GM crops have created superweeds

Super weeds 'run rampant in fields near GM crops'.
GM crops have failed to deliver higher food yields but have created dangerous super weeds, a report warns. Health and conservation groups from Africa, Asia and Latin America say that the fast-growing weeds smother other crops planted in fields near where GM crops have been grown.
Read article in the Daily Mail (UK)

“Superweeds” are plaguing high-tech Monsanto crops in southern US states

See Superweed explosion