Дисертації з теми "Bioagressors"
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Eichenlaub, Lisa. "Anticiper, comprendre et analyser les pathologies complexes et émergentes des chênes." Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0148.
Повний текст джерелаEuropean oaks (Quercus robur, pedunculate oak and Q. petraea, sessile oak) are two emblematic forest species with important ecological, economical and cultural roles. These species are essential in many ecosystems and represent respectively 11 and 12% of the volume of standing wood of deciduous trees in France. However, they are subject to biotic and abiotic disturbances, which have increased in frequency and intensity due to global changes. Declines, which are multifactorial syndromes, and diseases caused by exotic or native pathogens, have strongly affected oaks since the beginning of the 20th century. The nature of these declines, as well as the interactions between biotic and abiotic factors causing them, are not fully understood. This thesis proposes to define part of their etiology through a study of the cortical and root pathobiomes. Finally, it stresses the importance of territorial surveillance as a way to prevent the introduction of exotic pathogens, especially the threat represented by quarantine organisms. Acute Oak Decline (AOD) is currently affecting oak populations in the United-Kingdom. Mediated by abiotic factors (temperature and precipitation), AOD would be triggered by insects (mainly Agrilus biguttatus) and a complex of bacterial species. This disease perfectly illustrates the pathobiome paradigm, as the complex host-pathobiome-insect interactions are essential to its development. In order to clarify the prevalence of symptoms associated with AOD in France and the role played by bacteria in the observed declines, a study of the etiology of cortical necroses associated or not with attacks of A. biguttatus on declining oaks has been observed. The first report on the presence of bacteria Brenneria goodwinii, Gibbsiella quercinecans and Rahnella victoriana in necroses has been made on Q. robur and Q. petraea in France. However, these bacteria have been isolated less frequently in the lesions than the fungi Fusarium quercinum, F. falsibabinda, Neonectria sp., N. punicea. Moreover, their pathogenicity was confirmed by the inoculations of young oak plants. This confirms the importance of the pathobiome in the symptoms associated with AOD and suggests a significant role of fungal pathogens, which was previously underestimated. The relationships between soil microbiota and chronic oak decline were analyzed in the Chantilly Forest (Oise, France) and with a comparison approach by pair of declining and non-declining oaks, an analysis of the fungal and oomycetes diversities by metabarcoding was performed. The study revealed that the compositions mainly depend on the types of soil and the health status of the trees according to the compartment sampled (bulk soil, rhizosphere or roots). 4 Finally, to help the diagnosis and the identification of phytosanitary problems on Quercus spp. in France, an interactive tool called NESTOR (phytosaNitary survEillance and diagnoSTics of Oaks in FRance), has been developed. Inventorying the main bioaggressors and abiotic problems on oaks with this tool is intended to encourage passive surveillance of the territory by the general public and professionals and also to support the active surveillance of the territory led by the Forest Health Department of the French Ministry of Agriculture and Food in France. In 2022-2023, intensified surveillance of oak wilt disease, caused by the vascular fungus Bretziella fagacearum, was carried out by collecting samples from symptomatic trees. The isolations and diagnoses conducted during this thesis confirmed that the fungus is still absent from the territory, but that it remains important to stay vigilant about its possible introduction in France
Gidoin, Cynthia. "Relations entre structure du peuplement végétal et bioagresseurs dans les agroforêts à cacaoyers. Application à trois bioagresseurs du cacaoyer : la moniliose au Costa Rica, la pourriture brune et les mirides au Cameroun." Phd thesis, Ecole nationale superieure agronomique de montpellier - AGRO M, 2013. http://tel.archives-ouvertes.fr/tel-01015863.
Повний текст джерелаPoeydebat, Charlotte. "Régulations écologiques d'un complexe de bioagresseurs du bananier dans un gradient de complexité végétale des agroécosystèmes." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT165.
