A field trial of wheat genetically modified to repel aphids has failed, but scientists believe the process could be used to reduce the use of insecticides in other crops.
Scientists at Hertfordshire’s Rothamsted Research said they were ‘disappointed’ the trial - one of only three testing GM in the UK - did not have the same impact on aphids in the field as was initially seen in laboratory experiments.
Anti-GM campaigners branded the trial a ’waste’ of public money.
The £2.7m experiment (including site security) saw cadenza wheat genetically engineered to produce an aphid alarm pheromone which is a naturally occurring odour that that not only repels aphids but also attracts their natural enemies, such as parasitic wasps.
Although the GM wheat did not repel aphids in the field, scientists said the five-year project had brought some notable successes, including proof the plant could produce the pheromone in significant quantities without major unexpected changes seen in the appearance or performance of the new wheat plants, which looked and yielded as normal.
Prof Huw Jones, senior molecular biologist at Rothamsted Research with oversight for the genetic changes in the plants said: “The genetic engineering component worked very well and GM wheat plants performed as hoped during cultivation. It would have been a fantastic outcome if the experiment had given positive results in the field too but this was not the case and for a first attempt, this was not entirely unexpected.”
John Pickett, scientific leader of chemical Eecology at Rothamsted, said there had also been a shift in public ‘acceptance’ of the trial.
Security around the Harpenden site, which cost three times more than the scientific experiment, was stepped up in 2012 when campaigners threatened to rip up the GM crop.
Prof Pickett said the process of introducing natural enemies could also be applied to oilseed rape, where aphids transmit turnip yellow virus.
“We would see this as the heralding of a process to control insects without necessarily using a spray on, broad-spectrum eradicant or toxicant insecticide, so we see this as the beginning of an alternative approach to that,” he added.
Soil Association policy director Peter Melchett said other problems faced by farmers including the emergence of weeds such as blackgrass, increasingly resistant to weed killing chemicals, deserved priority for scarce research funding.
He said: “As many people said when the trial was first announced, aphids are not a significant problem on wheat crops in the UK, which is confirmed by the fact that organic farmers, using no insecticides, do not have problem with aphids attacking their wheat crops.”
Lincolnshire arable farmer and anti-GM campaigner Peter Lundgren said the failure of the trial ‘only reinforces that the problems we farmers face are too complex for simplistic GM solutions’.
He added: “The money, time and expertise would have been better invested in promoting Integrated Pest Management, companion cropping, conventionally bred plant tolerance and novel chemistry to give growers an effective and financially viable range of options to control pests and the diseases they carry.”