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Project FAQ

What is the VIRCA PLUS project?

VIRCA Plus is a research project to develop virus disease resistant and nutritionally enhanced cassava varieties that will empower African smallholder farmers and improve the health status of consumers.

Launched in 2016, VIRCA Plus builds on the success of two predecessor projects. The Virus Resistant Cassava for Africa (VIRCA) project successfully developed strong and stable resistance to Cassava Brown Streak Disease, validated over multiple cropping cycles in several locations in Kenya and Uganda. The BioCassava Plus project developed and tested cassava plants with 10 times more iron and zinc than comparable varieties, levels that would bring nutritionally significant benefits to consumers.

VIRCA Plus combines and leverages the knowledge, experience and achievements of these two earlier projects in continued work to improve cassava harvests and provide better nutrition in East and West Africa.

Why cassava?

Cassava is grown in over 30 African countries. Approximately one-third of the continent’s population relies on cassava’s starchy tuberous roots for over 50% of their daily caloric intake, making it the second most important staple food crop (after maize). It is also an important cash crop for smallholder farmers, because it grows relatively well in conditions of heat, drought and low soil fertility prevalent in many African countries. Cassava is also profitably used in the manufacturing of biofuel, beverages and processed products across Africa, providing steady markets and income for farmers.

What is the difference between VIRCA Plus cassava and other cassava varieties? Why do some plants look different in field trials?

VIRCA Plus cassava will be similar to other cassava varieties that farmers in Kenya, Nigeria and Uganda have been growing, different only in its superior ability to resist diseases and/or its enhanced nutritional quality. Researchers are using field trials to develop the best varieties. Because plants in the field trials have been produced from different combinations of parent plants, they look different from each other. Breeders grow many plants over multiple seasons to examine the height, root size and other qualities so that they can select those that will meet farmers’ needs.

When will farmers have access to VIRCA Plus cassava varieties?

Specific timelines for development of varieties, regulatory decision-making and farmer access are difficult to predict. Cassava has a relatively lengthy growing cycle, which means it takes a long time to breed new varieties. It must go through several years of development to identify, test and multiply varieties that meet farmers’ needs. Furthermore, the time it takes to complete regulatory review and decision-making can be lengthy and uncertain.

Disease resistant cassava : Years of work in the laboratory, greenhouse and field trials by VIRCA Plus partners have lead to the selection of Cassava Brown Streak Disease (CBSD) resistant Cassava Line 4046, which can protect farmers of this important crop from devastating losses. In May 2020, the Kenya Agricultural and Livestock Research Organization (KALRO) announced submission of an application to the National Biosafety Authority (NBA) for  environmental release (open field cultivation) and placing on the market of this line. Although based on a popular cassava variety, the specific line 4046 will not be made available as a stand-alone product. Breeding work is already underway under regulated Confined Field Trials (CFTs) to develop individual varieties incorporating line 4046. CBSD resistant cassava varieties will be duly registered through the national variety registration system by the Kenya Plant Health Inspectorate Service (KEPHIS). Seed multiplication and distribution will follow the normal and existing quality seed delivery systems. Read more about CBSD resistant cassava in Kenya.

Nutritionally enhanced cassava are expected to begin field evaluation in Nigeria in 2020, and follow a similar multi-year development, testing and review timeline.

Who will claim ownership of VIRCA Plus cassava? Will farmers have to pay? Will they be able to replant?

Like other crop varieties developed by national agriculture research organizations, VIRCA Plus cassava will be accessible and affordable to farmers. There will be no charge or restriction of rights from any of the technology developers: Danforth Plant Science Center or partners in the National Agricultural Research organizations in Kenya, Nigeria and Uganda. VIRCA Plus cassava will be released to breeders to develop further into new varieties. When delivered to farmers, VIRCA Plus cassava varieties may be planted, grown, consumed, sold and replanted from cuttings, as is current practice with conventional varieties.

Will VIRCA Plus cassava have the same economic value as other cassava?

With combined resistance to two devastating diseases, it is expected that VIRCA Plus cassava will have higher productivity and economic value to farmers than the current varieties which are susceptible to lower quality and yield loss from the diseases.

Nutritionally enhanced VIRCA Plus cassava may have greater economic value to farmers and consumers due to health benefits from additional iron and zinc.

Who is involved in the VIRCA Plus project? What are their roles?

In Kenya, the Kenyan Agricultural and Livestock Research Organization (KALRO) is the lead agency for all technical and field activities. The ISAAA AfriCenter in Kenya supports stakeholder outreach. The International Institute for Tropical Agriculture (IITA) in Kenya conducts research and development activities.

