Post market environmental monitoring of genetically modified herbicide tolerant crops (Working group report from the 4th international workshop on PMEM of genetically modified plants, Quedlinburg, Germany 2010)

According to European Union (EU) legislation, genetically modified (GM) crops released for commercial cultivation have to be monitored. Here we summarise the discussion of a working group that convened during the 4th International Workshop on Post Market Environmental Monitoring (PMEM) of Genetically Modified Plants in Quedlinburg from 3-4 May 2010 to discuss the necessity, extent and design of PMEM plans of genetically modified herbicide tolerant (GMHT) crops. The following workshop report summarises the questions specific to the monitoring of GMHT crops and seeks to answer what should be monitored and who should perform such a monitoring. In addition, the main challenges when monitoring GMHT crops are presented and it is discussed how these challenges could be addressed.