Search results for "Conservation"
showing 10 items of 2328 documents
Landscape scale and local crop protection intensity affect the abundance of the codling moth and its predation and parasitism in apple orchards
2017
International audience; One important feature that may explain variation in pest abundance and pest biocontrol in crops is the land-use intensity in the landscapes. We report results from three studies in which we tried to address this question by assessing whether amount of semi-natural habitat and/or pesticide use at both local and landscape scales affected the abundance of codling moth, its parasitism and predation of sentinel eggs in commercial apple orchards of south-eastern France. Our results indicate that in this landscape there is indeed a significant effect of the pesticide use intensity at both the local and the landscape scales on these variables
La collection de semences adventices de l’UMR Agroécologie (Dijon)
2019
National audience; Les semences adventices peuvent survivre dans le sol durant de nombreuses années. Le stock semencier constitue ainsi un point fondamental du développement des communautés adventices, en lien avec leur stratégie de survie. Son étude apparaît donc comme un point crucial dans la compréhension de la dynamique des adventices. Au sein de l’UMR Agroécologie, des travaux sont menés pour étudier différents processus biologiques liés au cycle de vie des adventices, les phénomènes de résistance des adventices aux herbicides ainsi que les interactions entre les adventices et d’autres organismes (prédation des graines par des insectes par exemple). Pour soutenir ces activités de reche…
[CA-SYS] Des essais de couverts d’interculture en semis direct pour réguler les adventices (1). Article internet posté sur le site de la revue Sésame
2019
National audience
[CA-SYS] Avec les agriculteurs, mettre de l’ambition et du réalisme dans les questions de recherche en agroécologie
2019
National audience
Disentangling local agronomic practices from agricultural landscape effects on pest biological control
2019
International audience; The biological control of crop pests is a valuable service provided by various beneficial organisms that are naturally present in agricultural landscapes. Semi-natural habitats has long been recognized as essential to preserve beneficial insects, but proof of their efficiency to enhance biological control of pests remains non conclusive. Here, we examined the variability of landscape effect on biological pest control and the way local agronomic practices may modulate it. Biological pest control was monitored in 80 commercial fields (arable crops and orchards) during three consecutive years in four contrasting French agricultural landscapes distributed along a double …
Et si une impasse de désherbage en Agriculture de Conservation vous poussait à retravailler le sol ? Quelle intervention choisiriez-vous ?
2019
National audience; Il est admis que la perturbation minimale du sol est l’une des trois règles d’or en agriculture de conservation des sols (ACS). Si l’impasse se fait sentir (adventices dominantes difficiles à gérer, voire résistantes), mieux vaut repenser le système que de laisser le mur se rapprocher à grands pas. Repenser la place du travail du sol, de manière exceptionnelle dans des systèmes en semis direct sous couvert, est déjà envisagé au Canada et aux États-Unis. L’Inra de Dijon a testé trois types de travail du sol sur des parcelles conduites en ACS depuis 17 ans.
Un mystère : la technique de conservation mise en oeuvre par Honoré Fragonard pour créer ses fameux écorchés
2008
A two part overview of the techniques used by Honoré Fragonard to create and preserve (mainly against the insects) cutaway anatomical figures (" écorchés ") of animals or humans. The first part summarise the techniques preparing the dry anatomical specimens at that time, according to contemporary bibliographical data: selection and preparation of the bodies, then injection of the various organs and tissues (e.g: muscles, nerves, lymph and blood vessels, placenta etc.). The second one gives detailed information on the techniques used by Fragonard to create his " écorchés " : selection of the subjects, highlighting the various organs and tissues, mummification, drying and varnishing. This new…
Modeling small‐scale cassava starch extraction. Simulation of the reduction of water consumption through a recycling process
2010
International audience; The purpose of this study was to model the extraction unit operation of the cassava starch manufacturing process and to propose a realistic recycling simulation in order to reduce the volumes of effluents. The model was developed from reactors which are commonly used for cassava starch extraction at a household scale in Vietnam. The reactors were tested using inflow starch as a marker at the beginning of the batch process. The experimental residence time distribution (RTDexp) was calculated by the outflow of the starch concentration. Using Matlab®, the RTDexp was compared to the theoretical residence time distribution (RTDth). The dynamic model obtained was built up …
Weed seeds ability to emerge on the soil surface
2015
International audience; Annual weeds have to produce seeds each year to maintain their populations. These seeds fallon the soil surface. Seeds exposed to light during their moistening (i.e. caused by rain) bettergerminate than seeds in the darkness (i.e. buried). However, rare studies quantified the unique andcombined effects of light, moisture and burial depth on the germination process. We investigated,in a greenhouse experiment in 2014, the impact of seed moisture (Moistened vs. Dried), lightduring moistening (Darkness vs. Light) and burial depth (Buried vs. Surface) on germination of 12annual weed species contrasted on their seed traits and germination periods (Alopecurusmyosuroides Hud…
Phenotypic and genetic variability in Forest thrush, Turdus lherminieri at different scales
2012
Understanding the mechanisms underlying population structure is a crucial issue in evolutionary biology and ecology. Identifying the processes driving biodiversity is also of prime interest to draw up guidelines for population management and conservation planning. Level of differentiation depends on a subtle balance between gene flow, genetic drift and natural selection and insight into the relative contribution of these factors can be provided by spatial and temporal patterns of intra-specific phenotypic and genetic variations. Differentiation has mainly been studied in insular systems because i) islands give ideal framework to study divergence in species ii) islands enclosed endemic fauna…