Next month, US farmers will visit NSW, VIC, SA and Western Australia to share their experiences and concerns of genetically modified (GM) crops.

The "Seeds of Doubt" tour has been organised by a network of Australian farmers from the major grain growing regions of Australia. In a communique they explain: "We, like many farmers, are concerned about the potential economic and environmental impacts of GM crops."

Speakers include Canadian Percy Schmeiser, a canola farmer who was ordered by the Canadian court to pay Monsanto for breaching their patent when GM canola was found in his 1998 crop; and Gail and Tom Wiley, North Dakota grain farmers, who lost a major export contract to Japan through GM contamination of their crop.

Juliet McFarlane, a broad acre canola and wheat farmer from Young, insisted: "The Canadian experience shows that five years after the introduction of GM canola, segregation is no longer possible. As a direct result of that contamination, Australia has gained market access into Asia and Europe and Australia's GM-free status has given us a much needed competitive edge over other canola producers."

McFarlane added: "Australian canola growers should be very cautious in their approach to the adoption of GM Canola and we need to thoroughly examine the cost of patented seed, the claims of increased yields, reduction in herbicides and gross margins before rushing into this irreversible technology."

The GM issue has received more attention recently after news of the proposed commercial release of GM Canola by biotech giants Monsanto and Aventis in 2003.

McFarlane explained the tour has been organised to raise awareness of the economic, agronomic and environmental impacts of GM crops on conventional seed crops: "We know that in the US and Canada different farmers groups are now lobbying their governments for a moratorium on the release of further GM seed.  Australia can learn from the experiences of other nations and decide who really benefits from GM crops."