in sandy or sandy-loamy soils. Combining less than 30-days of sorghum culture and 10-days soil incorporation with solarization mulch was particularly efficient in suppressing nematodes. No effect relative to the sorghum type was detectable as long as they were used appropriatel.

International audience; Plant-parasitic nematodes (PPN) are detected everywhere as mixed-species communities. Most non-chemical control strategies of PPN only target some species, thus raising questions about the consequences that this specificity may have on the residual community. In this respect, the long-term ecological sustainability of such strategies is challenged. In order to evaluate the impacts of agronomical practices on PPN communities, two four-year experiments that differed by the presence or absence of root-knot nematodes (RKN - Meloidogyne spp.) were carried out under cold shelters in the south of France, under native field conditions of vegetable cropping systems that included a nematicidal sorghum green manure and a pepper variety carrying a RKN resistance gene. At the site with RKN, RKN populations developed on susceptible vegetables. They were controlled by the green manure but not by the R-pepper, and were also vulnerable to low soil temperatures. At the site without RKN, Paratylenchidae populations developed on susceptible vegetables, but were controlled by both the green manure and the R-pepper, and not by low temperatures. At each site, populations of Telotylenchidae exhibited dynamics suggesting competition with RKN or Paratylenchidae. Hypotheses about competition models are discussed according to the specific life traits of the PPN involved, including ecto- vs. endoparasitism and sedentary vs. free-living behaviour, and to the antagonist mechanisms of the cover and resistant crops that must be introduced in vegetable cropping systems.

Description du sujet. Une approche système basée sur la co-conception et l’évaluation expérimentale in situ de prototypes de systèmes de culture (SDC) a été mise en œuvre dans le projet INRA « GeDuNem » pour une gestion durable des nématodes à galles (NG) dans les systèmes maraîchers sous abris.Objectifs. Il s’agissait (i) d’évaluer pendant quatre ans diverses stratégies de culture combinant résistances génétiques et pratiques culturales (rotations culturales incluant des plantes sensibles, résistantes et non-hôtes, gestion de l’interculture avec couvert végétal nématicide ou solarisation) pour réduire les populations de NG dans le sol et augmenter la durabilité des résistances variétales à ces bioagresseurs, (ii) d’étudier leur impact sur les communautés de nématodes rencontrées et (iii) d’évaluer l’acceptabilité des nouveaux SDC par les agriculteurs.Méthode. Trois prototypes de SDC, co-conçus entre acteurs de la recherche et ceux du développement, ont été comparés à des SDC appliqués classiquement en région méditerranéenne et évalués grâce à des dispositifs complémentaires : (i) expérimentations-système sur trois sites de producteurs du Sud de la France ; (ii) expérimentations analytiques pour approfondir les mécanismes d’action des leviers mobilisés ; (iii) enquêtes pour évaluer l’acceptabilité des prototypes par les agriculteurs. Résultats. Les trois SDC se sont révélés efficaces (90 % de réduction des NG, protection des Solanaceae à résistance partielle, pas d’effet négatif sur les nématodes non phytoparasites) et durables lorsque les conditions d’application et les équilibres biologiques du sol étaient favorables (nématofaune totale diversifiée et abondante). Leur degré d’acceptabilité dépendait du type d’exploitation et de la sensibilité des agriculteurs face à l’innovation.Conclusions. Ces nouveaux SDC doivent encore être améliorés, en interaction avec les producteurs, tant en termes d’efficacité, par l’introduction de nouveaux leviers agroécologiques, que de cout. Les recherches futures devront aussi s’ouvrir à la gestion plus globale de la santé des sols., Design and assessment of innovative Mediterranean vegetable cropping systems to manage root-knot nematodes Description of the subject. A system approach based on co-design and experimental field evaluation of cropping systems (CSs), combining technical and varietal innovations, has been implemented for sustainable management of root-knot nematodes (RKN) in Mediterranean sheltered vegetable systems.Objectives. Cropping systems combining genetic resistance and cultural practices (crop rotations including susceptible, resistant, and non-host plants; intercropping management with nematicidal cover crops or soil solarization) were assessed over a period of 4 years (i) to reduce RKN populations and increase the durability of varietal resistances, (ii) to study the impact of these systems on soil ecology (plant-parasitic and free-living nematode communities), and (iii) to evaluate their acceptability by farmers.Method. Three CS prototypes, resulting from a co-design process with research and development stakeholders, were compared with CSs conventionally implemented in the Mediterranean region. The three prototypes were also evaluated using complementary methods: (i) system experiments in three commercial farms in Southern France; (ii) analytical experiments to decipher the mechanisms of action for some [agroecological??] levers; (iii) surveys to evaluate the acceptability of the prototypes by farmers.Results. All three CSs were found to be effective (90% RKN decrease, protection of partially resistant Solanaceae, no negative effect on non-phytoparasitic nematodes) and sustainable, when application conditions and soil biological equilibrium were favorable (global soil nematofauna diversified and abundant). The acceptability of the three systems depended on the type of farm where they were implemented and the attitude of the farmers towards innovation.Conclusions. These three CSs still need to be improved, in terms of their efficiency, in consultation with participating farmers, by introducing new agroecological levers, as well as innovation costs. Future research will also need to open up to a more comprehensive management of soil health.