Повний текст джерелаAgriculture intensification and biological simplification of agroecosystems lead to the loss of ecosystem functions while chemical control of pests is not sustainable. Agroecosystem plant diversification is increasingly recognized as a way to restore positive interactions among plants benefiting crops, such as pest regulations. But diversification that causes resource sharing must not be done at yields’ expense. If vegetation complexity is the basis for pest regulation services, what should be the level of the regulations to compensate for yield losses due to competition for resources? What should be the composition and structure of the plant community to synergistically optimize multiple pest regulations and yields? First, I quantified by theoretical modeling the minimal levels of pest regulation required to compensate for yield losses due to competition in various association and resource scenarios. I then conducted a field study to study the ecological regulations of three important pests of bananas along a vegetation complexity gradient. Finally, I quantified the amount of yield losses attributable to pests and resources. I discuss the interactions between pest damage and resource competition at plant scale, the mechanisms implied in ecological regulations of the three banana pests and the management of the plant community at field scale for the synergic regulation of multiple pests and yield optimization
Collange, Béatrice. "Vers une Gestion Agronomique des Bioagresseurs Telluriques en Maraîchage sous Abri : Evaluation de Systèmes de Culture." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22032.
Повний текст джерелаIn the current context of the reduction of pesticide use, soilborne pests and diseases, and especially the fungi Sclerotinia and the root-knot nematodes Meloidogyne, become more and more worrying in vegetable production under shelter in Southern France. Alternative techniques exist, but their partial and varying efficiencies require the search for new strategies of management of these pests and diseases fit for producers.Therefore, the aim of this study is to determine the benefit of combinations of two techniques, soil solarisation and green manure (Sorghum sudanense). It is also to determine the influences of crop successions and frequences of these techniques on their individual efficiencies.To this effect, a setup of producers' plots has been designed. The spatiotemporal evolution of incidences and severities of Sclerotinia and Meloidogyne in several cropping systems has been observed on this setup.The presence of a melon crop has a major influence on the efficiency of the alternative techniques. Opposite effects for the two considered pests and diseases appeared. Crops successions with melon are most favourable to highest infestations of Meloidogyne whereas, Sclerotinia infections are reduced. For this pathogen, a solarisation every year or every two years ensures the most effective control. On the contrary, in the case of Meloidogyne, the melon crop is very sensitive to this pest, a characteristic that masks the positive effects of alternative techniques
Pensec, Flora. "Les triterpénoïdes chez la vigne : quantifications, voies de biosynthèse et intérêt pour la lutte contre des bioagresseurs." Thesis, Mulhouse, 2013. http://www.theses.fr/2013MULH8854/document.
Повний текст джерелаVitis vinifera is susceptible to many pathogens. These past few years, treatment policies led to the withdrawal of many pesticides. Renee, no chemical treatments are available to treat some grapevine diseases such as the grapevine trunk diseases caused by fungi complexes and the grapevine fanleaf degeneration, a viral disease transmitted from grapevine to grapevine by vector nematodes. Grapevine is known for the production of secondary metabolites as a response to pathogen infections. In this work, we focused on phytoanticipins such as triterpenoids, that are found as preformed compounds and that confer a basal resistance level to plants. First, a chemical analysis was made on the triterpenoid composition of some grapevine cultivars and organs. This study revealed that the triterpenoid composition is specific to the V. vinifera cultivar and the organ. In a genomic approach, 9 candidate genes involved in the triterpene biosynthesis were identified and their expression was studied in different organs, varieties and biotic or abiotic stress conditions. This explorative study shows correlations between gene expression and differential triterpene production at the leaf surface of the different varieties. In the last part of this study, the use of glycosylated triterpenes, also called saponins, as a substitution solution to withdrawed treattnents against major grapevine diseases was tested. Therefore, the efficiency of saponins extracted from gypsophila and quillaja was tested against fungi associated to grapevine trunk diseases and some nematodes vector of the grapevine fanleaf degeneration. These tests evidenced that the fungi were able to avoid saponins toxicity, whereas such treatment was efficient to kill nematodes. In order to evaluate the effect of the treatment on the environment, the efficient doses were tested and bad no significant impact on some bioindicators
Gidoin, Cynthia. "Relations entre structures de peuplement végétal et bioagresseurs de la culture principale dans les agroforêts tropicales. Application aux agroforêts à cacaoyers et à 3 bioagresseurs : la moniliose (Moniliophthora roreri) au Costa Rica, la pourriture brune (Phytophthora megakarya) et les mirides (Sahlbergellasingularis) au Cameroun." Thesis, Montpellier, SupAgro, 2013. http://www.theses.fr/2013NSAM0027/document.
