Chapter 9.15
9.15 - Biofortified Cassava
Jessica Detweiler, University of Guelph,Canada
Suggested citation for this chapter.
Detweiler,J. (2025) Biofortified Cassava. In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Introduction
Biofortification
is an agricultural practice which uses technological and/or breeding methods to improve the vitamin and mineral content of food crops; it has been applied to cassava, maize, rice, wheat, legumes, and many others (HarvestPlus A., n.d.; WHO, 2023; Van Ginkel & Cherfas, 2023). Biofortified crops are grown and consumed by approximately 50 million smallholder farmers, and there are efforts to increase this number to 1 billion people by 2030 (African Union, 2020; Van Ginkel & Cherfas, 2023). Biofortified cassava can provide 25%-100% of one’s daily vitamin A-intake needs, potentially increasing retinol-blood levels by 0.06 micromoles per litre (Olaosebikan et al., 2019; HarvestPlus, 2018; Mills et al., 2022).Cassava, also called ‘manioc’ or ‘yuca’ (Latin name: Manihot esculenta), is a rich source of carbohydrates and other vital nutrients (FAO et al., 2020; SeedChange, 2021). However, when cassava is biofortified, it can become particularly valuable for its micronutrient content—specifically vitamin A (HarvestPlus, 2018). Biofortified cassava, or ‘yellow cassava,’ is an improved crop variety that can be easily implemented into smallholder farming (Mills et al., 2022).
As previously mentioned, the biofortification of cassava aims to solve malnutrition issues relating to vitamin A deficiency. See subsection ‘Case: Nigeria’ for relevant quantitative data. The health benefits of vitamin A include the proper functioning and development of the body’s visual and immune systems (Chávez et al., 2005). Vitamin A deficiency reduces immunity and infection resistance, resulting in hundreds of thousands of cases of child blindness and related deaths per year (WHO C., n.d.).
Biofortified cassava is considered a resilient solution to vitamin A deficiency since cassava can grow in low-nutrient soils and is largely drought-resistant (SeedChange, 2021). It is also considered a long-term, stable solution for two reasons: 1) the increased vitamin A in biofortified varieties remains at constant levels due to the clone propagation technique used in the growing of cassava; and 2) for that reason, biofortified cassava only needs to be introduced one time for the benefits to persist in a given area (Chávez et al., 2005).
Biofortified cassava is an innovation that can solve malnutrition issues directly relating to smallholder farmers (SeedChange, 2021). Vitamin A deficiency is relevant to smallholder farmers because the livelihood of approximately 500 million farmers globally relies on cassava cultivation (SeedChange, 2021). Biofortified cassava is also relevant to solving micronutrient-related issues on a larger global scale; vitamin A deficiency is recognized as a public health concern in less-developed countries (Akhtar et al., 2013). Some less-developed countries that have both relatively high levels of vitamin A deficiency and fresh cassava production include Nigeria, Indonesia, Thailand, the Democratic Republic of the Congo, and Brazil (FAO, 2000; Micronutrient Initiative et al., 1998; FAO, n.d.).
Implementation
The following includes instructions on how to implement biofortified cassava. The cultivation process and results are the same as those for regular (i.e. non-biofortified) cassava varieties.
How to Obtain and Access
For agricultural purposes, cassava is propagated from stem cuttings, also called vegetative tissues or propagules (SeedChange, 2021). Therefore, once the genetic material (“germplasm”) of a biofortified cassava variety is obtained and introduced, the planting material can remain available in the given area (FAO, 2013).
CIAT Colombia provides germplasm to smallholder farmers from 261 institutions and countries (Alliance of Bioversity International and CIAT, n.d.; Genesys B., n.d.). The platform for online order requests from genebanks is called Genesys (Genesys A., n.d.). Some of the institutions which provide improved cassava varieties include the Brazilian Agricultural Research Corporation (EMBRAPA), the Plant Genetic Resources Research Institute in Ghana (CSIR-PGRRI), the National Plant Genetic Resources Centre in Zambia (SPGRC), and the Institute of Plant Breeding-National Plant Genetic Resources Laboratory at the University of Philippines (NPGRL, UPLB) (Genesys B., n.d.). The links to access the Genesys database, as well as these four additional resources, are listed in the section ‘Practical Links to get Started.’ Additionally, numerous community seed banks established in various countries also provide biofortified cassava varieties (Chávez et al., 2005).
