Search results for "oilseed rape"
showing 10 items of 14 documents
A preliminary approach for modelling the effects of cropping systems on the dynamics of broomrape ( Phelipanche ramosa) in interaction with the non-p…
2011
International audience; The current decrease in herbicide use may increase and diversify weed flora in crops as well as companion bioagressors spreading via weeds. Among these bioagressors is Phelipanche ramosa (L.) Pomel, a parastic plant which is very harmful on oilseed rape. The objective of the present work was to develop a new model (called PheraSys) of the effects of cropping systems on parasite dynamics, in interaction with non-parasitic weed hosts. The structure of this first model version was based on models developed for other parasitic plants and on FlorSys which quantifies the effects of cropping systems on non-parasitic weed flora. PheraSys was parametrized with preliminary val…
Using the GENESYS model quantifying the effect of cropping systems on gene escape from GM rape varieties to evaluate and design cropping systems.
2004
Gene flow in rapeseed is a process taking place both in space and over the years and cannot be studied exclusively by field trials. Consequently, the GENESYS model was developed to quantify the effects of cropping systems on transgene escape from rapeseed crops to rapeseed volunteers in neighbour plots and in the subsequent crops. In the present work, this model was used to evaluate the risk of rape harvest contamination by extraneous genes in various farming systems in case of co-existing GM, conventional and organic crops. When 50 % of the rape varieties in the region were transgenic, the rate of GM seeds in non-GM crop harvests on farms with large fields was lower than the 0.9 % purity t…
Potential impact of genetically modified Lepidoptera-resistant Brassica napus in biodiversity hotspots: Sicily as a theoretical model
2016
The general increase of the cultivation and trade of Bt transgenic plants resistant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape (Brassica napus L.), including transgenic lines. In environmental risk assessments (ERAs) for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non-target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or naturalization of spilled seed in Sicily (Italy). Diurnal Lepidoptera, which are pollinat…
Ex Ante evaluation of gene flow in oilseed rape with cropping system models
2013
Chapitre 4; Oilseed rape (OSR) genes can escape fields in space via pollen and seeds, and in time via volunteers resulting from seeds lost before or during oilseed rape harvest. When varieties co-exist, e.g. genetically-modified (GM) and non-GM varieties, this spatio-temporal gene flow can lead to the adventitious presence of GM seeds in non-GM harvests and thus cause financial losses for farmers and cooperatives. Gene flow depends on crop locations, succession, and management, as well as the location and management of semi-natural areas such as roadverges. The objective of this investigation was to present a simulation methodology using the spatially-explicit cropping system model GENESYS …
Contribution des pollinisateurs dans la production de colza et de tournesol en zone atelier « Plaine et Val de Sèvre »
2018
Insect pollination is essential for over 70% of crops around the world. However, the contribution of pollinators to crop production and the insects involved in crop pollination have rarely been studied. Moreover, assessments of pollinator contributions have mostly been conducted on a small scale or under simplified conditions, which do not represent the real contributions at the field scale and do not take into account possible interactions between pollinators and farming practices. The aim of this study is to quantify directly under field conditions, the contribution of pollinators in two crops frequently cultivated in Europe: oilseed rape and sunflower. Estimations are realized both at th…
How to manage the impact of gene flow on oilseed rape grain quality? Simulation case studies of three contrasted landscapes
2012
Abstract Grain admixture due to gene flow of oilseed rape (OSR) could be economically damaging. Different strategies are currently used or proposed to manage grain quality, ranging from homogenisation at the silo level to tactical decision rules at the field level. The relevance of these general strategies was appraised in the case of genetically modified (GM) OSR in three contrasted regions in Europe: Beauce Blesoise (France), Schleswig-Flensburg (Germany), and Fife (UK). Field patterns, crop allocation and agricultural practices were derived from existing datasets and complementary field surveys. Then a gene flow simulator was used to assess how the local contexts influenced the grain adm…
Modelling the effects of cropping systems on the dynamics of a parasitic weed, Phelipanche ramosa, in interaction with the non-parasitic weed flora
2010
International audience; The current decrease in herbicide use may increase and diversify weed flora in crops as well as companion bioagressors spreading via weeds. Among these bioagressors is Phelipanche ramosa, a parastic plant which is very harmful on oilseed rape. The objective of the present work was to develop a model (called PHERASYS) of the effects of cropping systems on parasite dynamics, in interaction with non-parasitic weed hosts. The structure of the first model version was based on models developed for other parasitic plants and on FLORSYS which quantifies the effects of cropping systems on non-parasitic weed flora. PHERASYS was parametrized with preliminary values from literat…
Différences de capacités d’induction de la germination de deux pathovars d’orobanche rameuse sur une gamme d’hôtes des familles des brassicacées et f…
2016
Branched broomrape (Phelipanche ramosa (L.) Pomel) is a holoparasite weed causing significant yield losses on several crops, especially in France on winter oilseed rape fields. The ability to induce germination of seeds of branched broomrape, variable between host species, represent an important information to identify the status of weed species present in the crop (host or non-host). In this study, conducted in in vitro conditions, we focused on two botanical families and two dominant pathovars of branched broomrape in France. We show that the host species is the only important explanatory factor of seed germination rate, the latter being not affected by the pathovar. Among the species stu…
Ex ante evaluation of gene flow in oilseed rape with cropping sytem models
2009
International audience
Spatio-temporal dynamics of weed seed eating carabid species in agricultural mosaics: variation of annual habitat quality of oil seed rape and role o…
2017
National audience; Carabid beetles are considered as important contributors to the regulation of weeds and recent studies have shown that weed seed predation by carabids may partly substitute for herbicide use in agriculture. Enhancing this ecosystem service requires to understand the spatio-temporal distribution of these species during the cropping season. Infra-annual variation in the spatial distribution of ground beetles within agricultural mosaics is less documented but of prime importance given that agricultural landscapes are highly dynamics. Indeed, crop phenology, agricultural operations but also habitat requirements during life cycle can lead to a redistribution of individuals bet…