A cheap paper strip now flags three crop viruses in the time it takes to boil a kettle
Field trials in two countries showed farmers could test leaf sap without a lab, with accuracy close to the clinic test they cannot afford to wait for.
The strip looks like a pharmacy pregnancy test and costs less than a cup of tea. It does not replace a laboratory. It tells a farmer whether to isolate a row today rather than next week.
Researchers designed it for cassava and maize viruses that travel on whitefly. A false negative is still possible if the leaf is sampled too young. Training, they say, is a morning, not a degree.
Aid agencies have asked for a million units. The university that holds the patent says it will license at cost in the trial countries first.