Associated Costs and Inputs
Purchasing and growing biofortified crop varieties does not cost farmers more than non-biofortified varieties (HarvestPlus B, n.d.). In fact, implementing biofortified cassava can potentially save farmers money; biofortified crops typically cost US$15 to US$20 per year compared to US$37 to US$52 for other techniques used to increase vitamin A intake (HarvestPlus B., n.d.; African Union, 2020).
Very few additional inputs are needed to grow cassava, and as such there are no additional technological inputs or costs required to maintain biofortified varieties (FAO, 2013).
An important and regionally dependent factor for successful cassava growth—as with any farmed crop—is the choice of variety. Multiple biofortified varieties have been developed by professional breeders, and it is important to select the one most suited for a local growing environment (Tagliapietra et al., 2021).
Disease and Pest Management
A significant aspect of cassava cultivation is its high vulnerability to disease and pathogens (FAO, 2013). Cassava commonly suffers from cassava mosaic virus and brown-streak virus (Agrio, n.d.; Robson et al., 2023). It is important to note that both biofortified and non-biofortified cassava varieties are equally as vulnerable to these viruses—in addition to fungi, bacterial blights, and pests like weevils and beetles (Robson et al., 2023; Adeoti et al., 2023).
The following subsection includes quantitative data—in terms of micronutrient content improvement—from a case study of the implementation of biofortified cassava in Nigeria.
The second subsection highlights the importance of this innovation to women smallholder farmers, children, and pregnant women
Case Study: Nigeria
Nigeria is the world’s largest cassava producer and consumer, with smallholder farmers being the country’s primary producers (Olaosebikan et al., 2019; Mills et al., 2022).
Vitamin A deficiency is also a great concern in Nigeria, as nearly one-third of children under 5 years of age and one-fifth of pregnant women are vitamin A-deficient (Olaosebikan et al., 2019; Mills et al., 2022).
Because of these two factors, biofortified cassava serves as an efficient solution to the country’s vitamin A deficiency crisis.
Consumption of this improved variety of cassava can provide up to 25% of the body’s daily requirements of vitamin A, with other sources suggesting this number could actually be as high as 100% (Olaosebikan et al., 2019; HarvestPlus, 2018).
A study in regions of Nigeria reported that preschoolers who consumed biofortified cassava received 221 µg of retinol activity equivalents per day, while those who consumed regular cassava received 74 µg (Mills et al., 2022). The study’s results showed that consuming biofortified cassava can cause an increase of 0.06 µmol/L of retinol in the blood (Mills et al., 2022). This directly improves eye health as retinol is required for healthy vision (WHO B., n.d.).
Women Smallholder Farmers, Pregnant Women, and Children
Biofortified cassava is especially beneficial for women and children because vitamin A deficiency is related to higher susceptibility to illness and mortality and lower immunity rates in children, pregnant women, and women of menstruating age (Akhtar et al., 2013).
Due to the rapid growth of pregnant women and preschool-aged children, these two groups are the most vulnerable to vitamin A deficiency and, therefore, require increased vitamin A compared to other demographics (Maziya-Dixon et al., 2006; Akhtar et al., 2013).
Globally, 25% of children in less-developed countries have vitamin A deficiency (Mason et al., 2001). In general, the consequence of micronutrient deficiencies is overall poor health, hence weakened labour and academic performance. However, severe symptoms of vitamin A deficiency include several types of blindness, further weakening these crucial daily activities (WHO B., n.d.).
How this relates to women smallholder farmers: Women are traditionally responsible for managing household nutrition. For this reason, having access to biofortified cassava can reduce vitamin A deficiency in their families and children (Olaosebikan et al., 2019). Also, in certain regions where demand is higher, women are more involved in the cultivation and selling of biofortified cassava compared to their male counterparts, meaning biofortified cassava may provide a stronger income opportunity for women smallholder farmers (Olaosebikan et al., 2019).
