Search results for "herbicide"
showing 10 items of 273 documents
Les adventices réduisent le rendement et la réduction d'usage d'herbicides aggrave cette perte si elle n'est pas compensée par des mesures préventive…
2017
EAGESTAD INRA; Cette étude analyse les relations entre usage d'herbicides, infestation d’adventices et pertes de rendement en parcelles d'agriculteurs, via la simulation. Nous avons simulé 255 systèmes de culture d'agriculteurs de 7 régions avec une flore adventice régionale, puis sans adventices, et enfin sans herbicides. Les résultats montrent que (1) la perte de production augmente avec la biomasse adventice, (2) il n'y a pas de relation entre IFT herbicide d'une part, biomasse adventice et perte de rendement d'autre part parce que les agriculteurs prennent des mesures compensatoires lorsqu'ils réduisent l'usage d'herbicides, (3) la perte de rendement et la nuisibilité liée aux adventice…
Les phytoprotecteurs (« Safeners ») associés aux herbicides jouent-ils un rôle dans la sélection de résistances non liées à la cible ?
2016
Do herbicide-associated "Safeners" play a role in the selection for non-target-site resistances ? To ensure or improve crop selectivity, some herbicide molecules are applied in association with a “safener”. Safeners are compounds that, at the rate applied, enhance herbicide-degrading metabolic pathways supposedly specifically in crop plants. The metabolic pathways enhanced by safeners in crop plants are highly similar to those exacerbated in taxonomically closely related weed species that evolved non-target-site based resistance (NTSR) to herbicides. Herein, we show an enhancing effect of herbicide safeners on NTSR in a major noxious grass weed: rye-grass (Lolium sp.).
Robotics for weed control: I-Weed Robot for a specific spraying
2012
International audience; To preserve environment for a sustainable agriculture, we explore the development of a new autonomous robot, called I-Weed Robot (Intelligent Weed Robot), which aims at reducing herbicides in crop fields (maize, sunflower...). Using a high precision positioning signal (RTK) to locate the robot in the field, a Kaman filter and a proportional-integral-derivative controller (PID controller) allow adjusting the orientation of the robot depending on a predefined trajectory. As for the spraying system, a camera in front of the mobile platform detects weed plants thanks to an image processing based on a crop/weed discrimination algorithm (Hough Transform). At the back a spr…
Caractérisation de la réponse transcriptionnelle du vulpin des champs (Alopecurus myosuroides) à des herbicides inhibiteurs de l’acétyle-coenzyme A c…
2014
L’objectif de cette thèse était d’étudier les mécanismes génétiques de la résistance non liée à la cible à des herbicides appartenant aux groupes des inhibiteurs de l’acétyl-coenzyme A carboxylase (ACCase) et de l’acétolactate synthase (ALS) chez le vulpin des champs (Alopecurus myosuroides Huds.), une graminée adventice non modèle d’importance agronomique. Deux méthodes de transcriptomique ont été employées : l’hybridation soustractive suppressive (SSH) et le séquençage de transcriptome complet (RNA-seq). La SSH a permis d’identifier des transcrits potentiellement en cause dans la RNLC au fénoxaprop, à l’haloxyfop (inhibiteurs de l’ACCase) ou au pyroxsulame (inhibiteur de l’ALS). La surexp…
Evolution of herbicide resistance in mugwort (Ambrosia artemisiifolia L.): search for genetic determinisms and application to molecular diagnosis
2022
Common ragweed (Ambrosia artemisiifolia L.), a particularly troublesome and allergenic weed, is mainly controlled in agricultural fields using ALS inhibitor herbicides. Recent cases of herbicide resistance have been reported in France and are jeopardising the efficacy of this mode of action. Both target site resistance (TSR, structural mutation in ALS gene) and non target site resistance (NTSR, regulatory and/or structural mutations in secondary metabolism) are involved. The fundamental aim of this work was to identify the genetic determinisms of resistance to ALS inhibitors that have evolved in common ragweed populations in France. As an applied objective, this work also aimed to prepare t…
Recent advances in the research on herbicidally active aminomethylelebisphosphonic acids.
1999
Influence of the mode of application of herbicidally active N-pyridylaminomethylenebi-sphosphonic acids on their uptake by plants was studied in some detail. The experimental evidence is given that accounts for a multiple mode of action of these herbicides.
Impact of Leptospermone, a Natural β-Triketone Herbicide, on the Fungal Composition and Diversity of Two Arable Soils
2019
International audience; Impact of leptospermone, a β-triketone bioherbicide, was investigated on the fungal community which supports important soil ecological functions such as decomposition of organic matter and nutrients recycling. This study was done in a microcosm experiment using two French soils, Perpignan (P) and Saint-Jean-de-Fos (SJF), differing in their physicochemical properties and history treatment with synthetic β-triketones. Soil microcosms were treated with leptospermone at recommended dose and incubated under controlled conditions for 45 days. Untreated microcosms were used as control. Illumina MiSeq sequencing of the internal transcribed spacer region of the fungal rRNA re…
Impact of Leptospermone, a Natural β-Triketone Herbicide, on the Fungal Composition and Diversity of Two Arable Soils
2019
Impact of leptospermone, a β-triketone bioherbicide, was investigated on the fungal community which supports important soil ecological functions such as decomposition of organic matter and nutrients recycling. This study was done in a microcosm experiment using two French soils, Perpignan (P) and Saint-Jean-de-Fos (SJF), differing in their physicochemical properties and history treatment with synthetic β-triketones. Soil microcosms were treated with leptospermone at recommended dose and incubated under controlled conditions for 45 days. Untreated microcosms were used as control. Illumina MiSeq sequencing of the internal transcribed spacer region of the fungal rRNA revealed significant chang…
Phytotoxic effects of commercial essential oils on selected vegetable crops: Cucumber and tomato
2020
Abstract Essential oils of Origanum vulgare L., Rosmarinus officinalis L., Thymus mastichina L., Ocimum basilicum L., Melaleuca alternifolia Maiden & Betche ex Cheel, Eucalyptus globulus Labill., Gaultheria procumbens L. and Origanum majorana L., with herbicidal effects at different doses (0.125, 0.250, 0.50 and 1 μL/mL) were tested against Cucumis sativus L. and Solanum lycopersicum L., in order to ensure their harmlessness against these Mediterranean food crops. Oregano (carvacrol 60.42%) was the most damaging essential oil, exhibiting a dose-dependent phytotoxic activity against the seed germination and seedling growth of cucumber and tomato, whereas rosemary (1,8-cineole 24.95%, camphor…
Atrazine uptake, elimination, and bioconcentration by periphyton communities and Daphnia magna: effects of dissolved organic carbon.
2001
The bioconcentration and toxicokinetics of atrazine in three different periphyton communities and in laboratory reared Daphnia magna were studied in natural and artificial waters with different dissolved organic carbon (DOC) concentrations and qualities. The exposure concentrations were similar to those short-lived peak concentrations found in contaminated waters. Atrazine uptake and elimination were very fast, and the bioconcentration was low both in periphyton and D. magna. The bioconcentration factors in D. magna were approx. 16% of those in periphyton. The uptake and elimination rates were also higher in periphyton than in Daphnia. The periphyton properties affected the bioconcentration…