Science can rescue farming

Empty shelves in supermarkets have reminded us that our food supply is rather more fragile than we thought. Indeed, who would have believed that in 2021 we need a cabinet minister responsible for the supply of food? Whatever the reasons for the situation, this might be a sign of the future. Ensuring food security in the long term could prove much more challenging than our short-term problems. Even amid the pandemic, it is hard to ignore the floods, wildfires and hurricanes occurring with ever-increasing ferocity. The climate emergency now feels very real and doing nothing is no longer an option.

I study plant diseases, many of which are serious threats to humankind. The rice blast fungus, my main obsession, destroys enough rice each year to feed 60 million people. We are already seeing the effects of climate change with new plant diseases moving rapidly around the world and need new disease-resistant crops to combat these threats.

Conventionally, we have created these through plant breeding. However, this is a long process, requiring skill and patience. We must act more quickly given the magnitude of the climate emergency. The predicted increase in the human population and greater urbanisation mean we will also need to grow much more food on much less land, in a way that does not damage the planet.

However, we are still struggling to find sustainable solutions to plant diseases that have plagued us for centuries. One example that is relevant to the history of the British Isles is potato late blight, which causes about $5bn (£3.6bn) in losses worldwide each year. This is the disease that caused the Irish potato famine in the 1840s from which the Irish population has yet to fully recover. The warm and humid late summers of these islands mean that late blight is a constant threat for potato farmers. Currently, we spray 15 to 20 times a year with fungicides to control the disease. These agrochemicals are not only expensive, but entirely fossil-fuel based.

It has been reported that the government is looking to relax the rules on genome editing following departure from the EU. In a consultation earlier this year, the Department for Environment, Food and Rural Affairs recently asked whether genome editing should be treated in the same way as genetic modification (GM) is regulated under EU law. With genome editing, very small and specific changes are made to a plant gene that can have a significant impact on that plant’s resilience to its environment and ability to grow with fewer inputs, such as lower nitrogen levels. We can thereby achieve the outcomes of plant breeding, which has been so successful in improving crop yields, but in a much more precise manner. Genome editing has considerable promise in accelerating plant breeding and the decision to proceed would be very welcome, but where does this leave the debate on GM crops?

Take, for instance, the situation with potato blight. Research at the Sainsbury Laboratory, led by my colleague Professor Jonathan Jones, has already discovered many resistance genes from close relatives of commercial potatoes. We know that, if introduced through genetic modification, these genes enable potatoes to detect the disease and activate natural defences. This works in the field. If British farmers could access these resistant potato varieties, it would immediately lead to a substantial reduction in the carbon footprint of agriculture.

GM therefore enables innovation in ways that cannot be achieved just through genome editing; by moving genes from one plant to another we can achieve a blight-resistant potato. The perception that genetic modification is more disruptive, and therefore less safe, than genome editing is not based in scientific evidence. These crops have been subject to more than 4,400 risk assessments by regulatory experts in 71 countries and no increased risk to humans or the environment has been revealed. They have been consumed by more than 350 million people for more than 25 years with no recorded ill-effects. Both methods offer potential solutions to different aspects of our food security problems.

These genetic technologies could be vital in achieving net-zero carbon agriculture within the critical timeframe. Yet they are only one of a set of tools that we will need – there is no single “magic bullet” solution. Many facets of our farming methods need to change, in addition to crop breeding methods. Organic farming has provided us with creative and powerful alternatives for how we grow food. By combining the benefits of ecologically sensitive organic production with innovation in crop improvement, we could develop powerful holistic solutions for sustainable agriculture. For this to happen, however, we need to focus on the shared objectives of the proponents of genetic technologies and those environmental groups who oppose these methods. Both sides want to neutralise the pressure of farming on our ecosystems by reducing chemical inputs.

We need a robust, transparent regulatory framework for genetic technologies in crop development. This is vital for public confidence in these methods, but also needs to be part of a national debate about the innovations necessary to change agriculture and to provide clear consumer benefits.

Regulations should focus on novel crop varieties being safe, healthy, nutritious and environmentally beneficial, rather than the technologies used to produce them. We have an opportunity to make British agriculture world-leading in sustainability, rather than having innovations crippled by excessively stringent regulations based on outdated knowledge and media-driven fears.

There is a real opportunity for these technologies to underpin the changes to our agricultural system that we so desperately need, and to do it relatively quickly. A good starting point would be to shift the conversation away from where we disagree to where we definitely agree – a future in which we can grow more healthy and nutritious food on less land and finally get off the chemical treadmill.

 * Professor Nick Talbot is executive director of the Sainsbury Laboratory