In Nigeria, the National Root Crops Research Institute (NRCRI) in Umudike carries out research and development activities for nutritionally-enhanced VIRCA Plus cassava. The OFAB Nigeria Chapter and National Biotechnology Development Agency (NABDA) support communications and outreach activities in the country.

In Uganda, the National Crop Resources Research Institute (NaCRRI) of the National Agricultural Research Organization (NARO) is the lead agency for all technical and field activities. The Science Foundation for Livelihoods and Development (SCIFODE) leads communication and stakeholder outreach on behalf of the project.

The Donald Danforth Plant Science Center in St. Louis, Missouri, USA coordinates the VIRCA Plus project overall, and also undertakes basic research and development activities.

Who is funding the VIRCA Plus project?

Current and past supporters of the VIRCA, Biocassava Plus and VIRCA Plus projects include: the governments of Kenya, Nigeria and Uganda, the Bill & Melinda Gates Foundation, the Howard Buffett Foundation, Bayer (formerly through Monsanto and the Monsanto Fund), and the United States Agency for International Development. Funding is in the form of cost-sharing and charitable grants that bring no financial benefits to supporters.

Disease Resistance FAQ

Which cassava diseases are you working on and why are they important?

VIRCA Plus is developing cassava that carries resistance to two viral plant diseases at once: Cassava Brown Streak Disease (CBSD), which destroys the edible roots even when rest of the plant looks healthy, and Cassava Mosaic Disease (CMD), which can stunt plants to varying degrees or kill them completely. These two diseases are often found together in the same field and can devastate entire crops. Both diseases are spread by white-flies (high populations of which cannot be controlled effectively with pesticides) and by infected cassava stem cuttings shared among farmers.

CMD has been damaging farmers’ fields across Africa for decades. Over the last 15 years, CBSD has also spread rapidly and now affects cassava production across East and Central Africa. It threatens to move into West Africa where it would have devastating effects on cassava production and food security in Nigeria, Africa’s most populous country and largest cassava producer. As a result, CBSD has been defined as one of the seven most dangerous plant diseases in the world due to its ongoing and potential impact on food and economic security.

Will VIRCA Plus virus disease resistant cassava varieties protect against all diseases?

No. VIRCA Plus disease resistant cassava is intended to protect the crop against two viral diseases—CBSD and CMD. Farmers will be encouraged to continue with other good farm management practices to provide protection against other local diseases, pests, weeds and other environmental factors that impact production.

Nutritional Enhancement FAQ

What nutritional enhancements will VIRCA Plus cassava have?

VIRCA Plus is developing cassava that has elevated levels of both iron and zinc for improved nutrition, as well as resistance to cassava virus diseases. The BioCassava Plus project (2005-2016) succeeded in developing and testing cassava plants that accumulated greater than 10 times more iron and zinc than comparable varieties, using the tools of modern biotechnology. When used in recipes for common African foods (such as gari and fufu), the enriched cassava roots could provide 40-70% of the Estimated Average Requirements of iron and zinc for vulnerable women and children.

Iron deficiency anemia compromises the immune system, stunts growth and impairs cognitive development in children, while deficiency in zinc causes increased risk of death from diarrhea, stunting and reduced cognitive development. In Nigeria alone, 75% of preschool children and 67% of pregnant women are anemic (WHO 2008) and across sub-Saharan Africa an estimated 24% of the population are at risk from zinc deficiency due to inadequate dietary intake (Prasad, 2012).

The primary source of dietary iron and zinc for rural and urban resource poor is obtained through consumption of plant foods, especially legumes, leafy vegetables and whole grain cereals. However, access to the required quantity of these foods is often seasonal and the quality is not assured. Cassava roots are an excellent, low cost source of starch year-round, but they contain a fraction of the iron and zinc required in a healthy diet. Nutritionally enhanced VIRCA Plus cassava varieties with higher levels of these minerals could help reduce the ‘hidden hunger’ of micronutrient malnutrition.

Safety FAQ

What technologies are you using and why? Is VIRCA Plus cassava genetically engineered (a ‘GMO’)?

VIRCA Plus researchers are using a range of technologies to improve cassava, including conventional plant breeding, genetic engineering (also known as genetic modification (GM) or biotechnology), molecular analysis, and genomic screening.

For example, conventional plant breeding has been successfully used to develop cassava varieties that are resistant to CMD. But plant breeders have been less successful with CBSD, thus far developing varieties that are merely tolerant to CBSD. CBSD tolerant cassava plants may still show some virus symptoms and suffer damage from the disease – and may cause the disease to spread further.

