Because fungal outbreaks can completely wipe out their crops if they’re not careful, farmers do two things. One, they spray with fungicide. And two, they test the soil for fungal spores. Neither action is ideal. Fungicide is toxic, and overuse leads to resistance. And testing can take time and be expensive. While farmers are waiting for their results back from the lab, their fields can already be overrun.
That’s why two PhD students at Imperial College London are developing FungiAlert, an in-field device that changes color in the presence of certain pathogens. They believe it offers a cheaper alternative to lab-testing and a way to reduce the amount of poisonous chemicals going into the ground.
“We’re trying to address the time it normally takes for farmers, and we’re also trying to make it more reliable and accurate protection,” says Kerry O’Donnelly, who’s working on the device with her lab partner Angela de Manzanos. “It means that farmers don’t have to sample lots of their fields. They can cover a broad range with our device.”
About the size of a garden solar light, the device contains chemicals that attract spores from the soil. Once inside, the microorganisms colonize and grow, triggering a color change in the indicator. At the same time, the FungiAlert also sends out wireless signals, so farmers get an message on their phones when there’s a problem.
The product isn’t yet on the market, but O’Donnelly and De Manzanos say major companies have expressed interest. They hope to manufacture two versions: one with a wireless chip (cost: $10), and another with just the color-change mechanism ($5). There would also be different types matching likely types of pathogens in the soil.
Potentially, the device could allow farmers to spray only when they know they have a fungal outbreak, not preemptively in case they might have an issue. “We want the device to allow famers to make smarter decisions about the right types of fungicides and so reduce the threat of resistance,” O’Donnelly says. “Resistance is becoming a huge problem. Sooner or later, we’re not going to have very limited fungicides to kill these pathogens.”
The scientists plan to work full time on their idea from this October, and hope to start field trials with strawberry farmers soon. If they can cut the cost of dealing with fungi outbreaks and reduce fungicide use, they’ll be doing farmers and the rest of us a favor.