An Australian farmer dealing with the fallout from genetically engineered crop contamination says that sort of production in previously GE-free areas is dividing rural communities.
Bob Mackley is a cropping and sheep farmer in western Victoria.
He and fellow Australian farmer Julie Newman are touring New Zealand with Green MP Steffan Browning, outlining their experiences of what happens when GE crops are introduced.
Mr Mackley says the Victorian government lifted a moratorium to allow commercial production of genetically engineered canola.
His troubles began when a neighbouring farmer cut a crop of canola genetically modified for herbicide resistance, which was then washed onto his land during a heavy rainstorm - enough seed , he reckoned, to sow several hundred hectares.
He says he was very concerned because he had made a conscious marketing decision to reject GE.
Community bonds 'weakened'
Mr Mackley says he met with the farmer and three representatives from seed company Monsanto and Monsanto basically said it was his problem.
"I've had to change my farming rotations and my herbicide usage in those paddocks in order to do everything I can to eliminate the GE canola from my place, but it's been entirely at my cost and increased effort and of course it's disrupted my normal cropping rotations."
Mr Mackley says it's weakened the community bonds in the area and although he still speaks to his neighbour they no longer discuss anything of any importance.
He says New Zealand needs to be aware that once the green light is given for GE production, there is no turning back.
"If New Zealand does go down the GE path," he says, "it is absolutely critical that the responsibility for non-GE farmers' losses must be squarely on the shoulders of the owners of the patents."