Ce numéro est constitué d’articles de synthèse des projets DEPHY EXPE publiés à l’occasion du Colloque National DEPHY EXPE, qui s’est déroulé le 28 mai 2019 à l'Assemblée Permanente des Chambres d'Agriculture (Paris).; Sheltered strawberry production is confronted with a significant diversity of aerial pests, which requires alarge number of phytosanitary interventions. The objective of this project is to offer to strawberryproducers an global strategies, allowing a reduction of at least 50% of the chemical Frequency ofTreatment Index (FTI), reliable and technically realistic. In order to identify these strategies, named"DEPHY", on the 6 years of the project and the 5 sites, on all strawberry pests, strategies combiningbiocontrol solutions (beneficials and biocontrol products) and products phytosanitary measures havebeen evaluated in comparison with a producer reference strategy. The objective of 50% reduction of thechemical FTI was reached in 75% of the cases on early culture (Gariguette variety) and in 50% of thecases on everbearer’s (Charlotte variety). With regard to commercial yields, on average over the 6years of the project, there was no difference in yield between the DEPHY plots and the reference plots.The cost of the DEPHY strategies from 2013 to 2018, is higher than the reference strategy, on average6.4 times on Gariguette and 4.4 times on Charlotte. The biocontrol strategies implemented in thisproject have led to the evaluation of numerous biocontrol beneficials and products. Results of theseevaluations do not make it possible to propose reliable alternative strategies for all strawberry pests (inparticular aphids and powdery mildew). Nevertheless, the technical and economic performances of thestrategies have been progressed.

National audience; Design and assessment of innovative Mediterranean vegetable cropping systems to manage root-knot nematodes Description of the subject. A system approach based on co-design and experimental field evaluation of cropping systems (CSs), combining technical and varietal innovations, has been implemented for sustainable management of root-knot nematodes (RKN) in Mediterranean sheltered vegetable systems.Objectives. Cropping systems combining genetic resistance and cultural practices (crop rotations including susceptible, resistant, and non-host plants; intercropping management with nematicidal cover crops or soil solarization) were assessed over a period of 4 years (i) to reduce RKN populations and increase the durability of varietal resistances, (ii) to study the impact of these systems on soil ecology (plant-parasitic and free-living nematode communities), and (iii) to evaluate their acceptability by farmers.Method. Three CS prototypes, resulting from a co-design process with research and development stakeholders, were compared with CSs conventionally implemented in the Mediterranean region. The three prototypes were also evaluated using complementary methods: (i) system experiments in three commercial farms in Southern France; (ii) analytical experiments to decipher the mechanisms of action for some [agroecological??] levers; (iii) surveys to evaluate the acceptability of the prototypes by farmers.Results. All three CSs were found to be effective (90% RKN decrease, protection of partially resistant Solanaceae, no negative effect on non-phytoparasitic nematodes) and sustainable, when application conditions and soil biological equilibrium were favorable (global soil nematofauna diversified and abundant). The acceptability of the three systems depended on the type of farm where they were implemented and the attitude of the farmers towards innovation.Conclusions. These three CSs still need to be improved, in terms of their efficiency, in consultation with participating farmers, by introducing new agroecological levers, as well as innovation costs. Future research will also need to open up to a more comprehensive management of soil health.; Description du sujet. Une approche système basée sur la co-conception et l’évaluation expérimentale in situ de prototypes de systèmes de culture (SDC) a été mise en œuvre dans le projet INRA « GeDuNem » pour une gestion durable des nématodes à galles (NG) dans les systèmes maraîchers sous abris.Objectifs. Il s’agissait (i) d’évaluer pendant quatre ans diverses stratégies de culture combinant résistances génétiques et pratiques culturales (rotations culturales incluant des plantes sensibles, résistantes et non-hôtes, gestion de l’interculture avec couvert végétal nématicide ou solarisation) pour réduire les populations de NG dans le sol et augmenter la durabilité des résistances variétales à ces bioagresseurs, (ii) d’étudier leur impact sur les communautés de nématodes rencontrées et (iii) d’évaluer l’acceptabilité des nouveaux SDC par les agriculteurs.Méthode. Trois prototypes de SDC, co-conçus entre acteurs de la recherche et ceux du développement, ont été comparés à des SDC appliqués classiquement en région méditerranéenne et évalués grâce à des dispositifs complémentaires : (i) expérimentations-système sur trois sites de producteurs du Sud de la France ; (ii) expérimentations analytiques pour approfondir les mécanismes d’action des leviers mobilisés ; (iii) enquêtes pour évaluer l’acceptabilité des prototypes par les agriculteurs. Résultats. Les trois SDC se sont révélés efficaces (90 % de réduction des NG, protection des Solanaceae à résistance partielle, pas d’effet négatif sur les nématodes non phytoparasites) et durables lorsque les conditions d’application et les équilibres biologiques du sol étaient favorables (nématofaune totale diversifiée et abondante). Leur degré d’acceptabilité dépendait du type d’exploitation et de la sensibilité des agriculteurs face à l’innovation.Conclusions. Ces nouveaux SDC doivent encore être améliorés, en interaction avec les producteurs, tant en termes d’efficacité, par l’introduction de nouveaux leviers agroécologiques, que de cout. Les recherches futures devront aussi s’ouvrir à la gestion plus globale de la santé des sols.

