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When Dave Hodson walked through wheat fields in Ethiopia in 2010, it seemed as if everything had been painted yellow. A rust fungus was in the process of infecting about one-third of the country’s wheat, and winds had carried its spores far and wide, coating everything in their path. “The fields were completely yellow. You’d walk through them and your clothes were just bright yellow,” he says.

Hodson, who was then at the UN’s Food and Agriculture Organization in Rome, had flown down to Ethiopia with colleagues to investigate the epidemic. But there was little that could be done: Though the authorities had some fungicides, by the time they realized what was happening, it was too late. Ethiopia, the biggest wheat-producing nation in sub-Saharan Africa, lost between 15% and 20% of its harvest that year. “Talking with farmers—they were just losing everything,” Hodson told MIT Technology Review. “And it’s just like, ‘Well, we should have been able to do more to help you.’”

Hodson, now aprincipal scientist at the international nonprofit CIMMYT, has since been working with colleagues on a plan to stop such losses in the future. Together with Maricelis Acevedo at Cornell University’s College of Agriculture and Life Sciences, he co-leads the Wheat Disease Early Warning Advisory System, known as Wheat DEWAS, an international initiative that brings together scientists from 23 organizations around the world.

The idea is to scale up a system to track wheat diseases and forecast potential outbreaks to governments and farmers in close to real time. In doing so, they hope to protect a crop that supplies about one-fifth of the world’s calories.

The effort could not be more timely. For as long as there’s been domesticated wheat (about 8,000 years), there has been harvest-devastating rust. Breeding efforts in the mid-20th century led to rust-resistant wheat strains that boosted crop yields, and rust epidemics receded in much of the world. But now, after decades, rusts are considered a reemerging disease in Europe. That’s due partly to climate change, because warmer conditions are more conducive to infection. Vulnerable regions including South Asia and Africa are also under threat.

Wheat DEWAS officially launched in 2023 with $7.3 million from the Bill & Melinda Gates Foundation (now called the Gates Foundation) and the UK’s Foreign, Commonwealth & Development Office. But an earlier incarnation of the system averted disaster in 2021, when another epidemic threatened Ethiopia’s wheat fields. Early field surveys by a local agricultural research team had picked up a new strain of yellow rust. The weather conditions were “super optimal” for the development of rust in the field, Hodson says, but the team’s early warning system meant that action was taken in good time—the government deployed fungicides quickly, and the farmers had a bumper wheat harvest. 

Wheat DEWAS works by scaling up and coordinating efforts and technologies across continents. At the ground level is surveillance—teams of local pathologistswho survey wheat fields, inputting data on smartphones. They gather information on which wheat varieties are growing and take photos and samples. The project is now developing a couple of apps, one of which will use AI to help identify diseases by analyzing photos.

Another arm of the system, based at the John Innes Centre in the UK, focuses on diagnostics. The group there, working with researchers at CIMMYT and the Ethiopian Institute of Agricultural Research, developed MARPLE (a loose acronym for “mobile and real-time plant disease”), which Hodson describes as a mini gene sequencer about the size of a cell phone. It can test wheat samples for the rust fungus locally and provide a result within two to three days, whereas conventional diagnostics need months.

 “The beauty of it is you could pick up something new very quickly,” says Hodson. “And it’s often the new things that give the biggest problems.”

The data from the field is sent directly to a team at the Global Rust Reference Center at Aarhus University in Denmark, which combines everything into one huge database. Enabling nations and globally scattered groups to share an infrastructure is key, says Aarhus’s Jens Grønbech Hansen, who leads the data management package for Wheat DEWAS. Without collaborating and harmonizing data, he says, “technology won’t solve these problems all on its own.”

“We build up trust so that by combining the data, we can benefit from a bigger picture and see patterns we couldn’t see when it was all fragmented,” Hansen says.

Their automated system sends data to Chris Gilligan, who leads the modeling arm of Wheat DEWAS at the University of Cambridge. With his team, he works with the UK’s Met Office, using their supercomputer to model how the fungal spores at a given site might spread under specific weather conditions and what the risk is of their landing, germinating, and infecting other areas. The team drew on previous models, including work on the ash plume from the eruption of the Icelandic volcano Eyjafjallajökull, which caused havoc in Europe in 2010.

Each day, a downloadable bulletin is posted online with a seven-day forecast. Additional alerts or advisories are also sent out. Information is then disseminated from governments or national authorities to farmers. For example, in Ethiopia, immediate risks are conveyed to farmers by SMS text messaging. Crucially, if there’s likely to be a problem, the alerts offer time to respond. “You’ve got, in effect, three weeks’ grace,” says Gilligan. That is, growers may know of the risk up to a week ahead of time, enabling them to take action as the spores are landing and causing infections.

The project is currently focused on eight countries: Ethiopia, Kenya, Tanzania, and Zambia in Africa and Nepal, Pakistan, Bangladesh, and Bhutan in Asia. But the researchers hope they will get additional funding to carry the project on beyond 2026 and, ideally, to extend it in a variety of ways, including the addition of more countries. 

Gilligan says the technology may be potentially transferable to other wheat diseases, and other crops—like rice—that are also affected by weather-­dispersed pathogens.

Dagmar Hanold, a plant pathologist at the University of Adelaide who is not involved in the project, describes it as “vital work for global agriculture.”

“Cereals, including wheat, are vital staples for people and animals worldwide,” Hanold says. Although programs have been set up to breed more pathogen-­resistant crops, new pathogen strains emerge frequently. And if these combine and swap genes, she warns, they could become “even more ­aggressive.”

Shaoni Bhattacharya is a freelance writer and editor based in London.