Practical Links to get Started
I. How to grow cassava: https://www.youtube.com/watch?v=80_c8kmKRyo
II. Information on the detoxification process of cassava: https://www.fao.org/4/t0554e/t0554e06.htm#:~:text=Boiling%2FCooking,Cooke%20and%20Maduagwu%2C%201978
III. Information on the implementation of biofortified crops in Nigeria, including biofortified cassava: https://www.youtube.com/watch?v=8VAIQ4ruNTc
IV. Detailed information on biofortification of cassava for Africa: https://www.youtube.com/watch?v=7gMML7dYpvQ
V. Brief overview of biofortification: https://www.youtube.com/watch?v=CWukNqjX7AQ
VI. Information on biofortification's impacts on hunger and nutrient deficiencies: https://www.youtube.com/watch?v=ldXj_O-Cyx8
VII. Information on improved nutrition from biofortified cassava: https://www.youtube.com/watch?v=80_c8kmKRyo
VIII. Information on intensification of cassava production: https://www.fao.org/4/i3278e/i3278e.pdf
IX. Further scientific reading on biofortification: https://doi.org/10.1201/9781032690636
IX. Link to request germplasm at CIAT: https://alliancebioversityciat.org/genebank-germplasm-requests#/?filter=v2yzae38jpK&p=0 or email: alliance-grp-distributions@cgiar.org
X. To request germplasm from Genesys: https://www.genesys-pgr.org/
XI. Other genebanks and sources for genetic material:
EMBRAPA (Brazil) - https://www.embrapa.br/en/international
CSIR-PGRR (Ghana) - https://pgrri.csir.org.gh/
SPGRC (Southern Africa) - https://www.sadc.int/
NPGRL, UPLB (Philippines) - https://agora.uplb.edu.ph/
References
1. Action Against Hunger. (2022). Biofortification: Operational recommendations. https://www.actioncontrelafaim.org/wp-content/uploads/2022/01/Biofortification-Recommandations-operationelles-EN-VF.pdf.
2. Adeoti, J. et al. (2023). Susceptibility of processed and stored cassava, plantain, yam, and cocoyam to coffee bean weevil. The Journal of Basic and Applied Zoology, 84, 20. https://doi.org/10.1186/s41936-023-00341-x.
3. African Union. (2020). Upscaling biofortification in Africa: A roadmap. https://au.int/sites/default/files/documents/41149-doc-Roadmap_-_Upscaling_Biofortification_in_Africa_-_Final_-_Eng.pdf.
4. Akhtar, S., et al. (2013). Prevalence of vitamin A deficiency in South Asia: Causes, outcomes, and possible remedies. Journal of Health, Population and Nutrition, 31 (4), 413–423. https://doi.org/10.3329/jhpn.v31i4.19975.
5. Alliance of Bioversity International and CIAT. (n.d.). Genebank germplasm requests. CGIAR. https://alliancebioversityciat.org/genebank-germplasm-requests#.
6. Chávez, A. L., et al. (2005). Variation of quality traits in cassava roots evaluated in landraces and improved clones. Euphytica, 143, 125–133. Springer Nature. https://doi.org/10.1007/s10681-005-3057-2.
7. Chow, J., et al. (2010). Cost-effectiveness of "golden mustard" for treating vitamin A deficiency in India, PLoS One 5 (8), e12046. https://doi.org/10.1371/journal.pone.0012046.
8. FAO, IFAD, UNICEF, WFP and WHO. (2020). The state of food security and nutrition in the world 2020. Transforming food systems for affordable healthy diets. FAO, Rome. https://doi.org/10.4060/ca9692en.
9. Food and Agriculture Organization. (n.d.). FAOSTAT: Crops and livestock products. FAO, Rome. https://www.fao.org/faostat/en/#data/QCL.
10. Food and Agriculture Organization. (2000). World cassava situation and recent trends. The world cassava economy: Facts, trends and outlook. FAO, Rome. https://www.fao.org/4/x4007e/X4007E04.htm.
11. Food and Agriculture Organization of the United Nations. (2013). Cassava, a 21st century crop. Save and Grow: A guide to sustainable production intensification. FA0, Rome. https://www.fao.org/4/i3278e/i3278e01.pdf.
12. Genesys A. (n.d.). Home page. https://www.genesys-pgr.org/.
13. Genesys B. (n.d.). Provenance of PGRFA. https://www.genesys-pgr.org/iso3166.
14. Global Agriculture and Food Security Program. (2021). Cassava and rice recovery: Bolstering agriculture for a stronger Liberia. https://www.gafspfund.org/news/cassava-and-rice-recovery-bolstering-agriculture-stronger-liberia.