Ce numéro comprend les articles correspondant aux présentations du Colloque Casdar 2018; Originally from Asia, Drosophila suzukii was identified in France in 2010 and causes severe damage tovarious fruit species such as cherry, strawberry and raspberry, destabilizing these sectors. The aim ofthe Casdar project (2013-2016) was to maintain production in these crops by providing knowledge on D.suzukii as well as short, medium and long-term solutions, meeting technical, economic andenvironmental requirements. This project, with the contribution of all partners, provided knowledge onthe biology and behaviour of D. suzukii. The effectiveness of control strategies has been assessed, andfor some methods, technical and economic references were provided. Mass trapping did not appear tobe effective; however, preventive measures have demonstrated to be effective (aeration of crops,management of weed and organic crop waste), as well as the use of nets.; Originaire d’Asie, Drosophila suzukii a été identifiée en France en 2010 et cause des dégâts trèsimportants sur différentes espèces fruitières, telles que les cerises, les fraises et les framboises, allantjusqu’à déstabiliser certaines filières. Le projet Casdar (2013-2016) avait pour enjeu de permettre lemaintien de la production dans les filières concernées en apportant des connaissances sur D. suzukii etdes solutions à court, moyen et long terme, répondant à des exigences fortes sur les plans technique,économique et environnemental. Ce projet, avec la participation de tous les partenaires sur différentssites d’étude, a permis d’acquérir des connaissances sur la biologie et le comportement de D. suzukii.L’efficacité de stratégies de protection a pu être évaluée et pour certaines méthodes, des référencestechnico-économiques ont été fournies. Le piégeage massif n’a pas semblé efficace, cependant laprophylaxie a démontré son efficacité (aération des cultures, gestion de l’enherbement et des déchetsde culture), de même que l’utilisation de filets.

En production maraîchère, un cortège varié de bioagresseurs telluriques induit des dégâts importants occasionnant de lourdes pertes économiques pour les exploitations. Face aux enjeux de réduction de l’usage des produits phytopharmaceutiques et de préservation de la production maraîchère, il est nécessaire d’apporter une réponse systémique en concevant des stratégies adaptées aux contextes technico-économiques locaux. Le projet GEDUBAT (Innovations techniques et variétales pour une Gestion Durable des BioAgresseurs Telluriques dans les systèmes maraîchers sous abris) vise à concevoir et évaluer différents systèmes de culture ayant peu ou pas recours aux traitements chimiques pour gérer les champignons pathogènes du sol et les nématodes à galles. Cet article présente le réseau d’expérimentation des 19 systèmes de culture maraîchers sous abri, conçus par combinaison de pratiques améliorantes pour lutter contre les bioagresseurs telluriques puis testés dans six sites entre 2012 et 2017. Une 1ère approche par analyse multivariée basée sur la fréquence d’usage des leviers permet de faire émerger, indépendamment des sites, quatre groupes de systèmes analogues (clusters) suggérant des approches stratégiques contrastées. L’évolution des indicateurs clés tels que l’IFT est présentée à l’échelle de ces groupes de systèmes. Les enseignements quant aux stratégies testées et les perspectives sont ensuite discutés par les auteurs, In protected vegetable systems, a large range of generalist soil-borne pests and diseases cause important damages on crops leading to heavy economical losses for farmers. Considering the challenge of decrease the pesticides use without altering vegetable productions under shelter, a systemic approach is required to design suitable strategies to their local economical and technical context. The GEDUBAT project is a French network built to test sets of innovative practices for soil-borne diseases and root-knot nematodes sustainable management in protected vegetables systems. A network of six experimental sites has been implemented supporting the design and assessment of different cropping systems using few or no fungicide nor nematicide for soil-borne pests and diseases. This article presents the 19 protected vegetable cropping systems (walk-in tunnels or plastic greenhouses). They were designed to combine promising and alternative practices and were tested in farms or experimental stations from 2012 to 2017. Multivariate analyses of the collected data based on the usage frequency of[br/] each practice were performed. Thus, regardless the experimental site, four groups of similar systems were identified (clusters), suggesting four contrasted strategies. The temporal evolution of key assessment indicators such as the Frequency Treatment Index (FTI) is presented using those four clusters of systems. The first lessons regarding the tested strategies and the perspectives for further research and experiment are addressed.

