Public Release: 

Danforth Center Collaborative Research Program receives funding to improve crop yield in Africa

Project aims to develop virus resistant cassava to help farmers provide food for their families

Donald Danforth Plant Science Center


IMAGE: A photo of severely infected cassava. view more

Credit: Donald Danforth, Plant Science Center

ST. LOUIS, MO September 6, 2011-- The Donald Danforth Plant Science Center announced today that it has received additional funding totaling $11.9 million for the Virus Resistant Cassava for Africa (VIRCA) project to advance its work to improve the health and wellbeing of farmers, their families, and other consumers of cassava living in Sub Saharan Africa.

Funds will be used to support Phase II of the humanitarian effort to develop and deliver farmer-preferred cassava varieties enhanced to resist serious plant virus diseases that are greatly reducing crop yield and increasing the threat of poverty and famine.

The additional funding came from the Bill & Melinda Gates Foundation ($5.6 million), The Monsanto Fund ($5.4 million) and the Howard Buffett Foundation ($860,000). VIRCA is also supported by USAID from the American people ($2.5 million).

Two products will be developed in VIRCA-II. The first product will incorporate siRNA-based resistance to CBSD in the popular cultivar TME204, which has natural resistance to CMD and is favored by farmers in Uganda and the Lake Victoria region. "Delivery of CBSD resistant TME204 is the fastest route to address the CBSD epidemic" said Dr. Anton Bua, the Ugandan Cassava Research Team Leader in charge of field trials and communication for the project in East Africa. A second product will be developed in the highly popular, traditional Ebwanateraka cultivar in which virus sequences will be stacked to impart resistance to both CBSD and CMD. Known as the "Queen" of cassava for its taste and texture as well as its flexibility in harvesting time, Ebwanateraka has been virtually wiped out in the Uganda region due to the two viral diseases.

VIRCA-II is a collaboration between researchers at the Donald Danforth Plant Science Center in St Louis, MO, the NaCRRI, and the Kenya Agricultural Research Institute (KARI). The team will build on achievements made in VIRCA-I, during which gene silencing demonstrated success in controlling both diseases in transgenic cassava plants. Control of CMD associated with several-fold improvement in storage root yields was recently demonstrated in early field trials in Uganda.

"We are grateful for the support of our many partners for this important project. I have witnessed the devastation caused by CMD and CBSD, wiping out entire harvests, leaving many people on the verge of starvation. Our team is confident that the cassava we develop will improve the lives of millions of people allowing them to not only grow adequate food, but also to increase productivity so they might have enough money left over to educate their children and afford good medical care for malaria and other diseases they face," said Dr. Claude Fauquet, principal investigator and director of ILTAB at The Donald Danforth Plant Science Center, who serves as the lead investigator.

Cassava is one of the most important staple food crops for more than 200 million sub-Saharan Africans who derive 25 percent of their daily calorie intake from the starchy tuberous roots. In the East African countries of Uganda, Kenya, Tanzania, Mozambique, Rwanda, Burundi and Malawi, approximately 130 million people depend on the crop and produce nearly 30 metric tons of cassava annually. Cassava also contributes more than any other single crop to household income, with 63 percent of households selling cassava products.

Despite its natural drought tolerance and ability to grow well on marginal lands, cassava is susceptible to various pathogens. At least one third of the continental harvest is lost each year to Cassava Mosaic Disease (CMD) alone. Cassava Brown Streak Disease (CBSD), another viral cassava disease, is considered to be among the most dangerous plant diseases in the world for the threat it poses to food and economic security throughout Africa. In the Lake Victoria area in East Africa, more than seven million people are at risk of famine each year because of CBSD threats. The enormous urgency posed by these viruses demands that appropriate tools be applied to solve the problem.

"In Uganda, we eat cassava two or three times per day. Restoring and improving cassava productivity will be key for the improving the economic progress of the country and the region," said Dr. Titus Alicai, project lead, National Crop Resources Research Institute (NaCRRI).

In East Africa CBSD is considered a more immediate threat to cassava production than CMD because of the significant increase in geographical distribution in recent years and the dramatic effect this virus has on both yield and quality of cassava storage roots. CBSD symptoms are more subtle than CMD and may be hard to detect on leaves and stems, while causing severe necrosis in the edible storage roots and to the stems that are used to produce the next crop. Root necrosis, which can remain unnoticed until harvest, has a substantial impact on families that are dependent on the crop. Furthermore, stem cuttings produced from infected plants grow poorly or not at all, increasing chances that farmers will abandon the cultivation of cassava in severely affected regions, such as around Lake Victoria.

