{"id":13270,"date":"2026-06-20T12:26:52","date_gmt":"2026-06-20T12:26:52","guid":{"rendered":"https:\/\/dev.iita.org\/news-item\/project-brings-ray-of-hope-to-fight-against-cassava-viruses-in-africa\/"},"modified":"2026-06-29T21:39:44","modified_gmt":"2026-06-29T21:39:44","slug":"project-brings-ray-of-hope-to-fight-against-cassava-viruses-in-africa","status":"publish","type":"news-item","link":"https:\/\/iita.org\/fr\/news-item\/project-brings-ray-of-hope-to-fight-against-cassava-viruses-in-africa\/","title":{"rendered":"Project brings ray of hope to fight against cassava viruses in Africa"},"content":{"rendered":"The 5CP project has come to an end but it has made significant progress in fast-tracking the development of cassava varieties with dual resistance to two viral diseases.<\/em>\n\nIn 2012, five countries came together and shared their five best cassava varieties. The main criteria was how well they were able to resist the two viral diseases, Cassava mosaic disease (CMD<\/a>) and Cassava brown streak disease (CBSD<\/a>), affecting cassava production in Eastern and parts of Southern and Central Africa. These varieties were first cleaned of viruses before they were sent to the countries. Each country received 25 varieties to test for adaptation and performance in their local environments.\n\n
\"Picture<\/a>
Edward Kanju speaking at 5CP final meeting<\/figcaption><\/figure>\n\nFive years later, each of the five countries has identified their top four to five best varieties that will be integrated into their national breeding programs to generate more breeding populations, and further testing on-farm for acceptability and possible release as new, dual-resistant varieties.\n\nThe sharing and testing of the 25 best varieties pooled from the five countries\u2015Kenya, Malawi, Mozambique, Tanzania, and Zambia\u2015was one of the main activities of the New Cassava Varieties and Clean Seeds to combat CMD and CBSD project (5CP in short). The project was funded by the Fondation Bill & Melinda Gates<\/a>.\n\nThe activity aimed at fast tracking efforts to provide farmers with improved high-yielding and dual-resistant cassava varieties, and in turn revive the crop\u2019s production and contribute to improving income and food security of the target countries.\n\nThe project was led by IITA, working in collaboration with the national cassava breeding programs of the five countries. It started in June 2012 and came to an end on 31 March 2017.\n

Threat to cassava production<\/strong><\/h3>\nCBSD and CMD together cause production losses worth more than US$1 billion every year and are a threat to food and income security for over 30 million farmers growing cassava in East and Central Africa.\n\n\u201cAfrica loses more than a third of its potential cassava harvest to pests and diseases. The most important of these are CBSD and CMD. A severe form of CMD which causes curling of the leaves and drastically reduces yield started spreading in sub-Saharan Africa in the late 1980s and early 1990s,\u201d said Edward Kanju, IITA cassava breeder and 5CP Coordinator.\n\n\u201cIn the early 2000s, CBSD which causes a dry rot and was previously confined to low coastal areas, started spreading rapidly and nearly all the newly deployed varieties with resistance to CMD were susceptible. Countries had no varieties resistant to this new disease creating the need for the five hard-hit countries to join forces to find a quick solution,\u201d Kanju said.\n

Sharing of virus-free planting material<\/strong><\/h3>\nEach country selected and sent its top five improved varieties and one local check\u2015a local variety that is highly susceptible to the two diseases for comparison\u2015to the Natural Resources Institute (NRI, UK) and to Kenya Plant Health Inspectorate Services (KEPHIS) for virus cleaning. This was to avoid the spread of new strains of viruses to new places in the target countries.\n\nThe clean material was then forwarded to the Genetic Technologies International Ltd. (GTIL), a private tissue culture company in Nairobi, Kenya, where it was multiplied and sent to all the five countries as tissue culture plantlets. Researchers first hardened and acclimatized the plantlets before planting them in research fields in areas with high disease pressure. This was to compare their performances against the local susceptible varieties being grown by the farmers and the identified local checks.\n

A pilot clean cassava seed system<\/strong><\/h3>\nIn Tanzania, the project had another objective\u2015to develop a pilot system to deliver clean seeds of improved varieties to farmers from the research system. Under this objective, researchers from IITA, the national agriculture research system, and the Tanzania Official Seed Certification Institute (TOSCI) worked together to develop st andards for clean cassava planting material and virus testing methods.\n\nThe project also established four sites with very low disease pressure in all the main cassava-growing areas for multiplying high-quality, clean seed areas targeting various agroecologies.\n\n\u201cIn these four sites, we have so far produced 4 million cuttings. In the future, we hope to start the process of commercialization so the national root crops research system can sell this top quality planting material of high-yielding, disease-resistant varieties to private companies to multiply and deliver to farmers in large quantities. Ultimately we hope this will have a positive impact on boosting cassava production in Tanzania,\u201d said James Legg, Virologist, IITA-Tanzania.\n\nThe seed certification guidelines for cassava developed by the project were incorporated into the Seed Act of Tanzania in January 2017.\n\n
\"Picture<\/a>
A clean seed site in Tanzania<\/figcaption><\/figure>\n\n\u201cOne of the highlights of this initiative is that, working with various partners in Tanzania, we were able develop guidelines on how to produce the highest quality of cassava planting material. These guidelines were recently enacted into law. We are really excited about this,\u201d James Legg enthused.\n\nThe project trained more than 50 TOSCI seed inspectors on certification of vegetatively propagated cassava seeds and equipped the institution with essential equipment for testing viruses in cassava planting material.\n

Project successes<\/strong><\/h3>\n