Search results for "PEST"

Analyse des effets du paysage et des abondances régionales de bioagresseurs sur les niveaux d’usage phytosanitaires en grandes cultures et polycultur…

2021

National audience; L’utilisation massive de pesticides en agriculture engendre des problèmes environnementauxet sanitaires. Le plan Ecophyto II lancé en 2015 ambitionne une réduction de l’usage depesticides grâce d’une part à la généralisation et à l’optimisation des techniques identifiéescomme favorables à cette réduction et d’autre part à l’initiation de changements profonds dessystèmes de cultures et des filières. L’enjeu de la thèse est d’identifier des systèmes de culturesqui permettent de réduire la dépendance aux produits phytosanitaires mais aussi de biencomprendre les conditions de contextes paysagers et de pressions de bioagresseurs danslesquels ces systèmes sont performants. La d…

Pesticides : la France peut-elle en sortir ?

2020

International audience; Au lieu de baisser, la consommation de pesticides ne fait quegrimper en France. Comment l'expliquer ? Et peut-on encorecroire au plan Ecophyto ? Science & Vie a posé la question auspécialiste de l'agroécologie Xavier Reboud (INRAE).Les résultats du plan gouvernemental Ecophyto, visant à réduire l’utilisation desproduits phytosanitaires dans l’agriculture, sont tombés il y a quelques jours. Et ilssont désespérants : entre 2017 et 2018, les quantités de substances activesvendues se sont envolées de 21% (dont +11% pour le glyphosate). Soit une haussede 22 % entre la période 2009-2011 et 2016-2018, alors que le programmeEcophyto vise tout au contraire une réduction des u…

DIVERSITE GENETIQUE ET PHENOLOGIE DE CYPERUS ESCULENTUS L. (CYPERACEAE) POUR UNE GESTION INTEGREE DE L'ESPECE DANS LES CULTURES DE HAUTE LANDE

2006

We studied the development, phenology, demography and genetic diversity of Cyperus esculentus (Cyperaceae), an invasive clonal perennial weed in the small-statured crops of Haute Lande, southwestern France. The goal was to understand its colonizing capacity and then make propositions for an integrated management of the species.The colonizing capacity of C. esculentus is linked to the huge subterranean vegetative development, with both foraging thanks to rhizomes and multiplication thanks to tubers. On the other hand, the local crop systems provide all the needs of the species: water, light and nutriments without competition by other weeds. Genetic analyses showed a low genetic diversity and…

A modeling approach to evaluate the influence of spatial and temporal structure of an epidemiological surveillance network on the intensity of phytos…

2017

National audience

Why farmers consider pesticides the ultimate in crop protection: economic and behavioral insights

2018

International audience; The observed dependence of current crop production on chemical crop protection is largely due to economic and technological factors. High yield and specialized cropping systems require high crop protection levels and pesticides allow achieving such protection levels at reasonable (private) costs. The main aim of this article is to show that behavioral factors may reinforce the effects of these economic and technological factors on farmers considering pesticides the ultimate in crop protection. Choice mechanisms described by K?szegi and Rabin (2007) imply that individual attitudes toward a given risk are endogenous in the sense that they depend on the best available m…

Sortie des pesticides: l’agriculture face à sa nécessaire révolution

2019

International audience; L’agriculture pourra-t-elle se passer de pesticides de synthèse en 15 ans? Au-delà des aspects techniques, c’est tout le système agricole, du champ à l’assiette, qui s’en trouverait bouleversé. Face à des blocages tenaces, le JDLE a fait le point avec le chercheur Xavier Reboud, spécialiste d’agroécologie.

L'INRA prépare activement l'agriculture de demain

2018

National audience

Identification of bound alcohols in soil humic acids by gas chromatography-mass spectrometry

2000

International audience; Humic acids are complex, partly macromolecular, yellow-brownish substances occurring in soils, waters and sediments. In order to shed some light on their molecular structure, crop humic acids were cleaved by alkaline hydrolysis (KOH). The products were fractionated by thin layer chromatography to give mono-alcohols which were analysed as acetate derivatives by gas chromatography coupled to mass spectrometry. Linear alcohols, sterols, stanols and plant-derived triterpenoid alcohols were identified by co-injection of pure standards and by comparison with literature data. These findings imply that alcohols could have been incorporated into the humic matrix by esterifica…

Pestizid-Gemische sind für Bienen schädlicher als angenommen

2021

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