Root & Tuber systems
Africa's main staple foods, roots and tubers such as cassava, yam, cocoyam, and taro, face many threats. They increasingly experience attacks from pests, weeds, disease, drought, flooding, and soil toxicity, threatening the livelihoods of more than 240 million people.
Sub-Saharan Africa produces 51%, 97%, and 77% of the total world production of cassava, yam, and cocoyam, respectively. These crops are mainly produced by subsistence farmers using traditional, often labor-intensive farming practices, and provide opportunities for generating income and improving food security. They also enhance and diversify the rural economy, alleviate poverty, and generate livelihoods for women and medium- to large-scale commercial farmers in many parts of SSA.
R4D goals
We have the global mandate to conduct research on yam and the sub-Saharan Africa mandate for cassava. Our aim is to double the productivity of the root and tuber crop subsector in the major root crop-producing countries in SSA by 2018 through our research-for-development activities.
We work with partners including international, regional, and national organizations, nongovernmental organizations, universities, the private sector, advance research institutes, and other stakeholders to reduce pre- and postharvest losses, increase productivity, and improve processing technologies, marketing, and profitability.
R4D outputs
Our program focuses on germplasm enhancement and development, production and postharvest technologies, integrated pest management, product and market development, and capacity building for R4D partners. Some examples:
We increased the productivity of root and tuber crops using conventional and new or molecular approaches. For example, we are developing improved yam varieties resistant to anthracnose disease and with better nutritional and quality traits for Africa and elsewhere. We bred over 400 cassava varieties with resistance to prevalent diseases and pests in a wide range of agroecologies and cropping systems. These new varieties have raised productivity in many African locations by 50-100%, and reflect an expanded future role for cassava in food, feed, and industrial applications.
Pest- and disease-resistant varieties have been developed including resistance to cassava green mite, cassava mealybug; mosaic disease and bacterial blight. Work on biofortification resulted in cassava varieties that have 14 times more protein than conventional varieties and varieties with higher beta-carotene, iron, and zinc.
Cassava has been transformed from a low-value crop to a cash crop through training in rapid propagation, participatory germplasm evaluation, development of processing and postharvest technologies, product diversification and improvement, and improved marketing. With partners, we developed small machines to add value, remove drudgery in production and processing, and turn roots and tubers into income-generating crops. For yams, techniques for rapid propagation using minisetts, vine cuttings, and tissue culture were developed and promoted in collaboration with partners.
We promote, through our R4D partners, farmer-to-farmer transfer of improved varieties and train growers and extension workers on appropriate cultural techniques and field management of new and disease-resistant varieties.
R4D outcomes
Our partners have distributed, among others, 40 new cassava mosaic disease-resistant varieties in Nigeria (West Africa), 36 varieties in Tanzania (East Africa), 30 varieties in the Democratic Republic of Congo; and 14 varieties in Malawi (Southern Africa). Twenty-nine other African countries now also plant improved and high-yielding varieties from national partners and IITA.
Integrated pest management work on cassava resulted in an estimated savings for African countries of US$8-20 billion for cassava mealybug since 1981 and $2 billion on cassava green mite since 1983.
Since 2001, a national partner in Nigeria has released seven IITA-derived varieties of white yam with high yields, disease resistance, and good tuber quality. Three anthracnose-resistant water yam varieties that yield about double the popular traditional cultivars are in the pipeline. A national partner in Ghana also released one new variety of white yam from germplasm provided by IITA.
Since 2004, we helped raise the income of small- to medium-scale farmers and enterprises with, for example, the establishment of 451 cassava enterprises, 30 small-scale equipment production plants in seven states, and a network of cassava equipment fabricators across Nigeria, benefiting more than 2,000 people in project areas and assisting women and vulnerable groups, and training about 250,000 farmers on farm management and rapid multiplication techniques for roots and tubers.
We introduced 22 technologies for producing and processing various cassava products, creating, for instance, 6,000 jobs and generating a total gross income of US$50 million for beneficiaries in Nigeria alone.
In collaboration with national partners, we promoted cassava as food, cash crop, and feed to farmers in Malawi, Mozambique, Tanzania, and Zimbabwe.
The national programs and NGOs provide training to farmers on cassava seed systems, production technologies, processing, production of clean planting material, and quality control of products especially flour and starch.
Through this program, we provide millions of small-scale farmers with the tools, technologies, and solutions that could help transform roots and tubers into food security crops, foreign exchange earners, and vehicles for economic development.
Projects
Root and Tuber systems - MTP Poster Root and tuber crops such as cassava, yams, and cocoyams are major staples, subject to pre- and post-harvest losses from pests and diseases.
Root and Tubers Systems fact sheet Brief description of Root and Tuber Systems program.
