Genetically modified (GM) canola is appearing in farmers' fields where it wasn't planted, and because the plant has been engineered to resist conventional herbicides, it's tough to kill. "The GM canola has, in fact, spread much more rapidly than we thought it would," said Martin Entz, a plant scientist at the University of Manitoba. "It's absolutely impossible to control." Monsanto, which created one of the GM canola strains, says that if farmers call the company, they'll send out a team to manually pull up the weeds. But Martin Phillipson, a University of Saskatchewan law professor, said Monsanto may be liable for damages if their GM canola continues to spread.