FARMERS selling genetically modified canola are facing discounts of $14-$30 a tonne for their grain. The price disparity between GM and conventional canola is up to $30 a tonne at some sites. Cargill is quoting $14-15 a tonne difference, while GrainCorp is quoting $30 a tonne difference at Lillimur in the West Wimmera for 2012-13 grain. GrainCorp’s daily prices show the top price for conventional canola is $576 a tonne delivered to Geelong, while the top price for GM canola is $535 a tonne delivered to St James, north of Benalla.