Ce numéro est constitué d’articles de synthèse des projets DEPHY EXPE publiés à l’occasion du colloque national DEPHY, qui s’est déroulé les 13 et 14 novembre 2018 à la Cité des Sciences et de l'Industrie (Paris). Nous vous invitons à découvrir le bilan et les enseignements des 21 projets conduits sur la période 2012-2017.; National audience; In protected vegetable systems, a large range of generalist soil-borne pests and diseases cause important damages on crops leading to heavy economical losses for farmers. Considering the challenge of decrease the pesticides use without altering vegetable productions under shelter, a systemic approach is required to design suitable strategies to their local economical and technical context. The GEDUBAT project is a French network built to test sets of innovative practices for soil-borne diseases and root-knot nematodes sustainable management in protected vegetables systems. A network of six experimental sites has been implemented supporting the design and assessment of different cropping systems using few or no fungicide nor nematicide for soil-borne pests and diseases. This article presents the 19 protected vegetable cropping systems (walk-in tunnels or plastic greenhouses). They were designed to combine promising and alternative practices and were tested in farms or experimental stations from 2012 to 2017. Multivariate analyses of the collected data based on the usage frequency of each practice were performed. Thus, regardless the experimental site, four groups of similar systems were identified (clusters), suggesting four contrasted strategies. The temporal evolution of key assessment indicators such as the Frequency Treatment Index (FTI) is presented using those four clusters of systems. The first lessons regarding the tested strategies and the perspectives for further research and experiment are addressed.; En production maraîchère, un cortège varié de bioagresseurs telluriques induit des dégâts importants occasionnant de lourdes pertes économiques pour les exploitations. Face aux enjeux de réduction de l’usage des produits phytopharmaceutiques et de préservation de la production maraîchère, il est nécessaire d’apporter une réponse systémique en concevant des stratégies adaptées aux contextes technico-économiques locaux. Le projet GEDUBAT (Innovations techniques et variétales pour une Gestion Durable des BioAgresseurs Telluriques dans les systèmes maraîchers sous abris) vise à concevoir et évaluer différents systèmes de culture ayant peu ou pas recours aux traitements chimiques pour gérer les champignons pathogènes du sol et les nématodes à galles. Cet article présente le réseau d’expérimentation des 19 systèmes de culture maraîchers sous abri, conçus par combinaison de pratiques améliorantes pour lutter contre les bioagresseurs telluriques puis testés dans six sites entre 2012 et 2017. Une 1ère approche par analyse multivariée basée sur la fréquence d’usage des leviers permet de faire émerger, indépendamment des sites, quatre groupes de systèmes analogues (clusters) suggérant des approches stratégiques contrastées. L’évolution des indicateurs clés tels que l’IFT est présentée à l’échelle de ces groupes de systèmes. Les enseignements quant aux stratégies testées et les perspectives sont ensuite discutés par les auteurs