15. HarvestPlus A. (n.d.). FAQs. Biofortification hub. HarvestPlus. https://www.harvestplus.org/biofortification-hub/faqs/.
16. HarvestPlus B. (n.d.). Marshalling evidence. Enriching 100 million lives. https://www.harvestplus.org/home/biofortification-evidence/.
17. HarvestPlus. (2018). 2018 annual report. Catalyzing Biofortified Food Systems. https://www.harvestplus.org/wp-content/uploads/2022/01/HarvestPlus-2018-Annual-Report.pdf.
18. Mason, J. B., et al. (2001). The micronutrient report: Current progress and trends in the control of vitamin A, iodine, and iron deficiencies. The Micronutrient Initiative. https://www.nutritionintl.org/wp-content/uploads/2017/06/The-Micronutrient-Report-Current-Progress-and-Trends-in-the-Control-of-Vitamin-A-Iodine-and-Iron-Deficiencies.pdf.
19. Maziya-Dixon, B., et al. (2006). Vitamin A deficiency is prevalent in children less than 5 y of age in Nigeria. Journal of Nutrition, 136(8), 2255–2261. https://doi.org/10.1093/jn/136.8.2255.
20. Micronutrient Initiative, UNICEF, & Tulane University. (1998). Progress in controlling vitamin A deficiency. The Micronutrient Initiative. https://idl-bnc-idrc.dspacedirect.org/server/api/core/bitstreams/5aad8a3c-705e-42bd-b773-3cc38264a874/content.
21. Mills, K., et al. (2022). Global disparities of hypertension prevalence and control: A systematic analysis of population-based studies from 90 countries. Circulation 134 (6), 441–450. https://doi.org/10.1161/CIRCULATIONAHA.115.018912.
22. Njenga, P., et al. (2014). Combining ability for beta-carotene and important quantitative traits in a cassava F1 population. Journal of Plant Breeding and Crop Science, 6 (2), 24–30. https://doi.org/10.5897/JPBCS12.069.
23. Olaosebikan, O., et al. (2019). Gender-based constraints affecting biofortified cassava production, processing, and marketing among men and women adopters in Oyo and Benue States, Nigeria. Physiological and Molecular Plant Pathology, 105, 17–27. https://doi.org/10.1016/j.pmpp.2018.11.007.
24. Reddy, V. (2002). History of the international vitamin A consultative group 1975-2000. Journal of Nutrition, 132 (9), 2852S–2856S. https://doi.org/10.1093/jn/132.9.2852S.
25. Robson, F., et al. (2023). Cassava brown streak: A deadly virus on the move. Plant Pathology, 73 (2), 221-241. https://doi.org/10.1111/ppa.13807.
26. SeedChange. (2021). Where is cassava from? https://weseedchange.org/where-is-cassava-from/.
27. Tagliapietra, B. L., et al. (2021). Nutritional quality and sensory acceptance of biofortified cassava. Brazilian Journal of Food Technology, 24, e2020247. https://doi.org/10.1590/1981-6723.24720.
28. Thresh, J., & Cooter, R. (2005). Strategies for controlling cassava mosaic virus disease in Africa. Plant Pathology, 54 (5), 587–614. https://doi.org/10.1111/j.1365-3059.2005.01282.x.
29. Van Ginkel, M., & Cherfas, J. (2023). What is wrong with biofortification? Global Food Security 37, 100689. https://doi.org/10.1016/j.gfs.2023.100689.
30. World Health Organization A. (n.d.). Health topics: Food fortification. https://www.who.int/health-topics/food-fortification#tab=tab_1.
31. World Health Organization B. (n.d.). Nutrition and Food Safety. Vitamin and Mineral Nutrition Information System. https://www.who.int/teams/nutrition-and-food-safety/databases/vitamin-and-mineral-nutrition-information-system/data.
32. World Health Organization C. (n.d.). Vitamin A deficiency. Nutrition Landscape Information System. https://www.who.int/data/nutrition/nlis/info/vitamin-a-deficiency.
33. World Health Organization. (2023). Biofortification of staple crops. e-Library of Evidence for Nutrition Actions. https://www.who.int/tools/elena/interventions/biofortification.
34. Yadav, D., et al. (2020). Advantage of biofortification over fortification technologies. Wheat and Barley Grain Biofortification, 257–273. Woodhead Publishing. https://doi.org/10.1016/B978-0-12-818444-8.00010-9.