Повний текст джерелаThe potential value of tropical agroforests as a model for ecological intensification of agriculture is a subject of increasing interest. Tropical agroforests are agroecosystems characterized by high plant diversity and a complex spatial structure of individuals. With their forest-like structures, agroforests are close to natural ecosystems. The complex structure of agroforests would seem to improve the provision of numerous ecosystem services.This work concerned natural pest and disease regulation services in complex agroecosystems. Our hypothesis was that complex agroforest structures (composition and spatial structure) influence the pest and disease attack intensity on the main crop. Indeed, an increase in plant diversity in agroecosystems is known to reduce specialized pest and disease attack intensity due to a decrease in resource abundance and density on a plot scale. Conversely, plant diversity could increase the generalist pest and disease attack intensity due to the potential introduction of alternative hosts. Moreover, diversity in plant spatial structure has an impact on microclimatic conditions and, thereby, on the pest and disease attack intensity. However, the relative importance of host composition effects on pest and disease intensity, due to resource dilution or amplification, and plant spatial structure effects, due to microclimatic alteration, is still unknown.Our objective was to quantify interactions between the composition and spatial structure characteristics of agroforests and the pest and disease attack intensity on a plot scale.This work was applied to cacao agroforests in Costa Rica and Cameroon. Indeed, cacao is one of the last crops still to be grown in traditional agroforests in the majority of producing countries. The study was conducted on two cacao diseases and one pest chosen for their contrasting spread and development characteristics: in Costa Rica, Frosty Pod Rot (FPR) intensity was studied in cacao agroforests in the Talamanca region; in Cameroon, Black Pod (BP) intensity and mirid density were studied in cacao agroforests in the Centre region.Firstly, we established shade tree spatial structure typologies for cacao agroforests in Costa Rica and Cameroon, in order to identify spatial structure diversity in the same region. A diversity of spatial structures was identified ranging from significant regularity to significant aggregation, depending on the shade tree stand and country studied.Secondly, we identified and classified the host composition, amount of sensitive tissue and the spatial structure characteristics of the associated plants, according to their explanatory power in explaining FPR intensity, BP intensity and mirid density in cacao agroforests. The spatial structure of the associated plants was a crucial characteristic of agroforests in explaining FPR and BP intensity and mirid density. Indeed, forest tree regularity decreased FPR intensity in Costa Rica and mirid density in Cameroon. The BP intensity was reduced by a decrease in the density of individuals belonging to strata lower than or equal to the cacao tree stratum. Lastly, the amount of sensitive tissue rather than the host composition variables explained the increase in FPR intensity in Costa Rica and the mirid density in Cameroon. Our results are discussed in line with several mechanisms that explain plant diversity and pest and disease relationships.Our work provides a precise description of complex tropical agroecosystem structures. We quantified the relationship between observed plant structures and the pest and disease regulation ecosystem service. In the context of agroecology, this work opens up prospects for identifying and understanding ecological mechanisms involved in natural pest and disease regulation in cacao agroforests on a plot scale
Bellee, Anthony. "Approches multidisciplinaires sur le mode d’action, l’efficacité et l’élaboration de stratégies d’utilisation d’actifs biologiques contre divers bioagresseurs de Vitis vinifera." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0201.
Повний текст джерелаGrapevine is a perennial crop sensitive to many fungal pathogens that require numerous pesticide treatments. However, its uses lead to environmental, human health and fungicide resistance problems. Developing sustainable pest management strategies while keeping a good wine quality is of major importance. In this sense, the use of bio-pesticides products seems to be a promising approach to combine sustainable and intensive agriculture.Two generalist bio-pesticides of great potential have been preliminary identified, forits actions on major fungal diseases of grapevine. The first one is a natural plant extract, with no direct fungicide action but able to systemically stimulate plant defenses. The second one is a microorganism showing strong antagonist fungicide actions, and important ability to stimulate plant defenses. First, the studies conducted in controlled conditions have demonstrated the effectiveness of both products in the suppression of various isolates of Erysiphe necator, Plasmopara viticola, Botrytis cinerea and Botryosphaeriaceae. In parallel,the good efficiencies of these products have been confirmed during vineyard assays. This was especially well demonstrated for the natural extract. As a whole, these studies confirm thepotential of these two products as promising bio-pesticides, of which the strategy of application have been further defined
Vedy-Zecchini, Marie-Anne. "Analyse et modélisation des effets du système de culture et de la situation de production sur les principaux bioagresseurs du tournesol." Thesis, Toulouse, INPT, 2020. http://www.theses.fr/2020INPT0004.