revue en ligne; National audience; Lactuca germplasm was evaluated by testing young plants in laboratory with Meloidogyne incognita. After inoculation with 400 juveniles (J2) per pot, the number of egg masses per plant was used to identify resistant accession. No accession among the 569 tested was immune. But 3% out of 409 L. sativa cultivars and 54% out of 160 wild Lactuca accessions exhibited less than 10 egg masses per plant and were selected as resistant accessions. Resistance of 52 out of the 102 resistant accessions screened on two plants was checked in three laboratories with two isolates; 14 cultivars and 36 L. serriola accessions confirmed low egg mass numbers. Few from these accessions were also resistant (height L. serriola) or partly resistant (PI 419140) to M. arenaria in laboratory. After a strong inoculation (2000 J2/plant), the high level of resistance of four accessions of L. serriola was confirmed. Moreover, 10 resistant accessions were tested in two agricultural soils contaminated with Meloidogyne populations especially M. arenaria. On six L. serriola which were resistant to M. incognita and M. arenaria in laboratory, egg mass number and number of eggs per gall were low in comparison with L. serriola control susceptible to M. arenaria in laboratory. But, the lowest numbers of galls and of egg masses were found on one L. virosa susceptible to M. arenaria in laboratory. In conclusion, some useful accessions were identified for lettuce breeding program for resistance to nematodes.; Une collection de Lactuca a été évaluée pour son comportement vis-à-vis de Meloidogyne incognita, par des tests en laboratoire, sur jeunes plantes en pots inoculées avec 400 larves au stade J2. La sélection des accessions résistantes a été effectuée d’après le nombre de pontes par plante après un cycle de développement des nématodes. Parmi les 569 accessions étudiées aucune n’a été immune. Cependant, parmi 409 variétés de laitue, 3% se sont révélées peu sensibles avec de nombreuses galles mais très peu de pontes ; parmi les 160 accessions de Lactuca sauvages, 54% étaient résistantes car, bien que portant des galles, l’ensemble du système racinaire avait moins de 10 pontes par plante. Le criblage réalisé sur deux plantes par accession a permis de retenir 102 accessions. Des contrôles plurilaboratoires de 52 de ces accessions avec deux souches ont confirmé la grande majorité des résultats avec 14 variétés de laitue et 36 L. serriola résistantes. Parmi ces accessions, quelques-unes étaient également résistantes (huit L. serriola) ou peu sensibles (PI 419140) à M. arenaria en laboratoire. De plus, un test avec une forte pression d’inoculation (2000 J2/plante) a confirmé le haut niveau de résistance des quatre L. serriola évaluées. Par ailleurs, 10 accessions ont été testées en pots vis-à-vis de populations de Meloidogyne de deux sols agricoles de Provence naturellement contaminés, en particulier par M. arenaria ; sur six L. serriola résistantes en laboratoires à M. incognita et M. arenaria, le nombre de pontes ainsi que le nombre de pontes par galle étaient réduits, par rapport aux témoins L. serriola sensibles à M. arenaria en laboratoire. Mais, l’accession avec le moins de galles et de pontes a été une accession de L. virosa sensible à M. arenaria en laboratoire. Ainsi, des géniteurs intéressants pour la sélection de variétés de laitue résistantes aux nématodes ont été identifiés.

Dans un contexte règlementaire en pleine évolution (diminution du nombre de spécialités phytosanitaires disponibles), la maitrise du puceron Aphis gossypii dans les cultures de melon et de Thrips tabaci dans les cultures de poireau à l’aide de solutions phytosanitaires est de plus en plus difficile, et la recherche de méthodes de lutte alternatives et/ou complémentaires est nécessaire. Dans cette optique, des stratégies de protection basée sur l’utilisation de plantes de service (plantesressources, plantes-banque, plantes répulsives, plantes-écran et plantes-piège) ou bien sur l’utilisation de produits alternatifs (kaolin) ont été mises au point et évaluées dans le cadre du projet Casdar AGATH, porté par le CTIFL de 2013 à 2015 et labellisé par le GIS PICleg. Les résultats obtenus montrent que la mise en place de plantes-ressources et de plantes-banque autour des parcelles pourrait être efficace pour gérer A. gossypii en cultures de melon mais pas pour gérer T. tabaci en cultures de poireau, tandis que le phénomène inverse est observé pour ce qui concerne l’utilisation de plantes-répulsives et de kaolin. Enfin, certaines stratégies telles que l’utilisation de plantes-écran et/ou de plantes-piège n’ont pas montré d’intérêt dans le contexte expérimental des travaux menés., In a constant changing context (reduction in the number of pesticides available) the control of Aphis gossypii populations in melon crops and of Thrips tabaci populations in leek crops using pesticides is increasingly difficult. Then, the search for alternative and/or complementary solutions is required. With this in mind, new strategies of protection based on the use of service plants (resource-plants, bankerplants, repellent-plants, screen and/or trap plants) or on the use of natural products such as kaolin have been developed and evaluated in the framework of the AGATH project, managed by the French Institute for Fruits and Vegetables (CTIFL) from 2013 to 2015, supported by the French Ministry of Agriculture and Food, and labelled by the PICleg consortium. The results showed that the setting up of resourceplants and/or banker-plants all around the fields could be effective in controlling A. gossypii in melon crops but not in controlling T. tabaci in leek crops, while it is the opposite as far as the use of repellentplants or kaolin are concerned. Finally, some strategies such as the use of screen and/or trap plants did not show any interest in the experimental context of the work carried out.

