Search results for "adventice"
showing 10 items of 137 documents
Dispositifs d’imagerie multi-spectrale pour la détection et le contrôle des adventices
2007
National audience; pas de résumé
Diversité fonctionnelle au sein des communautés de plantes adventices : effet de la rotation et du type de culture
2012
During this internship I investigated the effects of habitats i.e. field margin or the core of the field, and of crop sequences weed taxonomic and functional diversity in arable fields. We selected 75 fields from a database of flora surveys that have been conducted since 2005 in the area of Fénay. In the 75 fieds, the flora was sampled four consecutive years. The indices of Shannon-Weaver, Simpson and Pielou and species richness were selected for taxonomic study, while Rao's quadratic entropy and the community weighted mean (CWM) of the traits in the community were used for the functional study. Four functional traits were selected for the analyses. Our results showed that all studied facto…
Capteurs et images aériennes pour l’évaluation du peuplement de mauvaises herbes
2013
AIRINOV is specialized in use of UAV for precision agriculture. Thanks to a high spatial resolution up to 1.5 cm/pixel in RGB images, discrimination between vegetation (crop row, weed) and soil can be done. Variability can be detected in weed density inside the whole field. The detection of weeds in the inter-row of hoed row crops was tested on RGB images. The methodology developed is based on Hough transform, and is composed of three main steps: image segmentation, soil/vegetation discrimination and crop rows localization. First results are promising but need complementary measures for validation.
La régulation des adventices dans les systèmes de culture moins dépendants des herbicides : quels rôles de la fertilisation azotée et des caractérist…
2020
National audience; Is it possible to use nitrogen fertilization for weed control? Use of herbicides and mineral fertilizers must be reduced to make cropping systems more sustainable. These changes could lead to the development of a residual weed flora and an increased competition for resources, including nitrogen, between weeds and crops. This project aims at identifying which fertilization techniques and cultivar traits contribute to the biological regulation of weeds by modulating plant‐plant competition for nitrogen and thus help to reduce herbicide use, using a modelling approach (FLORSYS). The first step of the PhD project aimed at introducing plant‐plant competition for nitrogen into …
Effet d’une toile de paillage naturelle sur une culture de salade - rendement, etat sanitaire et faune du sol
2019
Le projet de stage c'est déroulé dans le cadre du projet PIA3 "Mulch Catalyse" coordonné par Fabrice L. Martin en partenariat avec l'entreprise "Géochanvre F" dirigé par Frédéric Roure. L'entreprise produits des toiles de paillages en fibres naturelles biodégradables dont l'usage permet, entre autres, de limiter la croissance des plantes adventices des cultures, notamment en maraîchage. Le sujet de stage portait sur l'étude de l'effet de plusieurs types de toiles de paillages sur la vie du sol en condition maraîchères, et de les comparer à un sol nue ou couvert de plastique
Le carabe, un prédateur au service de l’agriculture 2019
2021
National audience; Et si les carabes pouvaient être utilisés en tant qu’agents de lutte biologique contre les mauvaises herbes ? Une vaste étude sur l’alimentation de ces coléoptères dans différentes zones agricoles allant de la France à l’Autriche, montre que nombre de ces insectes seraient effectivement consommateurs des graines de mauvaises herbes. Les carabes sont des coléoptères appartenant à la famille des Carabidés. Il en existe près de 1000 espèces en France, certaines sont noires, d’autres sont colorées et leur taille varie du millimètre à plusieurs centimètres. Ils occupent presque tous les milieux et sont particulièrement nombreux dans les parcelles agricoles. Ils vivent sur ou s…
Simulateur de pulvérisation localisée d’herbicide
2019
Site-specific spraying is a technological lever to reduce the herbicide amount used in the case of chemical control of weeds. At the present time, detection and control technologies are available to apply herbicide only where weeds are present and thus provide an alternative to homogeneous application of chemicals on the entire surface of the field. In order to assess this practice, a digital simulator has been developed combining virtual infestation maps with different theoretical sprayer configurations. Simulations were used to localize herbicide applications and quantify herbicide reduction based on the spatial distribution of weeds and the width of independent spray units (boom sections…
Consequences of sown grass margin strip on weed flora
2010
The intensification of the management of weed populations, led by a potential decrease in the yield and quality of crop harvest, has largely induced their decline in arable zones across the last decades. This floristic decline in arable landscape, has induced a loss of a larger biodiversity because the presence of others organisms (birds, insects, mammals) are strongly linked with the abundance of trophic resources as weed are. To counter with this loss of biodiversity and to limit the negative impacts of farming practices on environment, numerous agri environmental schemes were launched through Europe. In France, sown grass strips were established by farmers along streams and rivers to lim…
Dynamique et assemblage des communautés adventices : Approche par modélisation statistique
2011
To develop solutions for a productive and sustainable agriculture, principles, theories, andmethods of ecology may contribute to understand the biological processes governing the agroecosystem.The present case study was based on data collected by a network of observatories of weeds covering the whole of France (‘Biovigilance Flore’) and aimed at establishing forrules governing the assemblage and dynamics of weed communities in fields grown with annual crops. We particularly studied the possible relationships between species within acommunity, as well as the relationships between communities and their environment. Analyses were based on species abundances to take account of their effect on c…
Raisonnement des pratiques et des changements de pratiques en matière de désherbage : regards agronomique et sociologique à partir d’enquêtes chez de…
2008
To ensure successful, more sustainable weed management practices, it is crucial to take account of farmer’s decision-making processes. Agronomists revealed that interviewed farmers had complex and various weeding programmes, and that, when designing these programmes, they integrated different time scales: the current year, the rotation, and the long term. They gave some light, too, on the decision-making processes and how it changes over time. Sociologists analyzed the way wine-growers bring about change from the cognitive angle and its bearing on interactive dialogue between the wine-growers themselves as well as with technical advisors