Genetically modified seed prices are rocketing and, with further increases for 2010, growers are starting to question the value of GM crops, according to the Organic Centre USA.

Charles Benbrook, chief scientist at The Organic Centre said GM seed prices had risen so sharply they were starting to rival fertilisers and agrochemicals as the most expensive crop input.

Farmers purchasing Monsanto’s Roundup Ready 2 Soyabeans in 2010 would have to pay 42% more than they paid for the 2009 product, said Dr Benbrook, who added that seed prices were now three times the historic norm.

Maize growers were facing similar price hikes, fuelled partly by seed companies introducing multiple traits into their varieties, he told a Soil Association conference in London on 3 December.

“The more traits they include, the more they can justify charging,” said Dr Benbrook. For example, Monsanto’s SmartStax maize, which is the first GM variety to include eight individual genes for herbicide tolerance and insect-protection, will be over twice the price of conventional seed when it is launched in 2010, he said. “For farmers to accept this increase it will have to perform very well indeed.

“The basic issue boils down to whether the high and rising prices of GM seeds are justified,” said Dr Benbrook. “This has to be through increased yields, lower pest management costs, or a combination of both.”

Unsurprisingly, these increases also had a striking effect on farm incomes. “Farmers planting RR2 Soyabeans in 2010 will commit a projected 22% of gross income per acre to seed purchase,” said Dr Benbrook. “This is a substantial increase from last year’s 16.4%.”

Relatively high crop values were supporting this inflated seed price, he said. “But as prices drop we will start to see problems.”

Growers who were tempted to move back to conventional seed could find it difficult to get hold of, he noted. “There is a lack of non-GM seed in the USA and farmers are starting to get worried.”