National audience

Damage caused by pests and diseases on vegetables crops can lead to high economic losses. This is why with current changes to control strategies and a reduction in the use of plant protection products in Europe, knowledge on pests and diseases (host plants, geographic distribution, potential damage level...) has become as an unavoidable topic of work on air- or soil-borne pests and diseases, within the ‘GIS PIClég’ (Scientific Interest Grouping for Integrated Production of Vegetable Crops). In 2014 and 2015, a survey of all the pests anddiseases known in France was carried out, using expert ratings, which were then characterized. In this way, a list of key issues for which further research should be considered was established.; Les légumes sont des cultures pour lesquelles les dégâts engendrés par des bioagresseurs peuvent occasionner d’importantes pertes. C’est pourquoi, dans un contexte européen de modification des stratégies de protection et de réduction de l’utilisation des solutions phytopharmaceutiques, la connaissance des organismes nuisibles (plantes hôtes, répartition géographique, niveau de nuisibilité potentielle…) est apparue, au sein du GIS PIClég, comme un sujet de travail incontournable concernant les bioagresseurs aériens et telluriques. En 2014 et 2015, un recensement et une caractérisation de l’ensemble des bioagresseurs connus en France ont été entrepris, via une notation par des experts. Ainsi, une liste de problèmes clés pour lesquelles des efforts de recherche supplémentaires devront être envisagés.

National audience; Grâce au suivi de dispositifs sur six sites, l’objectif de Gedubat, « Innovations techniques et variétales pour une gestion durable des bioagresseurs telluriques dans les systèmes maraîchers sous abri », est de valider l’intérêt agronomique, socio-économique et environnemental de l’utilisation de pratiques améliorantes pour lutter contre les bioagresseurs du sol. Pour répondre à ces objectifs, différents mécanismes ont été identifiés : agir sur la physiologie de la plante, freiner le développement de l’inoculum tellurique et améliorer l’activité biologique du sol. Des stratégies agronomiques ont alors été élaborées dans différents systèmes de culture testés dans le réseau de parcelles, et déclinées à l’aide de règles de décision basées sur l’observation de l’état sanitaire des cultures.

National audience

National audience

National audience; In 2008, a nex invasive pest on tomato crop was accidentally introduced in France : the South American tomato leafminer Tuta absoluta. Phytophagus larvae are responsible for damage with a reduction in photosynthesis and fruit damage, causing yield loss. Despite the existence of some treatments against the pest that have low toxicity for beneficials, this new pest was real risk to crops in Integrated Biological Protection and Organic Agriculture on tomato. In this context was developped the CASDAR Project "TutaPi" (2011-2014), funded by the French Ministry of Agriculture. After three years of research, the results are positive, both in terms of the development and the effectiveness of strategies, and the importance of the role of beneficials. Collaboration and complementarity of the partners of this projetc, from research, experimentation and development has improved the knowledge of the pest. It validated and provided effective strategies for producers to control T.absoluta that are adapted to different crop conditions. A combination of methods and beneficial insects, either commercially available or naturally occurring, are at the heart of the strategy. The release of the predatory mirid bug Macrolophus pygmaeus had good control efficiency on T.absoluta and results were improved by simultaneus releases of Trichogramma achaeae. Since the new French legislation on the introduction of non native macro-organisms, it was of interest to work on endemic parasitoids, with lees risk to the environment and better adapted to our environmental conditions. The aim was also to find a more efficient and less expensive oophagous parasitoid (easier to mass rearing and storable) than T.achaeae

International audience

International audience; Background: Resistant cultivars are key elements for pathogen control and pesticide reduction, but their repeated use may lead to the emergence of virulent pathogen populations, able to overcome the resistance. Increased research efforts, mainly based on theoretical studies, explore spatio-temporal deployment strategies of resistance genes in order to maximize their durability. We evaluated experimentally three of these strategies to control root-knot nematodes: cultivar mixtures, alternating and pyramiding resistance genes, under controlled and field conditions over a 3-years period, assessing the efficiency and the durability of resistance in a protected crop rotation system with pepper as summer crop and lettuce as winter crop. Results: The choice of the resistance gene and the genetic background in which it is introgressed, affected the frequency of resistance breakdown. The pyramiding of two different resistance genes in one genotype suppressed the emergence of virulent isolates. Alternating different resistance genes in rotation was also efficient to decrease virulent populations in fields due to the specificity of the virulence and the trapping effect of resistant plants. Mixing resistant cultivars together appeared as a less efficient strategy to control nematodes. Conclusions: This work provides experimental evidence that, in a cropping system with seasonal sequences of vegetable species, pyramiding or alternating resistance genes benefit yields in the long-term by increasing the durability of resistant cultivars and improving the long-term control of a soil-borne pest. To our knowledge, this result is the first one obtained for a plant-nematode interaction, which helps demonstrate the general applicability of such strategies for breeding and sustainable management of resistant cultivars against pathogens.

