Rothamsted Research has been granted permission by Defra to extend its field trials of genetically modified wheat to include additional autumn-sown cadenza wheat.

Rothamsted scientists sought permission for the autumn trial in March this year, arguing they needed to study "wheat planted at a different time and under different weather conditions with different aphid populations."

Defra's independent Advisory Committee on Releases to the Environment (ACRE) assessed the request and held a 60-day public consultation on the issue. ACRE said it is satisfied that all scientific issues raised by the public with respect to this application have been addressed.

Rothamsted's spring trial of GM wheat, the UK's first open air trial for a number of years, caused huge controversy, culminating in a debate on Newnight and a 'day of protest' by anti-GM activists at the Institute. The cadenza wheat being used in the trials has been engineered to emit an 'odour' which repels aphids and attracts their natural enemies, including ladybirds and wasps.   

Announcing Defra's approval of the autumn trial on Thursday, Rothamsted said "the extension of the experiment will further increase the relevance to UK farmers and those in other temperate climates by covering a greater range environmental variability.  This weather variability has been particularly evident in the UK in the past 12 months."

Research leader Professor John Picket said "With the trial up and running, it seems sensible to make this small adjustment. Autumn infestations of aphids are a real problem too, especially with the varied weather we are having. This additional data will add a lot of value to the overall investigation by testing our wheat plant under a more varied range of environmental conditions throughout the year and in accordance with the different times of the year farmer's plant their wheat."

It has also been suggested that researchers wish to plant crops at a higher density to "take account of poor germination rates experienced in the 2012 planting."

Responding to the announcement, Pete Riley of campaign group GM Freeze said he was "disappointed" by Defra's decision. He said, "There are far more important areas of research which could really use the public money being spent on this trial, such as restoring UK soils." He continued, "There is no market for GM wheat anywhere in the world at present so why spend public money on a crop on one wants?"

Mr Riley added, "Given the recent unexplained GM contamination of wheat in the US, the Government need to ensure that seed used in this trial is very tightly controlled and stored to prevent this happening here and systems are in place to prevent accidental contamination in the future. Incidents in the US have occurred following experimental releases so we need to be sure it does not happen here."