<i>Bt</i> maize: a tool for improving food safety of grains at harvest

  • C. Regnaut-Roger Université de Pau et des Pays de l'Adour - UMR CNRS 5254 IPREM - EEM - IBEAS BP 1155 - 64013 Pau. Email: catherine.regnault-roger@univ-pau.fr
  • L. Folcher Université de Pau et des Pays de l'Adour - UMR CNRS 5254 IPREM - EEM - IBEAS BP 1155 - 64013 Pau
  • M. Delos Ministère de l’Agriculture et de la Pêche - Service Régional de la Protection des Végétaux - “Midi-Pyrénées" - Bât. E - Bd Armand Duportal - F 31074 Toulouse
  • M. Jarry Université de Pau et des Pays de l’Adour - UMR 1224 ECOBIOP, IBEAS BP 1155 - F-64013 Pau; INRA, UMR 1224 ECOBIOP, F-64310 Saint-Pée sur Nivelle
  • A. Weissenberger Chambre d’Agriculture du Bas-Rhin - Filières végétales - 2 route de Rôme - BP 30022 Schiltigheim - 67013 Strasbourg cedex
  • N. Eychenne Fédération Régionale de Défense contre les Organismes Nuisibles- FREDEC Midi-Pyrénées, Bt 43, 2 route de Narbonne, B.P.12267- F 31322 Castanet Tolosan


A new EU (European Union) regulation came into force in 2007 with Regulation (EC) No. 1126/2007 which established maximum levels for fumonisins B1 and B2 (4000 ppb), deoxynivalenol (1750 ppb) and zearalenone (350 ppb) in maize and maize products. In order to evaluate French maize food safety, studies were carried out by the national Biological Risk Monitoring (BRM) Network. In this study, field trials involving 84 plots were conducted with Bt maize (MON 810) and its isogenic non-Bt counterpart in 2005 and 2006 in South-western France. Mycotoxin levels were determined in grain at harvest. Fumonisins B1 and B2, deoxynivalenol, and zearalenone were analyzed by LC-MS-MS and the results treated statistically using non parametric tests for mycotoxins and analysis of variance test for weather variables. As the climate was homogenous inside the experimental area, the transgenic event introduced into the maize was the only key parameter which differed between Bt and non-Bt maize plots. Our results showed that all mycotoxin families were not impacted in the same way. The efficacy of Bt maize reduced mycotoxins more than 90% for fumonisins and more than 50% for zearalenone although deoxynivalenol was lightly increased. Therefore a competition between the different Fusarium spp. which produced fumonisins or trichothecenes is hypothesized. According to Regulation (EC) No. 1126/2007, 93% of the maize of Bt maize plots were able to be commercialized compared to only 45% for non-Bt maize plots. The results of this work showed that Bt maize improved food safety and constituted an useful tool to reduce significantly mycotoxin levels in harvested and stored grains.

Keywords: Bt (MON810) maize, Fumonisins B1 and B2, Deoxynivalenol (DON), Zearalenone, EC regulation 1126/2007 thresholds