Teosinte, wild maize relatives originating from Mexico and Central America, emerged as a noxious agricultural weed in France and Spain. In 2016, the European Food Safety Authority (EFSA) issued a technical report that assessed the available scientific information on teosinte for its relevance for the environmental risk assessment (ERA) and risk management (RM) of genetically modified (GM) maize MON810, Bt11, 1507 and GA21 for cultivation. It was concluded that the impact of insect resistance and/or herbicide tolerance in GM teosinte hybrid progeny (potentially acquired through hybridisation between GM maize and teosinte) on target and non-target organisms, the abiotic environment and biogeochemical cycles would be very low under EU conditions. Following a request of the European Commission, EFSA evaluated whether the ERA conclusions and RM recommendations of EFSA (2016) remain applicable, or require revision in light of new scientific evidence on teosinte that has become available since the publication of EFSA (2016). A protocol was developed to clarify the interpretation of the terms of reference of the mandate and make them operational. The assessment relied on evidence retrieved via an extensive literature search and from reports of the Competent Authorities of France and Spain, and on hearing expert testimonies. A limited collection of 18 publications of varying relevance and quality was retrieved and assessed. Based on this evidence, it is concluded that the ERA conclusions and RM recommendations of EFSA (2016) remain applicable, except those pertaining to the use of glyphosate-based herbicides on maize GA21 which should be considered under Regulation (EC) No 1107/2009. In infested agricultural areas (especially in regions where maize MON810 is widely grown), weed management measures implemented to monitor, control and/or eradicate teosinte must remain in place, as they will contribute to further reduce the low vertical gene flow potential between GM maize and EU teosinte.
Update of environmental risk assessment conclusions and risk management recommendations of EFSA (2016) on EU teosinte