A scientific study of the United States' genetically modified cotton crop has found out of control weeds are costing farmers in lost production.
The weed, known as Palmer's pigweed, has developed a strong resistance to the herbicide glyphosate, which is used to control weeds.
It can grow so big it damages harvesting equipment and often has to be removed by hand.
The study's lead author Dr Todd Gains from the University of Western Australia says Australian GM canola growers could avoid the same problem.
"It's important that the principles for how this happened could be repeated, but it's a mistake that would have to happen consciously," he says.
"If you have any situation where you use the same herbicide every year with no other control options, certainly resistance can evolve."
"It'll be important for Australian farmers to use GM technology appropriately."
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