The gap between non-genetically modified and genetically modified canola prices is $50 to $58 a tonne, yet growers say they would still take a lesser price if agronomy or herbicide choice worked in their favour.

Melbourne prices show non-GM canola at $790 a tonne against GM at $735, Adelaide at $723 compared to $673 a tonne, and Oaklands in southern NSW at $748 versus $690 a tonne.

This time last year the inland premium at Oaklands sat at $15 a tonne while Melbourne was $60 and Adelaide $33. At harvest in mid December, the widest difference between GM and non-GM sat at the ports, with Adelaide paying $100 a tonne more for non-GM and Melbourne $85 more.

GrainGrowers South Australia chief executive Brad Perry said while there was a price gap, the decision ultimately came down to what suited rotations or chemical choices better. Mr Perry said in talking to growers, canola was still very much part of the mix for this winter’s cropping rotation but they were looking carefully at inputs.

“Canola is nitrogen hungry and fertiliser is a challenge,” he said.

“Access to some chemicals has been tight, and there’s no doubt that GM canola can help in giving more options for chemical usage.”

He said the price differential at the port or silo for GM or non-GM canola continued to be quite small.

GM canola grown in Australia was bred to tolerate Group 9 herbicides such as glyphosate, allowing growers to target some grass and broadleaf weeds.

Southern NSW farmer and agronomist Don Kirkpatrick from Mangoplah said canola remained a key broadleaf rotational break for the major wheat-growing systems throughout the Riverina.

He said it was a well-established fact that the “big money” had always been in growing successful wheat crops; to do that, rotations and subsequent disease breaks had to be spot on.

However, he said canola was now also holding its own in a gross margin sense if farmers were able to get a combination of strong prices and good yields.

“The big money has always been in wheat, but canola fits the rotation and breaks disease cycles,” he said.

“People use GM canola to target grass weeds, because GM offers more options for herbicide usage and can overall keep the system profitable.”

In terms of the season Mr Kirkpatrick said early planted canola crops in the region were looking excellent.

“We are at the full ground cover stage after kind conditions and good rain in May,” he said.

“April was tough, with little rain, but conditions remained mild.”