AI tool for diagnosing potato diseases

Because potato growers need to identify and manage diseases in their fields, the AI-powered mobile app PlantVillage Nuru has been expanded to include them also.

More than two million farmers in East Africa who depend on potatoes will be able to point their smartphones at a plant and receive an instant disease diagnosis through the PlantVillage Nuru app.

Initially, the app was designed to be twice as good as extension workers in East Africa in diagnosing cassava diseases and has been a major help to cassava farmers.

“We’ve come a long way with disease detection and the rapid dissemination of management advice since the Irish Potato Famine ravaged my home country,” said David Hughes, Ph.D., Department of Entomology, PennState College of Agricultural Sciences. “The Famine kickstarted the field of plant pathology and helped formalize agricultural extension services. But the benefits of such knowledge still don’t reach millions of low-income farmers in Africa. AI can be that personal extension officer working for low-income farmers in Africa.”

From Cassava to Potatoes

With support from the CGIAR Research Program on Roots, Tubers, and Bananas (RTB) and the CGIAR Platform for Big Data in Agriculture, PlantVillage Nuru has been expanded to include potato late blight (Phytophthora infestans) and early blight (Alternaria solani).

The same fungus which decimated the Irish potato crop during the Famine continues to wreak havoc in Africa. In Uganda, for example, late blight can destroy up to 60–100% of the potato crop.

“We collected over 8,000 images of healthy and diseased potato leaves,” said Pete McCloskey, lead AI engineer at PlantVillage who worked closely with the International Potato Center (CIP). “Each leaf was then precisely annotated in order to train a neural network that runs off-line, in real-time on the phone, to localize and recognize the symptoms of potato early blight and late blight.”

Mobile phone usage is high amongst farmers in African countries such as Kenya but not all farmers have an Android smartphone. “Through our CGIAR INSPIRE grant we are providing phones to potato farmers in Kenya to replicate the success we had with cassava,” said David.

An innovative approach is not just relying on smartphones but also sending SMS messages to farmers based on the reports being received by lead farmers with phones. Currently, PlantVillage is reaching almost 500,000 farmers via SMS in Kenya with iShamba.

Pioneers in Diagnostic Mobile Phone Apps

David Hughes, together with James Legg a plant virologist with the International Institute of Tropical Agriculture (IITA) and Jan Kreuze, Leader of the Crop and Systems Science Division at CIP, pioneered the diagnostic mobile phone app which can serve as a digital assistant to help farmers identify diseases in their fields without an Internet connection and receive SMS alerts.

“We named the app ‘Nuru,’ which means ‘light’ in Swahili,” said David. “Very simply, farmers are in the dark without knowledge from experts and Nuru is the light in that darkness.”

The app is linked to Penn State’s online PlantVillage platform, which allows farmers to receive advice from experts at government agencies, universities, and research organizations in local languages. The service is currently available in Swahili, French, Twi, Hindi, and English.

Nuru was initially launched in 2018 to diagnose cassava diseases in Africa but has expanded to insect pests like fall armyworms and locusts with UN FAO.