The International Institute of Tropical Agriculture (IITA) has launched an initiative to empower national plant protection organisations across Africa in the fight against potato cyst nematodes (PCNs) – microscopic pests wreaking havoc on potato crops throughout the region.
By Maile Matsimela, Digital Editor of African Farming
These minute worms, which attack potato roots and stunt plant growth, have the devastating potential to destroy up to 100% of potato yields. PCN has already established a significant presence in four countries across East and Southern Africa.
Classified as a quarantine pest, PCN infects and feeds on potato roots, resulting in substantial yield losses. The pest also poses a significant threat to regional trade because of strict border phytosanitary controls, making early detection and management critical for protecting farmer livelihoods and regional potato markets.
A project funded by the World Trade Organization’s (WTO’s) Standards and Trade Development Facility and coordinated by the Food and Agriculture Organization (FAO) has been implemented to address this growing concern. Technical training, led by IITA and the International Centre of Insect Physiology and Ecology (ICEPE) through the NemAfrica laboratory, aims to equip national plant protection agencies in 12 countries with state-of-the-art diagnostic tools and management strategies. This collaborative initiative also involves the International Potato Center (CIP), the Kenya Plant Health Inspectorate Service (KEPHIS) and CABI.
Also read: Smarter pest management essential for potato sustainability
Future Of Potato Production Under Threat
Potatoes constitute an essential staple food in eastern and Southern Africa, supporting approximately 800 000 smallholder farmers across more than 800 000ha of land. The region produces nearly nine million tonnes of potatoes annually. However, the silent and deadly spread of PCN threatens the future of potato production in the area.
PCN remains largely hidden from view and is frequently overlooked or misdiagnosed as soil fertility issues, often referred to as “sick” or “tired” land. Plants affected by the pest exhibit stunted growth and yellowing, and produce smaller tubers, resulting in significant yield reductions. The project emphasises the urgent need for awareness campaigns to guide effective management strategies.
“By strengthening diagnostic capacity and fostering regional collaboration, this project is a vital step towards safeguarding potato production and trade in East and Southern Africa,” said Dr Harun Murithi, Consultant Crop Health Specialist – Disease and Pest Management at IITA. “Accurate identification of PCN will enable timely interventions, protecting farmers’ livelihoods and contributing to food security.”
The training programme focuses on the accurate assessment and diagnosis of PCN, encouraging stakeholders throughout the potato value chain – from farmers to traders and policymakers – to familiarise themselves with PCN symptoms. Additionally, the project underscores the importance of regional cooperation to prevent the further spread of the pest.
Technicians and laboratory staff receive training in sample collection, extraction and PCN identification. Essential diagnostic equipment and consumables, including a key extraction tool known as the Fenwick can and sieves, are being provided to national plant protection laboratories. The project also supports detection surveys in major potato-growing regions to map PCN presence.
The project, which covers 12 countries selected for their regional importance and trade connections, recently conducted a training workshop in Nairobi. Representatives from Kenya, Uganda, Burundi, South Sudan, Rwanda, Ethiopia, Zimbabwe, Zambia, Malawi, Mozambique, Tanzania and Lesotho gathered to develop foundational diagnostic skills for their respective national plant protection organisations.
Following this training, several countries have commenced national detection surveys with support from NemAfrica. Zimbabwe has completed sample extraction and identification, and Zambia and Malawi continue to make progress. Ethiopia has finished sample collection, with similar activities planned for Lesotho, Mozambique and Uganda.
