Photo credit: James Karanja, KARI

May 28-June 1, 2012 (Dar es Salaam, Tanzania): As part of a multidisciplinary and multinational collaboration, a team of researchers representing several research institutions met to discuss the growing aflatoxin problem in sub-Saharan Africa.

The Capacity and Action for Aflatoxin Reduction in Eastern Africa (CAAREA) Midterm Workshop focused on the Aflatoxin Project being conducted by the Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub in partnership with Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO). The project aims to better understand the extent of aflatoxin contamination in maize in the region and to generate effective solutions.

Aflatoxins, a family of fungal toxins common to oily crops, are hazardous to the health of those who ingest them. Effects can range from stunted growth in children to Hepatocellular carcinoma (HCC-a common form of liver cancer), liver cirrhosis, and potentially death. Aspergillus flavus, a soil-borne fungus found throughout most farmers' fields, is the causal agent for aflatoxin generation in maize, groundnuts, and other crops.

With funding from the Australian Agency for International Development (AusAID), the CAAREA team comprised of the BecA–ILRI Hub together with Australia's national science agency CSIRO; the Kenya Agricultural Research Institute (KARI); the Agricultural Research Institute (ARI)- Uyole Tanzania; the Tanzania Ministry of Agriculture and Food Security; the University of Queensland/Queensland Alliance for Agriculture and Food Innovation; Cornell University; the Open University of Tanzania, the Queensland Government; HarvestChoice; and the University of Pretoria is leading a multipronged effort to:

  • establish a regional mycotoxin diagnostics platform at the BecA-ILRI Hub, including development of cost-effective detection methods suitable for use at other institutions and in the field throughout the region
  • identify maize varieties/germplasm with resistance to aflatoxin accumulation
  • map and model the climatic and other factors that put maize crops throughout Kenya, Tanzania and the region at risk of aflatoxin contamination

The partners are working to identify non-GM maize types that are resistant to aflatoxin accumulation. CSIRO and the HarvestChoice University of Minnesota node has teamed up with social scientists and bioscientists from KARI, ARI, the Tanzania Ministry of Agriculture and Food Security, the Open University of Tanzania, and the University of Pretoria to conduct an extensive survey of maize growers throughout Kenya and Tanzania to better understand:

  • the genetic landscape of maize grown throughout these two countries
  • the extent of aflatoxin found in farmers' maize crops at harvest
  • the risks of aflatoxin contamination at the time of harvest as a function of maize genotype, climate and management

To gain a better understanding of the farming practices of Kenyan and Tanzanian maize growers, researchers scouted farm locations in both countries, taking note of how maize is grown, harvested and stored, as well as climatic characteristics and pests. Understanding the realities faced by local farmers is critical for designing and implementing a spatially explicit farm survey that will help inform an analysis of the effects of climate variation on aflatoxin production as well as the the current landscape of maize susceptible and resistant to aflatoxin accumulation in farmers fields today.

The survey, developed by the CSIRO-HarvestChoice-University of Pretoria-KARI-ARI-Tz Min Ag team, will collect pre-harvest plant samples for genetic and diagnostic analysis. The identification of maize genotypes will help pinpoint those that may influence aflatoxin accumulation under different climates. The second portion of the survey will be an analysis of the aflatoxin levels in harvested maize. The aflatoxin concentration will then be compared with the local climate of each sample location to identify potential relationships between climate, genotype and concentrations of aflatoxins. The genotyping will be led by Andrzej Kilian of Diversity Arrays Technology (DArT),Australia, in collaboration with CSIRO and the BecA-ILRI Hub. The laboratory diagnostics work will be performed by researchers at the BecA-ILRI Hub, in collaboration with scientists from CSIRO and the University of Queensland. A pilot farm survey is scheduled for December of this year before the full scale survey which is scheduled to start during the first half of 2013. Researchers involved believe that the survey will develop a better understanding of the factors that put maize farms at greater risk of aflatoxin contamination. The associated database will be used to generate an aflatoxin risk map for Kenya and Tanzania, and will help in identification of promising strategies for reducing some of the aflatoxin risks.

Contributing researchers and organizations:
Project Leader: Jagger Harvey, BecA-ILRI Hub
Modelling Coordinator: Darren Kriticos, CSIRO-HarvestChoice
Jason Beddow and Philip Pardey, HarvestChoice-University of Minnesota
Andrzej Kilian, DArT
Frikkie Liebenberg, University of Pretoria
Arnold Angelo Mushongi, ARI-Uyole, Tanzania
Deogratias Lwezaura, Ministry of Agriculture and Food Security, Tanzania
Said Massomo, Open University of Tanzania
James Karanja and Anne Gichangi, KARI
Rebecca Nelson, Michael Milgroom and Samuel Mutiga, Cornell University
Mary Fletcher and Glen Fox, University of Queensland/QAAFI
Ross Darnell, Nai Tran-Dinh Stephen Trowell, Amalia Berna and Larelle McMillan, CSIRO
Benoit Gnonlonfin, Leah Ndungu, Immaculate Wanjuki, and James Wainaina, BecA-ILRI Hub
Yash Chauhan and Warwick Turner, Queensland Government, Agriculture, Fisheries, and Forestry

For more information: http://hub.africabiosciences.org/activities/research/299-capacity-and-action-for-aflatoxin-reduction-in-eastern-africa-caarea>

Citation

HarvestChoice, 2013. "Aspergillus and Aflatoxin in African Maize Farms." International Food Policy Research Institute, Washington, DC., and University of Minnesota, St. Paul, MN. Available online at http://harvestchoice.org/node/5271.

Mar 7, 2013