The forum coincides with a State Government decision to lift a moratorium on GM canola at the end of February.

The GM forum's purpose is to educate consumers and producers about GM crops.

Canadian canola grower Percy Schmeiser will speak at the forum.

The University of Melbourne faculty of land and food resources dean Professor Richard Roush called the Mail-Times to warn Wimmera growers about Mr Schmeiser's credibility.

In 2001 Mr Schmeiser faced a Canadian Federal Court law suit over GM canola contamination.

Mr Schmeiser was charged with having grown Monsanto GM canola on his property without permission from Monsanto or payment of fees.

He claimed GM seed blew onto his property or his crop was contaminated from a neighbouring property.

The court found Mr Schmeiser grew a GM crop from seed saved from a previous year's crop.

"When you see him do a presentation, he is extremely convincing," Prof Roush said.

Organiser Jane Seymour said Prof Roush was trying to `hijack' the GM forum.

She encouraged Wimmera farmers to come to the forum to hear a different side of the GM debate.

"Farmers surely want to hear about the experience of what's happening in Canada," Ms Seymour said.

"We think this is really important; growers have to make up their own mind."

Ms Seymour defended Mr Schmeiser's credibility.

"He's won awards for standing up for the rights of farmers," she said.

"His property was polluted with Monsanto pollen and then he was sued by Monsanto.

"We're risking the Australian market. Because this market is clean and green, people are buying from Australia."

Ms Seymour said other speakers included Adelaide epidemiologist Dr Judy Carman and Japanese consumer co-operative representative Michiyo Koketsu.

Prof Roush said he had questioned Mr Schmeiser at a conference in California.

"I asked him why should we believe him over four Canadian judges," Prof Roush said.

"He said judges got things wrong all the time."

Prof Roush said his advice for Wimmera farmers was to listen to Mr Schmeiser with scepticism.

• The Horsham GM forum is on tomorrow at Wesley Performing Arts Centre from 1pm.

• Biotechnology Australia will hold a GM forum on March 5 in Horsham Town Hall.