Smartphone app helps farmers control potato diseases
Pests and diseases destroy between 20 and 40 per cent of crops globally, and farmers in developing countries are especially vulnerable to that destruction because they often aren’t sure what is affecting their crops. Or they lack good advice on how to control it. Lower yields and income loss often follows and contributes to hunger or malnutrition.
Helping small-scale farmers detect and control crop pests and diseases can improve their harvests and incomes but given the diversity and intensity of pest and disease threats, this is no small task. Most sub-Saharan African (SSA) nations have a fraction of the extension agents they need to reach all their farmers, ranging from one agent per 1,000 farmers to one for every 5,000-10,000 farmers, depending on the country. To help overcome this challenge, scientists are using digital technologies to bridge the extension gap, and the recent addition of potato and sweetpotato diseases to the PlantVillage Nuru diagnostic app are important milestones in an ongoing initiative to help African farmers produce more food with the help of mobile phones.
Nuru (which means “light” in Swahili) is a free smartphone app that provides real-time diagnoses of plant diseases or pests in the field, even in areas outside mobile networks. It was developed by scientists at Penn State University and several CGIAR centers, and forms part of PlantVillage – a farmer support platform that combines artificial intelligence and satellite technology with a corps of extensionists dedicated to promoting the use of those tools. Nuru was launched in Africa in 2018 with a capacity to diagnose two cassava diseases (CMD and CBSD). It was subsequently expanded to cover fall army worm and desert locust, in collaboration with the Food and Agriculture Organization of the United Nations (FAO).
Scientists with the International Potato Center (CIP) and Penn State have collaborated on the development of artificial intelligence (AI) for Nuru to diagnose sweetpotato virus infections and potato early blight and late blight diseases. Sweetpotato virus diagnosis was added to the version of the app available on Google Play as of March 2022, whereas late and early blight diagnostics were added in late 2021. Potato and sweetpotato are increasingly important cash and food security crops in much of SSA, where they are primarily grown by smallholder farmers, who commonly suffer yield loss due to diseases.
“By providing farmers access to quick diagnosis of the most serious diseases affecting some of Africa’s most important crops, this innovation is contributing to food and nutrition security and livelihoods,” says Jan Kreuze, leader of CIP’s Crop and Systems Science Division.
About 30 types of viruses can infect sweetpotato plants – spread by whiteflies, aphids and planting material – and depending on the kind or combination of viruses, they can devastate yields. Late blight, a quick-spreading,
wind-borne disease, can destroy 60% of a potato crop or more in a few rainy weeks if left untreated, which leads farmers to use large amounts of agrochemicals to control it. For both diseases, early diagnosis is
vital for effective management. Tools to boost yields Kreuze explains that the AI that enables Nuru’s diagnostic capacity was developed with tens of thousands of photos of diseased and healthy plants and improved through repeated field evaluations. He explains that sweetpotato is especially challenging because viral infections are often asymptomatic, and the symptoms that are visible differ from one variety to the next. To enable Nuru to diagnose viral infections in plants with few or no symptoms, researchers used diagnostic tests to identify asymptomatic infected plants, in hopes of teaching Nuru’s AI to detect symptoms that even experts might not spot.
Peter McCloskey, lead engineer at PlantVillage, notes that it took five years to develop the artificial intelligence for Nuru to diagnose cassava virus diseases. A 2020 study determined that the accuracy of Nuru’s cassava disease diagnosis was about 65 percent, which was lower than crop experts but higher than extension workers. However, McCloskey says that its diagnostic capacity has been significantly improved since then. He adds that, while improving the diagnoses of disease already in the app, his team is working to expand the number of pests and diseases it covers.
Continued on www.dailytrust.com