Повний текст джерелаSunflower has many agroecological benefits (resistance to abiotic stresses, low Treatment Frequency Index, maintenance of pollinator biodiversity), but its surface area and yield have stagnated for nearly 30 years. These stagnations are due in particular to a collection of pests. In a context of pesticide reduction, non-chemical prophylactic (or preventive) methods must be promoted against pests. However, it is difficult to predict the effects of one or more cropping practice(s) on pest development. Models are essential tools to reach this objective. Three pests were considered in this thesis: two phytopathogenic fungi, phomopsis stem canker (Diaporthe helianthi) and phoma (Leptosphaeria lindquistii), because of the available knowledge and datasets; and a plant parasitizing exclusively sunflower, broomrape (Orobanche cumana) because of the damages it generates. Indeed, it has recently appeared in France and is rapidly expanding. These three pests can generate significant crop losses. The conducted work addressed three questions: i) How to manage primary inoculum production of these pests? ii) How to value the available knowledge on the effects of cropping practices and production situations on the biological cycles of these pests? iii) How to improve the modeling methods used? Syntheses of scientific and technical literature have been conducted. The expertise of plant pathologists and agronomists has been elicited and formalized. Original algorithms have been developed in order to adapt two generic models to different pests. The generic SimMat dynamic model was used to address the first question. This model predicts the effects of rainfall and temperature on the sexual reproduction of ascomycete fungi. It has been adapted to phomopsis and phoma of sunflower. The second question was addressed using the IPSIM (Injury Profile SIMulator) approach, which allows the development of qualitative models predicting the effects of cropping practices and production situations on injuries caused by one or several pest(s). Two qualitative models were created for phomopsis stem canker and phoma and the model for phomopsis stem canker was evaluated. A preliminary model has been proposed for broomrape. Four of these models have been adapted using innovative methods to improve their predictive qualities. In particular, a method for hybridizing expert knowledge and the information contained in the datasets has been developed. The thesis therefore made it possible to develop a set of models contributing to the management of biotic stresses of sunflower, and generic methodological breakthroughs for modeling. Operational tools are now available to contribute to the implementation of agroecological protection strategies for sunflower
Muneret, Lucile. "Déploiement de l’agriculture biologique à l’échelle du paysage : impacts sur les communautés d’ennemis naturels et les services de régulation des bioagresseurs." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0031/document.
Повний текст джерелаIdentifying landscape context and farming systems that enhance natural pest control while maintaining biodiversity is crucial to design functional agricultural landscapes. Using a meta-analysis and an empiric study based on 42 vineyards in Nouvelle Aquitaine (France), we investigated the effect of the deployment of organic farming at a landscape scale on 1) natural enemy communities, 2) natural pest control and 3) pest infestation levels. Here, we showed that the proportion of organic farming structured more natural enemy communities than the proportion of semi-natural habitats. On the opposite, pest and pathogen infestations were never influenced by the proportion of organic farming while they were negatively influenced by the proportion of semi-natural habitats. Furthermore, at a global scale and for every crop types, organic farming, per se, enhances natural pest control. In viticulture, it is less dependent of synthetic agrochemicals than conventional farming. Moreover, local factors such as the treatment frequency index, the field age and the crop productivity had important effects on natural enemy communities and natural pest control. Finally, we yielded knowledge on processes that impact natural enemy assembly and natural pest control in agrosystems. For vineyards-dominated landscapes, our work suggests some tracks for landscape planning that support biodiversity conservation and natural pest control
Royer, Mathilde. "Étude des relations entre croissance, concentrations en métabolites primaires et secondaires et disponibilité en ressources chez la tomate avec ou sans bioagresseurs." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0058/document.
