GM Cropwatch's Jessica Harrison says she has found GM canola plants heaped up on the roadside near Horsham, and that galahs were also seen feasting on GM canola last week.

She says windrowed GM canola plants also blew off a farmers' property and were strewn 75 metres across the road.

"Agriculture Minister Joe Helper must apply strict pollution laws to this GM harvest, monitor and manage all the GM sites and clean up this GM contamination," Ms Harrison said.

"He must also ensure that all GM canola cut for hay is used where it stands or is destroyed, instead of spreading viable seed across the country-side."

Cropwatch has monitored and tested for GM canola spills on roadsides and farms around Horsham and the Lubeck silo for the past two weeks.

Geoffrey Carracher, of the Network of Concerned Farmers, says that after windrowed canola is cut and laid down to dry "wind gusts often lift up whole rows and dump the plants metres or even miles away".

Mr Carracher claims the GM contamination is now "rampant", even though "just fifteen farmers will deliver GM canola to the Lubeck silo this year".