Therefore, VIRCA Plus is using genetic engineering to introduce a small component of the Cassava Brown Streak Virus into cassava to make the plants resistant to CBSD by a mechanism called RNA interference (RNAi). RNAi has been used to develop a number of disease resistant crops, most notably saving the papaya industry in Hawaii from the devastating Papaya Ringspot Virus Disease. When both cassava virus disease resistance traits are combined and bred into VIRCA Plus varieties, farmers will be able to grow cassava with specific resistance to both diseases for the first time.

Genetic engineering is also a necessary tool for VIRCA Plus nutritionally enhanced cassava, because it has not been possible to enhance the iron and zinc content of cassava storage roots through conventional plant breeding of existing varieties and breeding lines. In VIRCA Plus, genetic engineering is being used to incorporate two genes from another plant, Arabadopsis, that function to elevate iron and zinc content in cassava roots.   Breeding will also be used to incorporate this trait into high-performing cassava varieties that meet the needs of farmers and consumers.

Molecular analysis and genomic screening tools are being used in both projects to inform researchers about the presence, efficacy and safety of VIRCA Plus varieties as they are developed.

Will VIRCA Plus cassava varieties be safe for farmers to grow and consume? How will you know?

Yes. As a genetically engineered crop, VIRCA Plus cassava is being assessed for food safety and environmental impact according to national regulatory processes in VIRCA Plus partner countries – Kenya, Nigeria and Uganda. VIRCA Plus cassava will be made available to farmers and consumers in a country only if the regulatory agency concludes that all national safety requirements are met and approves it for release.

Specific results from field trials, laboratory analysis, and other studies are required to determine that biotechnology crops are as safe as conventional crops.

Once all studies are completed, a regulatory ‘dossier’ containing information about the safety of VIRCA Plus cassava will be compiled and submitted to regulatory agencies in each country for their review. VIRCA Plus cassava can be made available to farmers and consumers in a country only if the regulatory agency concludes that all national safety requirements are met and approves it for release.

What is the purpose of field trials in assessing the safety of VIRCA Plus cassava?

Field trials are being conducted in Kenya and Uganda to generate regulatory data and gather information about the safety of VIRCA Plus cassava. With review, approval and regular monitoring from national biosafety agencies, field trials of VIRCA Plus and conventional cassava plants of the same variety are grown in the same locations so that agronomic information can be collected on both for comparison. Throughout the growing season, researchers carefully note characteristics such as the height, vigor, timing of flowering, number and size of roots, and susceptibility to pests, diseases and other stresses for both VIRCA Plus and conventional cassava plants.

  • If the VIRCA Plus and conventional cassava plants show similar characteristics and qualities in field trials, it demonstrates that the plants are the same except for the intended change of resistance to cassava virus diseases.

Once all studies are completed, a regulatory ‘dossier’ containing information about the safety of VIRCA Plus cassava will be compiled and submitted to regulatory agencies in each country for their review. VIRCA Plus cassava can be made available to farmers and consumers in a country only if the regulatory agency concludes that all national safety requirements are met and approves it for release.

What do laboratory tests tell us about the safety of VIRCA Plus cassava?

The roots and leaf tissues from VIRCA Plus cassava and conventional cassava grown in field trials will also be analyzed in the laboratory as part of the safety assessment process. The levels of moisture, starch, protein, fat and key nutrients (especially iron and zinc levels of nutritionally enhanced VIRCA Plus cassava) will be measured and results compared. The levels of cyanogenic glycosides will also be analyzed; these are naturally-occurring toxic components found in all cassava plants that are removed in proper traditional food preparation processes.

  • If the analysis shows that VIRCA Plus and conventional cassava plants contain similar amounts of the same components (and intended higher levels of iron and zinc for nutritionally enhanced cassava), it demonstrates that one is as safe and as nutritious to eat as the other.

Other studies that are being used to demonstrate that VIRCA Plus cassava can be grown safely include molecular characterization, which is an analysis of the DNA that has been inserted into VIRCA Plus cassava and its stability (ability to remain unchanged) through multiple generations of the plant.

Once all studies are completed, a regulatory ‘dossier’ containing information about the safety of VIRCA Plus cassava will be compiled and submitted to regulatory agencies in each country for their review. VIRCA Plus cassava can be made available to farmers and consumers in a country only if the regulatory agency concludes that all national safety requirements are met and approves it for release.

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