Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free:

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site:, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Google Analytics

Targeted advertising cookies


The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at or by post at:

24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal AgroParisTech université Paris-Saclay

Welcome to ECOSYS

UMR ECOSYS - Ecologie fonctionnelle et écotoxicologie des agroécosystèmes

Poster 3 : Colza_densite

Poster 3 : Colza_densite.
A. Mathieu, A. Julien, J.M. Allirand, M. Bidon, F. Duhamel

Caracterization of Winter Oilseed Rape response to density and initial conditions


Plant plasticity is the capacity for a plant to adapt to its environmental constraints. A better understanding of winter oilseed rape plasticity may help to explain plant functioning and to predict plant behaviour in a changing environment. Due to this plasticity, there is a great variability between plants within a crop expressed by different features of architecture, among which the number of leaves and branches. Our objective is to understand how this variability takes place. In this article, we focus on the vegetative part of the crop cycle and simple architectural variables

One cultivar (Pollen) have been grown in ten square containers in order to control growth conditions (Grignon, France, 2012-2013). Plants were sowed in buckets and transplanted two weeks later at two densities with a regular distribution pattern. At the highest density, there was two treatments: homogenous and heterogeneous. The pattern of distribution of heterogeneous plants was predefined in order to study different types of neighbourhood. Once a week from September 2012 to April 2013, the number of leaves by plant was counted and plants were photographed to compute green surface area. Besides, four destructive measurements have been carried out: initial stage, end of winter, end of branch appearance, flowering stage.

A great variability in the leaf dynamics was observed even within a pot, whatever the treatment. The number of final leaves ranges from 14 to 32. Considering only the heterogeneous experiment, initial plant size explained 30% of the variability of final leaf number. There is a significant effect of the initial size on phyllochron too. The ranking of plant phyllochrons remained constant over time, meaning the heterogeneity was maintained during the growth, without visible rebalancing effects between plants. Next step of this work is to study neighbourhood effect between plants using photographies. This study may help to better understand interactions between plants within the crop. These results will be used to validate a functional-structural plant model of WOSR and extend it from individual plant to population of plant level.