Повний текст джерелаNowadays, limiting the use of pesticides is mandatory. A promising way for research deals with the environmental determinism of plant defence mechanisms, among others, production of secondary metabolites. The aim of my PhD work was to study the trade-off between growth and defence (primary vs. secondary metabolism) in healthy plant tissues or attacked by different pests, under different conditions of resources availabilities. We measured different growth parameters, C:N ratios of tissue, concentrations of main primary metabolites (simple carbohydrates, starch) and defence metabolites (chlorogenic acid, rutin, kaempferol-rutinoside and tomatine) on healthy or attacked tomato plant grown in hydroponic culture in greenhouse or phytotron. We observed that variations of total and resources C:N ratios were positively correlated to that of several defence compounds whatever their composition in carbon and nitrogen. Moreover, we showed that, during pests attack, concentrations of primary and secondary metabolites did not follow the same evolution, depending on their nature. Caffeoyl putrescine synthesis was strongly induced by P. syringae inoculation whereas chlorogenic acid concentration decreased. Inoculation of P. syringae induced a strong decrease of concentration of glucose and fructose whereas inoculation of P. corrugata enhanced their synthesis. We observed that a low N availability alters the development of P. syringae, P. corrugata and Tuta absoluta but promotes the development of B. cinerea. Our results showed that C:N ratio is a reliable indicator of the trade-off between growth and defence in the case of healthy plant. In attacked plant, the resources allocation between different metabolites varies with pests. And each pests reacts specifically to changes of N availability for the plant. Control of culture conditions appears to be a relevant agronomic tool to monitor the control of pests even if it is difficult to apply general rules to the interaction plant/environment/pests
Fernandez-Conradi, Pilar. "Diversité des arbres et résistance des forêts aux invasions biologiques : application au chataignier et son complexe de bioagresseurs exotiques, chancre (Cryphonectria parasitica) et cynips (Dryocosmus Kuriphilus)." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0940/document.
Повний текст джерелаPlants are the playground of a large diversity of biotic interactions between related and unrelated organisms exploiting them as common resources. The aim of this thesis was to understand how plant-insect interactions vary with fungal infection of their host plant and plant diversity. I first performed a meta-analysis to provide a theoretical background for plant-mediated effects of fungal infection on herbivorous insects. Overall, I found a negative plant-mediated effect of fungi on both insect preference and performance. However, this effect varied according to fungus lifestyle, insect feeding guild and spatial location of the interactions (local vs distant). Then I experimentally tested plant-fungus-insect tripartite interactions in the particular case of exotic bio-aggressors of the European chestnut (Castanea sativa): the Asian chestnut Gall Wasp (ACGW, Dryocosmus kuriphilus), and the fungal pathogen Cryphonectria parasitica, the causal agent of chestnut blight. I performed an observational study, in natural chestnut forest stands in Italy, where I tested how ACGW infestation rates vary with the tree species composition. I also investigated the mechanisms underlying plant diversity effects on the invasive pest, with a particular focus on its natural enemies such as insect parasitoids and endophytic fungi. ACGW infestation rates was lower in oak and ash chestnut mixtures compared to monocultures or pine-chestnut mixtures. Plot composition also influenced ACGW parasitoid community composition but not their abundances, diversity or richness. Endophytic communities of galls, described by using next generation sequencing methods, did not vary with plot composition. However, they strongly differed from surrounding leaf tissues. We thus provided evidence that plant diversity and fungal pathogens are key drivers of plant-insect interactions. Understanding how plants interact with associated insects and fungi, and mechanisms underlying plant diversity effect on these interactions, will improve our knowledge on diversity-ecosystem functioning relationships and will have practical applications for the management of native and exotic forest pests
Robin, Marie-Hélène. "Analyse et modélisation des effets des pratiques culturales et de la situation de production sur les dégâts causés par les bioagresseurs des cultures. Application au blé d’hiver." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2014INPT0067/document.
Повний текст джерелаIntegrated pest management (IPM) appears as a sustainable strategy to protect plants against pest while answering the economical, ecological, and toxicological expectations that agriculture must face. The effects of cultural practices on pest dynamics have to be thoroughly analyzed in order to reduce the reliance of cropping systems on pesticides. A model, named IPSIM ((Injury Profile SIMulator), currently under development in this thesis, aims at simulating the effects of cropping practices, as well as soil, climate and field environment on the injuries caused by multiple pests of a given crop. This model is based on a hierarchical and aggregative approach. This study describes the conceptual basis of the modeling and its applications in order to develop IPSIM-Wheat, a model simulating injury profiles on wheat. Thus, several models have been designed to predict six diseases, one insect pest and weeds. This study thus contributes to the development of IPSIM-Wheat which will help design innovative sustainable wheat-based cropping system
Dufour, Marie-Cécile. "Etude de l'efficacité des défenses de différents génotypes de Vitis induites par élicitation face à la diversité génétique de bioagresseurs (Plasmopara viticola et Erysiphe necator) : du gène au champ." Thesis, Bordeaux 2, 2011. http://www.theses.fr/2011BOR21847/document.