Guide pratique pour la conception de systèmes de culture légumiers économes en produits phytopharmaceutiques

Travail réalisé avec le soutien financier de l'ONEMA; National audience

National audience; Dans le cadre de la protection contre Tuta absoluta (projet TutaPI), nous présentons les principaux résultats obtenus. L’objectif est d’améliorer les moyens de biocontrôle actuellement commercialisés, par la recherche d’un nouvel auxiliaire endémique, afin d’augmenter l’efficacité et diminuer les coûts de la protection

National audience

National audience

National audience

International audience; The current restrictions on the use of chemical nematicides have contributed to increase rootknot nematode problems in horticultural crops. ln this context, plant resistance appears as the most effective method of control, but the possible occurrence of virulent nematodes able to reproduce on R-plants may constitute a severe threat to this control strategy. ln Capsicum annuum, resistance to RKN is controlled by several dominant genes - the N and Me genes. To implement a rational management of the R-lines increasing the durability of the R-genes, we tested several R-gene deployment strategies. Experiments were conducted in climate-controlled roorns, in greenhouses, and under 3-years-field agronomie conditions to compare i) the succession of the same R-genes every year, when introgressed in a partially resistant vs. a susceptible genetic background, ii) the alternance, ii) the mixed cultivation and iv) the pyramiding of two R-genes with different modes of action in a single genotype. At the plant level, we previously showed that the choice of the R-genes and the genetic backgrounds in which they are introgressed can lower the frequency of resistance breakdown, and that the pyramiding of two different R-genes in one genotype totally suppressed the emergence of virulent isolates. Here, at the field and rotation level, we confirmed these results and showed that i) alternating different R-genes in rotation is efficient to reduce the selection pressure of R-genes on the pathogens and allows to recycle broken R-genes, and ii) optimal cultivation practices of R-plants increase their "trap" effect and may decrease the amount of pathogens in the soil, below their damage threshold. These results are in good agreement with concepts recently developed from the analysis of other plant-pathogen interactions. The root-knot nematode model could thus contribute to generalize strategies for the breeding and management of R-cultivars strengthening and increasing the durability of qualitative resistances

National audience; The recent banning of the most active chemical nematicides raised root-knot nematodes (RKN) as the major problem of vegetable growing in the south-east of France, with over 40% of horticultural farms affected. Resistant (R) cultivars successfully limit nematode attacks of the crop itself and reduce nematode abundance in soil in the short term. But their use in commercial fields faces two major constraints: (1) the limited number of cultivated species with RKN R-genes available (tomate. pepper), which would lead to major changes in crop rotations with socio-economic constraints; (2) the emergence of virulent root-knot nematode populations, able to overcome the resistance conferred by some of the R-genes. Recent research showed that the durability of the resistance per se was possibly increased with an optimal choice of the R-gene or allele combination, and of the genetic background in which the major R-genes where introgressed. However, the requirement for agronomic performance, does not always allow the breeder to fully use the genetic diversity available in R-genes and genetic backgrounds. ln such cases, spatio-temporal deployment strategies of resistant cultivars in the rotation were proposed and provided some success. But combination of genetic resistance with cultivation practices including multicrop rotations, intercultural management and/or prophylactic treatments was poorly tested for its ability to provide complementary selection pressures on the pathogen populations and to increase the durability of the protection. The project aims at identifying innovative strategies across the agrosystem, cornbining varietal resistance in crop rotations with agronomic practices, for a sustainable control of RKN that infect vegetable crops in protected crop systems. This pilot and demonstrative project involves analytical and systemic aspects: il the validation of previous results on the durability of RKN genetic resistance in tomato and pepper by long-term experiments in research stations and in farms, ii/ the impact of agronomic practices on the parasitic pressure in the soil and its contribution in the increase of resistance durability, and iii/ the impact of such innovations on the yield and the economie viability for protected crop systems in a Mediterranean climate. The added value here is to combine together currently dispersed approaches based on synergistic and long-term effects, towards a satisfying level of nematode control over pluri-annual crop sequences. The diversity of partners (research, experimental stations, technical institutes) and associated forces (growers' development structures, 'chambres d'agriculture') brings ail the complementary expertise needed for answering specifie short-term questions as weil as generic mid-long term expectations. 'GEDUNEM' has been launched in the framework of the INRA metaprogramme SMaCH (Sustainable Management of Crop Health).

International audience

La recrudescence de problèmes de sol, combinée à la diminution des moyens de contrôles chimiques, oblige les producteurs à intégrer des pratiques alternatives dans leurs systèmes de culture. Il peut s'agir de l'utilisation de la solarisation ou d'engrais verts, utilisés seuls ou en biodésinfection.

