The GM crop trial programme in Britain has been thoroughly undermined by a new investigation into the use of weedkillers by US farmers growing GM crops, says environmental pressure group Friends of the Earth (FoE).  The claim follows yesterday's [Tuesday] BBC "Newsnight" investigation. Although the GM trials in Britain involve the exclusive use of glufosinate ammonium (GA), farmers growing the same crop commercially in the US have resorted to a mix of GA and the far more damaging weedkiller Atrazine.