This global overview by Testbiotech documents several case studies showing how genetically engineered plants such as maize, rice, cotton, oilseed rape, bentgrass and poplar trees are spreading uncontrollably.

The release of genetically engineered trees into the open environment is an internationally disputed issue. Using genetically engineered poplars as an example, the following report gives clear evidence that it is not possible to adequately control the risks associated with the release of such trees, either in terms of space or time.