Search results for "Herb"
showing 10 items of 856 documents
Editorial: Chemical Ecology and Conservation Biological Control
2022
International audience
Fast changes in the morphology of the X-ray emitting shocks in HH 154
2006
Our recent second epoch Chandra observations have shown a fast morphological evolution of the X-ray source associated with the protostellar jet HH 154 (Fig.\ 1). We propose to study the evolution of the optical structures in the jet, specially the ones associated with the X-ray emission with a monitoring program of imaging narrow and broad band optical observations. We will determine the proper motions (and braking) of the optical knows associated with shock features and the evolution of their line luminosity and therefore their cooling time. These data, together with our past and future X-ray observations, constitute a fundamental input and constraint to our parallel program of ongoing hyd…
Dual action of phosphonate herbicides in plants affected by herbivore—Model study on black bean aphid Aphis fabae rearing on broad bean Vicia faba pl…
2008
Abstract The interactions between plants, herbicides and herbivore insects were studied as an aspect of possible side effect of the using of phosphonate herbicides. The experimental system was composed of phosphonate herbicides, broad bean Vicia faba (L.) plants and black bean aphid Aphis fabae (Scopoli). Two means of herbicide application, namely standard spraying and direct introduction of the herbicide into stem via glass capillary, were examined. The results obtained for N-2-piridylaminomethylene bisphosphonic acid and its derivatives show 10 times higher inhibition of the plant growth if glass capillary mode was used. When plants were infested by aphids 24 h after the use of herbicide,…
Intorno alla sociologia dei problemi sociali
2019
Il saggio ricostruisce le diverse prospettive di ricerca sociologica che si sono sempre interrogate sulle cause, le condizioni, le conseguenze e le soluzioni dei problemi sociali, a partire dalla categorizzazione medesima del concetto. The essay reconstructs the different perspectives of sociological research that have always questioned the causes, conditions, consequences and solutions of social problems, starting from the very categorization of the concept.
Biodegradation of pesticides by soil microflora
2006
SHORT-TERM RESPONSE OF SOIL MICROORGANISMS TO ESSENTIAL OILS WITH ALLELOPATHIC POTENTIAL EXTRACTED FROM MEDITERRANEAN PLANTS
2015
Essential oils (EOs) with allelopathic compounds have been used to reduce or avoid weed germination and growth. The aim of this study was to evaluate the potential phytotoxic effects of EOs extracted from different Mediterranean plants on soil microbial biomass and activity. EOs were extracted from leaves of Eucalyptus camaldulensis Dehnh (EUC); Eriocephalus africanus L. (ERI); Thymus capitatus (L.) Hoffmanns. & Link (TCP); Citrus reticulata Blanco var. ‘Clemenules’ (TAN) and Citrus limon (L.) Osbeck var. ‘Eureka’ (LEM). Each EO was supplied to pots containing 560 g of soil at three different doses (low, medium, high). After 15, 30, 90, 120 days the supply of EOs, soils were destructively a…
Résistances aux herbicides : au Nord, c’étaient les Laiterons !
2016
SPEGESTAD; Contexte - Après des échecs de désherbage de laiteron épineux à l’aide d’herbicides inhibiteurs de l’ALS (groupe HRAC B) en culture d’endives, l’hypothèse de la présence d’une résistance à ces herbicides a été étudiée. étude - Des tests biologiques avec un herbicide du groupe B (rimsulfuron) ont été effectués sur des populations provenant de parcelles « à problème ». Le gène de l’ALS a également été séquencé afin de rechercher la présence de mutations causant une résistance aux herbicides inhibiteurs de l’ALS dans ces populations. résultats - Les tests biologiques ont montré l’existence d’une résistance au rimsulfuron dans les trois parcelles étudiées. Des mutations au codon 197 …
Adaptation to stressful environments : invasion success of the Colorado potato beetle (Leptinotarsa decemlineata)
2018
Biological invasions, specifically human-induced dispersals, are one of the major threats to our biodiversity and are predicted to increase. Invasive pests provide an opportunity to study whether adaptation to human-induced environments could promote invasions to other human-induced environments. One major anthropogenic selection pressure is created by pesticides, and pests can be exposed to various pesticides in their native, as well as introduced, ranges. I investigated whether exposure to anthropogenic selection (i.e. insecticides and herbicides) and exposure to multiple anthropogenic stressors selects for higher stress tolerance. I also tested whether parental prolonged diapause or inse…
CSI 2264: Simultaneous optical and X-ray variability in the pre-main sequence stars of NGC 2264
2019
Context. Pre-main sequence stars are variable sources. In diskless stars this variability is mainly due to the rotational modulation of dark photospheric spots and active regions, as in main sequence stars even if associated with a stronger magnetic activity.Aims. We aim at analyzing the simultaneous optical and X-ray variability in these stars to unveil how the activity in the photosphere is connected with that in the corona, to identify the dominant surface magnetic activity, and to correlate our results with stellar properties, such as rotation and mass.Methods. We analyzed the simultaneous optical and X-ray variability in stars without inner disks (e.g., class III objects and stars with…
La nuisibilité directe des adventices en grandes cultures : quelles réponses nous apportent les essais désherbages ?
2016
The direct harmful effect of weeds in field crops : what do herbicide trials tell us ? Weeds are plants whose undesirable qualities (“harmfulness") outweigh their desirable qualities (trophic resources). Few studies conclude that weeds do not affect crop yield. However, it is difficult to generalize since weeds compete with crops for resources and these resources are spatially and temporally variable. This study analyzed 110 herbicide trials (untreated vs. treated plots) performed in France from 1993 to 2015 on three major grain crops: winter wheat, winter oilseed rape and sunflower. Significant yield losses were found in 92% of wheat trials (average over all trials: -2.6 t/ha), 51% of wint…