Image copyright ROTHAMSTED RESEARCH Image caption In greenhouse tests, the new wheat has shown increased yields of between 20-40%

The planting of a new experimental crop of genetically modified (GM) wheat will take place this spring after the UK government gave the final go ahead.

The GM wheat has been engineered to use sunlight more efficiently and has boosted greenhouse yields by up to 40%.

Researchers in Hertfordshire now want to see if they can replicate these gains in the field.

Critics say that boosting wheat yields is not an answer to global food shortages.

Against the grain

Several GM trials of crops have taken place in the UK over the past 20 years, often attracting protesters who have attempted to destroy the plants.

Even when trials managed to avoid disruption, they have not always been scientifically successful.

This latest effort aims to see if the spectacular gains in productivity of 20-40% in GM wheat grown in the greenhouse can be reproduced in the open air.

Last Autumn, the scientists at Rothamsted Research submitted an application to the Department of the Environment, Food and Rural Affairs (Defra) seeking permission to carry out small field trials at a secure site near Harpenden between 2017 and 2019.

After an independent risk assessment and a public consultation, that permission has now been granted.

The researchers say they want to test newly developed wheat plants that have been modified to carry a gene from a wild relative called stiff brome.

The Rothamsted team, which is working in collaboration with researchers from the University of Essex and Lancaster University, believes this enables the modified wheat to carry out photosynthesis more efficiently, converting more sunlight and CO2 into grain.

Image copyright ROTHAMSTED RESEARCH Image caption Attempts to improve wheat with GM technology have not yet proved successful

"It makes the plant bigger in the greenhouse, it makes the leaves grow bigger, and that's because you have more of this photosynthesis going on," Dr Malcolm Hawkesford from Rothamsted told BBC News.

"Once you start to produce grain all of that CO2 fixation starts to get targeted into the production of more grain. You end with bigger plants and more grain."

With a rapidly growing global population, food production will need to increase by 70% by 2050 to meet the demand, say researchers.

The problem for wheat is that yields have reached a plateau in recent years and the scientists involved in this new trial say they have gone as far as they can in boosting growth via conventional means.

However, replicating the gains made under glass will not be easy.

"At the moment with traditional methods if you get one percent you are pretty happy," said Dr Hawkesford.

"Anything more than a few percent would be super yielding. I would be happy if we could get 5-10; anything more than that would be absolutely massive."

Feeding the world

But the planned planting is not without its critics.

Around 30 green organisations lodged objections to the plan, pointing to concerns about the potential for the GM wheat to escape into the wild, as has repeatedly happened in the US. Campaigners say they are "disappointed" that the trial is now going ahead.

"People aren't starving because photosynthesis isn't efficient enough; people are starving because they are poor," said Liz O'Neill from GM Freeze.

"Techno-fixes like GM wheat suck up public funding that could make a real difference if it was spent on systemic solutions like waste reduction and poverty eradication. Then we could all enjoy food that is produced responsibly, fairly and sustainably."

But supporters of the technology point out that if the GM wheat boosts yields it could allow farmers to grow greater amounts of the crop with fewer inputs such as nitrogen, decreasing emissions of CO2 as well.

Another concern is that the go-ahead for the new trial signals a different approach to GM as the UK faces up to Brexit. In the House of Commons last autumn, farming minister George Eustice indicated that the government was open to re-examining the position after the UK leaves the EU.

"As part of the preparations for EU exit, the government is considering possible future arrangements for the regulation of genetically modified organisms," he said in a written statement.

"The government's general view remains that policy and regulation in this area should be science-based and proportionate."

Both supporters and critics say the new trial does not signal a change in position.

"I don't believe it will make a huge difference to us," said Dr Hawkesford.

"This whole project was planned prior to Brexit. I honestly don't know if it will influence future trials, but at the moment the British government has its policy, we stick to the rules, and I wouldn't say there's any impact I would definitely see about Brexit."

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