The enhanced cassava cultivars created by the VIRCA project will be readily available to farmers in the same way traditional cassava is being offered today and will have no royalty fees. This means farmers will be able to freely multiply, save and share their planting materials.


About Cassava

Cassava is a staple crop for more than 250 million sub-Saharan Africans. It grows productively in poor soils with little rainfall. Roots are consumed freshly boiled, or processed into a wide variety of granules, pastes and flours. Additionally, tubers can be left in the ground for up to three years. If drought or disease kills off other crops, farmer's families can still fend off starvation by eating cassava.

About The Donald Danforth Plant Science Center

Founded in 1998, the Donald Danforth Plant Science Center is a not-for-profit research institute with a mission to improve the human condition through plant science. Research at the Danforth Center will feed the hungry and improve human health, preserve and renew the environment, and enhance the St. Louis region and Missouri as a world center for plant science. The Danforth Center's work is funded through competitive grants and contract revenue from many sources, including the National Institutes of Health, U.S. Department of Energy, National Science Foundation, U.S. Department of Agriculture, U.S. Agency for International Development, the Howard Buffett Foundation, the Monsanto Fund and the Bill & Melinda Gates Foundation. For more information please visit, featuring interactive information on the Center's scientists, news and research. Follow us on Twitter at @DanforthCenter.

About The National Crop Resources Research Institute

The National Crops Resources Research Institute (NaCRRI), Namulonge is one of six public National Agricultural Research Institutes under the national Agricultural Research Organization (NARO) established by the Parliament of Uganda (National Agricultural Research Act, 2005). Originally established in 1949 as the Empire Cotton Research Station, NaCRRI was handed to the Uganda Government in 1972, and has since evolved into its present mandate to conduct research on all crops of strategic importance to the country. NaCRRI's mission is to develop and disseminate appropriate productivity-enhancing crop technologies, methods and knowledge while conserving the environment and crop genetic resources. To fulfill its mandate, NaCRRI undertakes demand-driven basic, applied, strategic, participatory and adaptive research on cassava, bananas, beans, maize, rice, sweet potato, coffee, cocoa, tea, oil palm and a broad range of horticultural crops. Core research areas are in crop breeding, genetics, agronomy, crop diseases, crop pests, modern biotechnology, on-farm trials, confined field trials, socio-economic and livelihood studies. The National Cassava Programme based at NaCRRI is globally recognized as a leader in cassava research in Africa. As a result, it was recently elevated with a regional mandate to serve as the Cassava Regional Center of Excellence. In undertaking its research, NaCRRI collaborates with several institutions at national, regional and international levels. Key partners include national research institutions in Eastern Africa, CG Centers (IITA, CIP, CIMMYT, CIAT, IRRI), advanced institutions (Danforth Plant Science Center, NRI, BeCA, FERA), local and foreign universities. The Government of Uganda, local, regional and overseas donors provide the funding for activities at NaCRRI.

About The Kenya Agricultural Research Institute

KARI was established under the Science and Technology Act of 1979 and is the premier national agricultural research institution contributing to the agricultural sector through generation of technologies, new knowledge and innovations and serving as a vehicle for economic development in Kenya. KARI contributes to sustainable improvements in the livelihoods of Kenyan citizens by increasing agricultural productivity, post-harvest value of agricultural and livestock products, and conserving the environment. In pursuit of this mission, KARI proactively seeks to acquire and contribute knowledge and creative solutions that are participatory and client-oriented, holistic, gender-sensitive and affordable to its stakeholders.

KARI places a high value on biotechnology and knows its potential to improve Kenyan agriculture. In designing its crop biotechnology program, KARI has sought to employ biotechnology first to complement the Institute's traditional methods of doing crop and livestock improvement and secondly as a strategy for generating entirely new products. Collaborative technology development and transfer projects have proved especially effective in strengthening Kenya's genetic engineering capabilities. The KARI Biotechnology Center is one of the very few African institutions with capacity and experience in the genetic transformation of crops. KARI was the first institution in Africa, outside of the Republic of South Africa, to conduct a confined field trial of a genetically-modified crop.

VIRCA II images

Video: Dr. Claude Fauquet, Principal Investigator

Danforth Plant Science Center Cassava Fact Sheet

VIRCA-II Timeline

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