National audience

National audience; Market-gardening cropping systems in protected cultivation are very sensitive to soil-borne pests and diseases. Their productivity used to rely on pesticides, but alternative systems have now to be found for environmental, societal and health reasons. Many cultural techniques are known to provide some control of soilborne diseases, but are only partially efficient. The aim of the project is to design alternative systems with professionals, by improving the efficiency of the present techniques and/or imagining more innovative systems. The research project takes place in two steps. The first one consists in building a tool to assess the resistance or resilience of a given cropping system to soil-borne pests; the second one consists in using the tool with professionals in order to build alternative cropping and farming systems in cooperation. The model built for evaluation is a qualitative multicriteria tool. As scientific knowledge is not available for each technique or combination of techniques, empirical knowledge collected from growers and technical advisers is used to fill the gaps. The model is already built for root-knot nematodes and under construction for the other fungi. The second step will consist in using the tool with technical advisers and growers to redesign cropping systems and select the promising ones that should be put into trial in R&D stations. Co-building farming systems with stakeholders appears as an absolute necessity, to imagine solutions both efficient and acceptable for growers. The presentation will enable to discuss how combining expert and scientific knowledge may not only fill the knowledge gap, but also enable to build innovative solutions thanks to the diversity of experts' standpoints

International audience; Market-gardening cropping systems in protected cultivation are very sensitive to soil-borne pests and diseases. Their productivity used to rely on pesticides, but alternative systems have now to be found for environmental, societal and health reasons. Many cultural techniques are known to provide some control of soilborne diseases, but are only partially efficient. The aim of the project is to design alternative systems with professionals, by improving the efficiency of the present techniques and/or imagining more innovative systems. The research project takes place in two steps. The first one consists in building a tool to assess the resistance or resilience of a given cropping system to soil-borne pests; the second one consists in using the tool with professionals in order to build alternative cropping and farming systems in cooperation. The model built for evaluation is a qualitative multicriteria tool. As scientific knowledge is not available for each technique or combination of techniques, empirical knowledge collected from growers and technical advisers is used to fill the gaps. The model is already built for root-knot nematodes and under construction for the other fungi. The second step will consist in using the tool with technical advisers and growers to redesign cropping systems and select the promising ones that should be put into trial in R&D stations. Co-building farming systems with stakeholders appears as an absolute necessity, to imagine solutions both efficient and acceptable for growers. The presentation will enable to discuss how combining expert and scientific knowledge may not only fill the knowledge gap, but also enable to build innovative solutions thanks to the diversity of experts' standpoints.

Rencontres organisées par le pôle de compétitivité Qualiméditerranée de Montpellier Format du poster : 180X120cm; National audience

Etude financée par le Ministère de l'Agriculture et de la Pêche, et par le Ministère de l'Ecologie, de l'Energie, du Développement durable et de l'Aménagement du Territoire

National audience

Maîtres de stage : H. Lecoq, C. Desbiez, C. Taussig *INRA Centre d'Avignon, Documentation, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9 Diffusion du document : INRA Centre d'Avignon, Documentation, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9 Diplôme : MST

National audience

* INRA, Unité de Pathologie Végétale, Domaine St Maurice, 84143 Montfavet (FRA) Diffusion du document : INRA, Unité de Pathologie Végétale, Domaine St Maurice, 84143 Montfavet (FRA)

International audience; The current restrictions on the use of chemical nematicides have contributed to increased root-knot nematodes (Meloidogyne spp.) problems in horticultural crops. In this context, plant resistance (R) appears as the most effective method of control, but the restricted number of cultivated vegetable species with root-knot nematode R-genes available (tomato, pepper), and the possible occurrence of virulent nematodes able to reproduce on R-plants may constitute a severe threat to this control strategy. To increase the sustainability of the protection, a scientific challenge exists in building cropping strategies based on the combination of genetic resistance with cultivation practices. Our projects aimed at assessing such innovative strategies in a multi-site device in research stations and commercial farms. First, we looked at three components of crop protection, i.e., R-efficiency, R-durability, and sustainability of rotating cultivation. Overall, a constant hierarchy of management strategies was observed, with Pyramyding > Alternating > Mixture of R-genes > Sequential use of a single R-gene introgressed in a susceptible background. We are currently analysing (1) the impact of agronomic practices on the parasite pressure in the soil and on ecological diversity including other nematode species, (2) the linkage between reduction of Meloidogyne populations in the soil and increase of R-genes durability, and (3) the sustainability assessment of such varietal and technical innovations. Multidisciplinary approaches were combined to foster synergistic and long-term goals. The diversity of partners and associated forces brought all the complementary expertise needed for answering specific short-term questions as well as generic mid- to long-term expectations.