Genetic modification can improve crop yields — but stop overselling it

Over the past two decades, many journals, including this one, have published papers describing how modifying one or a few genes can result in substantial increases in crop yields (see ‘Genes and yield’). The reported increases range from 10% to 68%, and the crops analysed include rice, maize (corn), tobacco and soya bean.

These studies have contributed important insights in molecular biology and gene discovery. But many are the results of tests conducted in greenhouses or in small-scale field trials — the latter typically involving plants grown in small plots. Few, if any, have used the experimental designs needed to evaluate crop performance in real-world environments. And hardly any findings have translated into yield increases on actual farms.

Especially in the context of climate change and a growing human population, the growth of misleading claims around yields has become a cause of concern to us. As plant breeders, quantitative geneticists, evolutionary biologists and plant biologists, many of us have worked on national projects or on crop breeding in collaboration with multinational companies.

To encourage more impactful science, we ask researchers, reviewers and journal editors to ensure that at least five criteria are met whenever claims are made about the effects of single genes or a few genes on the yield of a crop. We also urge researchers across our range of disciplines to work together much more than they currently do, and to use well-established yield-testing approaches.