Agriculture · Social Impact
David Hughes put the expert in the phone farmers already had
David Hughes · Kenya / Tanzania (built at Penn State, USA)
When cassava disease outran the number of trained experts who could diagnose it, a Penn State professor decided the smartphone already in farmers' hands was the delivery system.
The person and the place
David Hughes is an entomology and biology professor at Penn State, working with cassava farmers in Kenya and Tanzania alongside the International Institute of Tropical Agriculture.
The problem David cared about
Cassava virus diseases develop slowly and are hard to spot, and by the time an untrained eye catches one, the crop is often already lost. Smallholder farmers face this largely on their own. Hughes described the gap plainly: they are farmers "who typically don't have access to the kind of resources, such as land-grant agricultural scientists and extension specialists, that American farmers have. But they do have smartphones in increasing numbers."
The agency moment
Hughes didn't wait for enough trained experts to exist. He looked at what farmers already carried, the smartphone, and built Nuru, a computer-vision diagnostic tool that runs fully offline on an ordinary Android phone.
What changed
In a peer-reviewed field study, the 2020 version of Nuru read a single cassava leaf correctly 65% of the time, against 40 to 58% for extension agents and 18 to 31% for farmers. The same paper is careful about the limits. Single-leaf diagnosis is unreliable, and on single leaves the app caught cassava brown streak disease only 21% of the time. Show it six leaves instead of one and accuracy climbs to 74 to 88%. Overall, the paper puts Nuru level with trained agricultural extension officers rather than ahead of them. The results have faces too: Reuters found cassava farmer Roseline Akochi, who says the app changed her harvests enough to pay school fees and build a house.
The move worth copying
Hughes didn't wait for enough experts to exist. He put the expert in the phone farmers already had, and said the goal plainly: "In the last 160 years, we've largely solved the food security problem in the United States, and now we want to be a 21st century land-grant institution." Put the expertise where the person already is, instead of waiting for enough experts to exist. If your field is short of specialists, that is the version worth pointing at.
"I used to harvest 5 bags, now I harvest 200." — Roseline Akochi, cassava farmer, to Reuters
Sources
Here is where this story came from. Go read the originals.
Curated by Good in Progress from the public record.
Sources last verified .
- Penn State News, the researcher's own university newsroom ↗
- IITA, the project partner that co-developed the tool ↗
- Frontiers in Plant Science, the team's own paper ↗
- Reuters, via NTV Kenya ↗
- Brookings Foresight Africa commentary, by the Director General of IITA, the partner that co-developed Nuru ↗
- Mongabay ↗