Повний текст джерелаPowdery (Erysiphe necator) and downy mildew (Plasmopara viticola) are very important grapevine diseases (Vitis vinifera). These two biotrophic pathogens, which are native to the United States, infect green vine tissues and cause significant economic loss as well as environmental damage through the repetitive applications of fungicides. To reduce their environmental impact efforts should be made to develop strategies to protect innovative alternative or complementary to reduce pesticide inputs.In this study, the efficacy and the role of Benzothiadiazole (BTH), a salicylic acid analogue, and two phosphonate derivatives strengthen plant defence mechanisms against various isolates of downy and powdery mildews (Plasmopara viticola and Erysiphe necator). These compounds showed differences in their efficacy depending on the variability of mildews and highly dependent on plant genetics, environmental conditions and selection pressure. The plant defense stimulation could be an alternative or additional method to traditional pest management in the grapevine.Tools “BioMolChem” were developed to better assess the defence status of the plant defences in vitro and in natura. Transcript kinetics of selected defence-related genes and polyphenol contents profiles, during Vitis vinifera-biotrophic pathogen interaction, were characterized, and the impact of pathogen diversity was investigated in the absence or presence of elicitation. In vineyard, under strong pathogen pressures, it is thus possible to protect leaves and clusters, with SDP and assays of association or alternation with conventional fungicides show the potential interest of the use of these SDP in the vineyard.The grapevine defense mechanisms are complex, depending on the elicitor, leading to the coordinated accumulation of pathogenesis-related proteins (PR), the production of phytoalexins, and the reinforcement of plant cell walls.On the way, within the framework of an innovative and sustainable viticulture, the SDP was applied to hybrid genotypes (V. vinifera x M. rotundifolia). We reveal that according to the level of intrinsic resistance of the genotypes (more or less resistant to powdery and to downy mildew), it is possible to increase the level of the expressed resistance. The SDP could become allies of interest in the use of partially resistant grapevine varieties.The present findings provide insights into the potential use of transcripts and stilbenes as markers of the defense status of grapevine leaves with or without elicitation or infection, which should allow us to exploit and develop a better use of elicitors in alternative or complementary strategies in grapevine pest management
Boulestreau, Yann. "Une démarche de co-conception d’innovations du système de culture au système agri-alimentaire pour une gestion agroécologique des bioagresseurs telluriques en maraîchage provençal Analyzing barriers and levers for practice change: a new framework applied to vegetables’ soil pest management." Thesis, Avignon, 2021. http://www.theses.fr/2021AVIG0725.
Повний текст джерелаA rapid and far-reaching change towards farming practices that contribute to the protection of the environment and the human health is needed. In many cases, these alternative practices exist but are not implemented due to interconnected barriers at the plot, farm, territory, value chain and/or global level. In my thesis, I developed a methodology taking into account the determinants of the farming practice choices at the different levels to support the change in farming practices. I applied this methodology to a specific case study: the management of soil-borne pests and diseases, mainly root-knot nematodes, in sheltered vegetable farming systems in Provence (France). The impact of root-knot nematodes on vegetable crops is significant both in Provence (40% of farms affected) and worldwide. Their management is essentially based on the use of non-selective nematicides that are damaging for the human health and the environment.First, I carried out a sociotechnical analysis showing that most of the Provençal agri-food system was locked around the use of "radical soil disinfection" techniques, thus excluding the implementation of alternative agroecological techniques. This lock-in arose from interconnected barriers to the change in practices, involving a diversity of stakeholders at the Provençal level and beyond it: farmers, upstream and downstream of the sector (including consumers), R&D and public policy actors. Following this analysis, I studied existing coupled innovations that foster the implementation of agroecological crop protection in French vegetable systems. This “tracking of innovations” led us to identify 5 types of coupled innovations, and for each of them, the combinations of sociotechnical levers mobilized and the way they were implemented. Meanwhile, I developed a serious game enabling the effective sharing of the sociotechnical analysis results to the stakeholders of the studied problem. This serious game also enabled to facilitate stakeholders’ knowledge management and creativity and the collaboration between them, for initiating the design of innovative solutions tailored for the problem under study. Finally, I mobilized the previous works (analysis, tracking, serious