Ensuring the safety of African food crops

aflasafeâ„¢ team: Ranajit Bandyopadhyay, Joseph Atehnkeng, Charity Mutegi, Joao Augusto, Juliet Akello, Adebowale Akande, Lawrence Kaptoge, Fen Beed, Olaseun Olasupo, Tahirou Abdoulaye, Peter Cotty, Abebe Menkir, and Kola Masha, with several national partners

Ground-breaking research by scientists at IITA and partners is ensuring safe food and health for Africans.

IITA, in collaboration with the United States Department of Agriculture – Agricultural Research Service (USDA-ARS) and the African Agriculture Technology Foundation (AATF), has developed a natural, safe, and cost-effective biocontrol product that drastically cuts aflatoxin contamination in African food crops.

Aflatoxins are highly toxic chemical poisons produced mainly by the fungus Aspergillus flavus in maize and groundnut, and on yam chips, but which also affect other high-value crops such as oilseeds and edible nuts. The fungal chemicals cause liver cancer and also suppress the immune system, retard growth and development, lead to chronic liver disease and cirrhosis, and death in both humans and animals. Livestock are also at risk and poultry are particularly susceptible. Cattle are not so susceptible but if they are fed with contaminated feed the toxin “Aflatoxin M1” passes into the milk.

The biocontrol product – aflasafe™ uses native strains of A. flavus that do not produce aflatoxins (called atoxigenic strains) to “push out” their toxic cousins so that crops become less contaminated in a process called “competitive exclusion”. When appropriately applied before the plants produce flowers these native atoxigenic strains completely exclude the aflatoxin producers.

IITA recommends broadcasting 10 kg/ha aflasafe™ by hand on soil 2–3 weeks before the flowering stage of maize to prevent the aflatoxin- producing fungus from colonizing and contaminating the crop while it remains in the field and subsequently in storage. Even if the grains are not stored properly, or get wet during or after harvest, the product continues to prevent infestation and contamination.

The reduction of aflatoxin in maize fields is greater with the application of aflasafe™ than with the deployment of putative low-aflatoxin maize lines. For example, field studies during 2010 and 2011 in Nigeria established that aflatoxin reduction was 16–72%, due to resistant maize hybrids, 80–92% with aflasafe™, and 80–97% with the combined use of resistance and aflasafe™.

Field testing of aflasafe™ in Nigeria between 2009 and 2012 consistently showed a decrease in contamination in maize and groundnut by 80–90% or more.

In 2009, Nigeria’s National Agency for Food and Drug Administration and Control registered aflasafe™ and permitted treatment of farmers’ fields to generate the data on product efficacy for obtaining full registration. In 2011, IITA distributed about 14 t of aflasafe™ to more than 450 maize and groundnut farms, enabling farmers to achieve an 83% reduction in contamination.

The success of the project has led to the expansion of biocontrol research in Burkina Faso, Ghana, Kenya, Mozambique, Senegal, Tanzania, and Zambia.

Between 2004 and 2006, nearly 200 Kenyans died after consuming aflatoxin-contaminated maize. In 2010 over 2 million bags of maize in Kenya’s Eastern and Central provinces were found to be highly contaminated and were declared as non-tradable.

Research conducted by Leeds University and IITA found that 99% of children at weaning age are exposed to health risks linked to aflatoxin in Bénin and Togo.

Across the world, about US$1.2 billion in commerce is lost annually due to aflatoxin contamination, with African economies losing $450 million each year. Aflatoxins are also non-tariff barriers to international trade since agricultural products are rejected that have more than the permissible levels of contamination (4 ppb for the European Union and 20 ppb for USA).

IITA has identified separate sets of four competitive atoxigenic strains isolated from locally grown maize to constitute a biocontrol product called aflasafe KE01â„¢ in Kenya and aflasafe BF01 in Burkina Faso and aflasafe SN01 in Senegal.

The adoption of this biocontrol technology with other management practices by farmers will reduce contamination by more than 70% in maize and groundnut, increase crop value by at least 5%, and improve the health of children and women.

In 2012, G20 leaders launched a new initiative – AgResults – which included aflasafe™ in Nigeria as one of the first three pilot projects to encourage the adoption of agricultural technologies by smallholder farmers.

IITA’s experience in Nigeria has shown that the cost of biocontrol (about $1.5/kg with a recommended use of 10 kg/ha) is affordable for most farmers in the country.

The biocontrol product aflasafe SN01 can potentially reinstate groundnut exports to the European Union lost by Senegal and The Gambia due to aflatoxin contamination. The World Bank has estimated that in Senegal, an added capital investment cost of $4.1 million and 15% recurring cost would attract a 30% price differential to groundnut oil cake. Exports are expected to increase from 25,000 to 210,000 t. The increased export volume and price would annually add $281 million to groundnut exports. For confectionery groundnut, adherence to good management practices would increase export value by $45 million annually.

Currently, a demonstration-scale manufacturing plant for aflasafeâ„¢ is under construction at IITA with a capacity to produce 5 t/h. Market linkages between aflasafeâ„¢ users, poultry producers, and quality conscious food processors are also being created to promote aflasafeâ„¢ adoption, in collaboration with the private sector.

Costs and benefits
Biocontrol of aflatoxin is one of the most cost-effective control methods, with the potential to offer a long-term solution to aflatoxin problems related to liver cancer in Africa. Cost-effectiveness ratio (CER) of treating all maize fields in Nigeria with aflasafeâ„¢ is between 5.1 and 9.2, rising to between 13.8 and 24.8 if treatments were restricted to maize intended for human consumption. Up to 162,000 disability-adjusted life years (DALYs) can be saved annually by biocontrol in Nigeria.

Initial data from a separate study in Nigeria suggest that farmers will receive a return of from 20 to 60% on investment in aflasafeâ„¢ from the sale of maize harvested from treated fields to poultry feed manufacturers and quality-conscious food processors.

Donor support
Research and development efforts on aflasafe™ have been supported by the following donors: Bill & Melinda Gates Foundation, USAID, USAID-FAS, AATF, Commercial Agriculture Development Project of the Government of Nigeria, The World Bank, Austrian Development Cooperation (ADC), Deutsche Gesellschaft für Internationale Zusammenarbeit, GmbH (GIZ), the European Commission (EC KBBE-2007-222690-2 MYCORED), and Meridian Institute. In addition, IITA has received support from Belgium, Denmark, The German Federal Ministry for Economic Cooperation and Development (GTZ BMZ), Ireland, Norway, Sweden, Switzerland, and the UK Department for International Development (DFID).

References
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Atehnkeng, J., P.S. Ojiambo, T. Ikotun, R.A. Sikora, P.J. Cotty, and R. Bandyopadhyay. 2008. Evaluation of atoxigenic isolates of Aspergillus flavus as potential biocontrol agents for aflatoxin in maize. Food Additives and Contaminants 25 (10): 1266-1273.
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Oluwafemi, F., M. Kumar, R. Bandyopadhyay, T. Ogunbanwo, and K.B. Ayanwande. 2010. Bio-detoxification of aflatoxin B1 in artificially contaminated maize grains using lactic acid bacteria. Toxin Reviews 29 (3-4): 115-122.
Wu, F. and Khlangwiset, P. 2010. Health and economic impacts and cost-effectiveness of aflatoxin-reduction strategies in Africa: case studies in biocontrol and postharvest interventions. Food Additives and Contaminants: Part A, 27: 496-509.

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