Search results for "EED"
showing 10 items of 5952 documents
Simulation study of the effects of intensified crop management in genetically manipulated maize on arable weed flora and associated fauna
2014
International audience; Cultivation of GM crops with herbicide tolerance is mostly associated with changes in crop and weed management, like simplified rotations, simplified tillage and change from selective herbicides to the broadband glyphosate. All of these management practices decrease weed densities in crops and change their composition. Although weeds cause yield loss and harvest problems, they are an important part of arable biodiversity and offer food and habitat for different groups of animals. A simulation study was conducted to analyse indirect effects of intensified cropping in GM maize on biodiversity. The dynamic crop: weed model FlorSys was used to simulate weed densities and…
Adapting cropping system to delay herbicide resistance. A simulation study
2014
Weeds have evolved resistance to numerous herbicides, and their management becomes increasingly expensive and difficult. Here we (1) adapted the existing weed dynamics simulation model AlomSys to account for target-site resistance to acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides in Alopecurus myosuroides by integrating wild and mutant target-site resistant (TSR) genotypes, mutations, fitness costs and seed immigration, and (2) ran simulations testing different crop management practices for their ability to delay resistance evolution and/or control of TSR plants. Simulations of an oilseed rape/winter wheat/winter barley rotation showed that TSR plants exceeded 1 plant/m² appro…
Assessing the effect of changes of agricultural practices accompanying herbicide-tolerant crops on agricultural biodiversity. A simulation study with…
2014
International audience
Ex Ante evaluation of gene flow in oilseed rape with cropping system models
2013
Chapitre 4; Oilseed rape (OSR) genes can escape fields in space via pollen and seeds, and in time via volunteers resulting from seeds lost before or during oilseed rape harvest. When varieties co-exist, e.g. genetically-modified (GM) and non-GM varieties, this spatio-temporal gene flow can lead to the adventitious presence of GM seeds in non-GM harvests and thus cause financial losses for farmers and cooperatives. Gene flow depends on crop locations, succession, and management, as well as the location and management of semi-natural areas such as roadverges. The objective of this investigation was to present a simulation methodology using the spatially-explicit cropping system model GENESYS …
Proposing a set of simulation-based indicators to assess harmfulness and biodiversity resulting from weeds in agroecosystems
2013
International audience; Weeds are both a harmful pest and an important trophic resource for many biotic components. Moreover, herbicide use must be reduced to limit its impact on environment and human health. Consequently, new cropping systems are needed that both maximise weed-related biodiversity and minimise weed harmfulness. Weed dynamics models are increasingly used to design innovative cropping systems but they only consider weed densities and/or crop yield loss. Thus, the objective of the present study was to develop a set of indicators to assess weed-related harmfulness and biodiversity and to connect them to the FLORSYS model. The FLORSYS model is to date the only multispecific wee…
Identification of potential mycoherbicides using a metabarcoding approach
2018
National audience
Et si une impasse de désherbage en agriculture de conservation des sols vous poussait à retravailler le sol ? Quelle intervention choisiriez-vous ?
2019
National audience; En Agriculture de Conservation des Sols (ACS), la perturbation minimale du sol est l’un des trois prin-cipes. Si l’impasse se fait sentir mieux vaut repenser le système que de laisser le mur se rapprocher à grands pas. Trois types de gestion d’interculture (Labour, travail superficiel (TCS) et semis direct avec glyphosate (SD)) ont été comparés sur des parcelles conduites sans labour depuis 17 ans dont les 7 dernières années en ACS sur le domaine de l’INRA de Dijon avant implantation d’un blé, sur un dispo-sitif en bandes répétées sur quatre parcelles. Des relevés de flore adventice, rendement et compo-sante de rendement ont été faite. Les densités moyennes sont faibles p…
Peut-on réduire les herbicides sans perdre de rendement ?
2019
Afin de concevoir des systèmes agricoles durables et économes en herbicides, il est indispensable de comprendre les relations entre usage d'herbicides, niveau d’infestation par les adventices et pertes de rendement. Comme les agriculteurs raisonnent l'utilisation des herbicides en fonction de la flore et de leurs autres pratiques (ex. travail du sol, date de semis, rotation), il est difficile d'évaluer ces relations directement en parcelles agricoles, tant les possibilités sont nombreuses. Notre étude a donc choisi de traiter la question via l’utilisation d’un modèle de simulation. Nous avons collecté et simulé 272 systèmes de culture d'agriculteurs de sept régions avec la flore adventice t…
Estimation de l’indice foliaire et de la biomasse du blé et des adventices par imagerie visible et machine learning : vers un nouvel indicateur non d…
2019
National audience; Cette étude propose d’estimer précocement par imagerie deux variables clés dans la gestion des cultures et dans la compétition culture-adventices : l’indice foliaire (LAI) et la biomasse aérienne sèche (BM). Une expérimentation a été conduite au champ pendant la phase végétative d’une culture de blé. Pour chaque peuplement (culture de blé, adventices), les taux de couverture du sol par la végétation (TCc, TCw) ont été déduits du traitement d’image basé sur une technique de machine learning. LAI et BM ont été mesurés de façon destructive. Puis, une calibration a été réalisée entre TC et LAI d’une part et entre TC et BM d’autre part. Ce travail pourrait, à terme, faciliter …
Modélisation des effets des systèmes de culture sur la dynamique de la plante parasite orobanche rameuse en interaction avec les adventices
2019
Reducing pesticide use is a major challenge in agriculture and involves developing more sustainable methods that rely on non-chemical cropping techniques and biological regulations according to agroecological principles. Branched broomrape (Phelipanche ramosa (L.) Pomel) is a root parasitic plant which infects crops and causes dramatic yield losses worldwide. Managing broomrape is complex because it requires combining several cropping techniques whithin a global weed management strategy because broomrape is also able to infect non-parasitic weeds. The aim of this thesis was to stynthetize knowledge on branched broomrape dynamics in agroecosystems and to aggregate it within a mechanistic mod…