game) in 4 co-design workshops conducted with the stakeholders. I created and implemented several methods in these workshops to design increasingly elaborate solutions that favor change in practices. As a result, we collectively designed 50 coupled innovations including 41 coupled innovations, thus opening up the space of possible solutions. We evaluated part of the complex coupled innovations.In the discussion, I point out the promising avenues of action and research to facilitate the implementation of agroecological practices for the management of soil-borne pests and diseases in Provençal sheltered vegetable farming systems. I discuss the possible evolution of the methodology I developed during this thesis, in order to improve its efficiency and complete the design process. I make proposals to specify the conditions of the implementation of the innovations designed, evaluate them and anchor them in the territorial agri-food system. Finally, I show that this work contributes to establishing theoretical and methodological bases to multi-level redesign of agricultural systems for accompanying changes in farming practices.Parts A "Problem" and C "Discussion" of my thesis are written in French. Part B consists of three articles and one chapter of the thesis written in English
Demestihas, Constance. "Analyse des conflits et synergies entre services écosystémiques multiples en vergers de pommiers." Thesis, Avignon, 2017. http://www.theses.fr/2017AVIG0690/document.
Повний текст джерелаThe concept of « ecosystem service », which has been used increasingly since the publication of the Millennium Ecosystem Assessment in 2005, has highlighted the importance of ecosystem’s non-marketed performances. In orchards, ensuring high productivity while preserving natural resources and human health has become a real challenge that could be analyzed with the concept of ecosystem service. Which ecosystem services are delivered in an apple orchard? How to analyze them? What are the relationships - conflicts or synergies – among multiple ecosystem services and how do cropping systems change multiple ecosystem service profiles? This PhD work aims at answering those questions with an innovative approach combining experimental measures, modeling and statistical analysis.Based on a literature review of ecosystem services in orchards, five services were selected: fruit production, nitrogen availability in soil, climate regulation based on the prevention of nitrogen denitrification and on carbon sequestration, maintenance and regulation of water cycle, including water quality, and pest control. We also considered the environmental disturbances caused by the use of pesticides. For each service, we identified the underlying ecosystem functions as well as the agricultural practices and soil and climate conditions affecting these functions. Services and functions were described by one or multiple indicators and quantified using models in the case of (i) nine existing cropping systems on two experimental sites in southeastern France differing in terms of soil and climate conditions, and (ii) 150 virtual cropping systems designed out of the combination of five major agricultural practice levers and their modalities, in identical soil and climate conditions. The two models used were STICS, a generic soil-crop simulation model under the influence of practices which required a parameterization and an evaluation on apple orchards based on experimental measures, and IPSIM, a generic modeling framework simulating the impacts of agricultural practices and local conditions on crop injuries caused by pests. IPSIM was parameterized on apple orchards, based on an important literature review and expert opinions. Model simulations were analyzed with simple statistics in the case of the nine existing cropping systems and with two-table multivariate analyses (principal component analysis with instrumental variables) for virtual cropping systems.Concerning the existing cropping systems, 14 important relationships were identified among ecosystem services, especially conflicts, like the one between nitrogen denitrification or leaching prevention and soil nitrogen availability on the short term, and synergies such as the one between soil humidity or carbon sequestration and nitrogen availability on the short term. These relationships are explained by the underlying ecosystem functions. Comparing service profiles among cropping systems highlighted the impacts of agricultural practices on some services. That way, on a same site, a high planting density increases fruit production and carbon sequestration. An exclusively organic fertilization decreases fruit production through nitrogen stress but also nitrogen leaching in drained water. Furthermore, service profiles are strongly influenced by the soil and climate conditions of each site. These results strengthen the need to explicitly consider the ‘agricultural practices x soil and climate conditions’ interdependence in order to analyze ecosystem services. The results obtained with the virtual cropping systems simulations confirmed those of the existing ones and gave precision on the impacts of fertilization, irrigation and pest control for codling moth, rosy apple aphid and apple scab on ecosystem functions and services