Know more

About cookies

What is a "cookie"?

A "cookie" is a piece of information, usually small and identified by a name, which may be sent to your browser by a website you are visiting. Your web browser will store it for a period of time, and send it back to the web server each time you log on again.

Different types of cookies are placed on the sites:

  • Cookies strictly necessary for the proper functioning of the site
  • Cookies deposited by third party sites to improve the interactivity of the site, to collect statistics

Learn more about cookies and how they work

The different types of cookies used on this site

Cookies strictly necessary for the site to function

These cookies allow the main services of the site to function optimally. You can technically block them using your browser settings but your experience on the site may be degraded.

Furthermore, you have the possibility of opposing the use of audience measurement tracers strictly necessary for the functioning and current administration of the website in the cookie management window accessible via the link located in the footer of the site.

Technical cookies

Name of the cookie


Shelf life

CAS and PHP session cookies

Login credentials, session security



Saving your cookie consent choices

12 months

Audience measurement cookies (AT Internet)

Name of the cookie


Shelf life


Trace the visitor's route in order to establish visit statistics.

13 months


Store the anonymous ID of the visitor who starts the first time he visits the site

13 months


Identify the numbers (unique identifiers of a site) seen by the visitor and store the visitor's identifiers.

13 months

About the AT Internet audience measurement tool :

AT Internet's audience measurement tool Analytics is deployed on this site in order to obtain information on visitors' navigation and to improve its use.

The French data protection authority (CNIL) has granted an exemption to AT Internet's Web Analytics cookie. This tool is thus exempt from the collection of the Internet user's consent with regard to the deposit of analytics cookies. However, you can refuse the deposit of these cookies via the cookie management panel.

Good to know:

  • The data collected are not cross-checked with other processing operations
  • The deposited cookie is only used to produce anonymous statistics
  • The cookie does not allow the user's navigation on other sites to be tracked.

Third party cookies to improve the interactivity of the site

This site relies on certain services provided by third parties which allow :

  • to offer interactive content;
  • improve usability and facilitate the sharing of content on social networks;
  • view videos and animated presentations directly on our website;
  • protect form entries from robots;
  • monitor the performance of the site.

These third parties will collect and use your browsing data for their own purposes.

How to accept or reject cookies

When you start browsing an eZpublish site, the appearance of the "cookies" banner allows you to accept or refuse all the cookies we use. This banner will be displayed as long as you have not made a choice, even if you are browsing on another page of the site.

You can change your choices at any time by clicking on the "Cookie Management" link.

You can manage these cookies in your browser. Here are the procedures to follow: Firefox; Chrome; Explorer; Safari; Opera

For more information about the cookies we use, you can contact INRAE's Data Protection Officer by email at or by post at :


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

Last update: May 2021

Menu Logo Principal Logo partenaire


Designing wheat varietal mixtures in organic agriculture

Mixtures of wheat varieties are a practice that is developing in France, as they contribute to stabilize production and reduce the use of pesticides. The CASABIO project focused on the rules necessary to design these mixtures, within the framework of organic agriculture.

Project title and acronym: Co-design of varietal associations for organic agriculture - CASABIO

Funded in the framework of the Call for projects "Innovation" 2017, the CASABIO project took place over 3 years (2017-2019).

Leaders: Jérôme Enjalbert (GQE - Le Moulon) and Arnaud Gauffreteau (Agronomy)

Non-academic partners: GAB IdF (Group for Organic Agriculture in Ile de France) and ITAB (Technical Institute for Organic Agriculture and Food)

croissance mélanges variétaux CASABIO

Adapting the variety to the growing conditions is a major lever to increase production in quantity and quality. This varietal lever is all the more important as the control of the growing environment by chemical inputs is limited, and therefore particularly strategic in organic farming (AB). However, the diversification of cultural practices, production objectives and the increase in inter-annual variability of crop conditions makes this choice difficult and sometimes impossible. Mixing several varieties in a plot at the time of sowing offers the farmer the possibility to cumulate characteristics of interest at the plot level and to increase the stability of his production in the face of an uncertain climatic and sanitary context by not putting all his eggs in the same basket. This practice has increased significantly in recent years (representing less than 3% of soft wheat acreage in 2015, it now occupies 12%).

Figure 1: Evolution of the area of mixed varieties in France

Faced with this growing practice, farmers and advisors lack rules of association to choose among the many varieties available those that will form a successful mixture, taking into account the methods of conducting these mixtures.
New fundamental and practical knowledge on plant-plant interactions in mixtures must be mobilized to better valorize these mixtures. The objective of CASABio was therefore to develop rules for the association of wheat varieties, focusing on nitrogen nutrition and weed control, two major constraints for AB production systems.

The 3-year project was built for and with organic farmers in Ile de France who participated in the design of association rules, in the choice of mixtures to be tested and in their experimentation on their farms.

A first result of CASABIO, following co-design workshops with farmers, agricultural advisors and scientists, was the development of heuristic (mental) maps. These maps list throughout the crop cycle the diversity of cultural practices and varietal characteristics related to each practice, which allow to control weeds and to favor nitrogen nutrition of wheat in organic agriculture.

Figure 1 CASABIO

Fig 2: Workshops to identify cultural practices and varietal levers to control weeds and nitrogen nutrition.

CASABIO figure 2

Following these workshops, various mixture assembly rules developed previously (Wheatamix Project) were reworked in CASABIO, notably by developing a simplified model of competition for light between varieties. Some of the rules developed (notably on disease resistance) have been integrated into a Multicriteria Evaluation Tool, OPTIMIX, which is available online. This tool was also the subject of a workshop with farmers and advisors.

Figure 3: Optimix, an online tool for evaluating on several criteria the qualities of a varietal mixture proposed by the user 

Finally, the rules produced were used to select variety mixtures that were evaluated in a network of AB experiments and by their implementation by GAB-IdF farmers in on-farm trials. These trials allowed to observe very contrasted production situations in organic farming (low to high productivity). The mixtures did not show a clear effect on weeds compared to pure varieties. On the other hand, nitrogen valorization and especially bread-making quality benefited from a positive mixture effect.

This work, original in its motivation and partnership, is currently being pursued in the CASDAR SSV STABLE and ANR PPR-CPA MoBiDiv projects.

Cover vidéo CASABIO

The project leader explains the project and its RESULTS in VIDEO (LabEx BASC scientific days, February 2021)