Dynamics of mycotoxin occurrence in farm-stored maize in Merawi district, Ethiopia

Admasu Fanta Worku; Karta Kaske Kalsa; Nigus Gabbiye Habtua; Tenagashaw Mesfin Wogayehua; Merkuz Abera; Hadush Tsehaye; Fetien Abay; Bhadriraju Subramanyam; Helge Skinnes

doi:10.20372/pjet.v1i1.1200

Admasu Fanta Worku Bahir Dar University, Bahir Dar Institute of Technology
Karta Kaske Kalsa Department of Technology Multiplication and Seed Research, Ethiopian Institute of Agricultural Research, P.O. Box 2003, Addis Ababa, Ethiopia.
Nigus Gabbiye Habtua Faculty of Chemical and Food Engineering, Bahir Dar Institute of Technology, Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia.
Tenagashaw Mesfin Wogayehua Faculty of Chemical and Food Engineering, Bahir Dar Institute of Technology, Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia.
Merkuz Abera College of Agriculture and Environmental Sciences, Bahir Dar University, P.O. Box 5501, Bahir Dar, Ethiopia.
Hadush Tsehaye Department of Dryland Crop and Horticultural Sciences, Mekelle University, P.O. Box 231, Mekelle, Ethiopia
Fetien Abay Department of Dryland Crop and Horticultural Sciences, Mekelle University, P.O. Box 231, Mekelle, Ethiopia
Bhadriraju Subramanyam Department of Grain Science and Industry, Kansas State University, Manhattan, KS, 66506, USA
Helge Skinnes Norwegian University of Life Sciences, P.O. Box 5003, N-1432, Ã…s, Norway

DOI: https://doi.org/10.20372/pjet.v1i1.1200

Keywords: Farm storage, maize, mycotoxin development, Merawi, Ethiopia

Abstract

A study was conducted to investigate the progressive development of mycotoxins in farm-stored maize in Merawi district, Ethiopia. Thirty farming households were randomly selected as sampling units, from which 30 maize samples were collected each month from the last part of the dry season (March 2015) and through the wet season until August 2015. Total aflatoxins (AFT), total fumonisins (FUM), and deoxynivalenol (DON) were measured using lateral flow immunoassays. Results indicated that incidences of AFT, FUM, and DON in the overall samples (N = 180) were 81.1%, 8.9%, and 4.4%, respectively. AFT contamination levels were highest in May- June and lowest in March and July. The highest level of FUM was observed in August. Deoxynivalenol (DON) was detected only in July-August, coinciding with the peak rainfall months. Regardless of the sampling month, levels of AFT, FUM, and DON in positive samples ranged from 2.5 to 29.3 Âµg/kg, 0.20 to 0.75 mg/kg, and 0.32 to 2.9 mg/kg, respectively. The AFT level showed an increasing trend across sampling months until June and decreased in July-August. The AFT levels correlated positively with the percentage of insect-damaged kernels (IDK) (r = 0.31). The proportion of samples contaminated with at least one mycotoxin was 84.4% (N = 180). The co-occurrence of two or three mycotoxins was observed in 8.9% (N = 180), of which 5.6% (N = 180) were observed in samples collected in July-August. This is the first report of a periodically monitored observation of mycotoxin development in farm-stored maize in Ethiopia. The results demonstrate the need to have a bigger picture of the magnitude of mycotoxins contamination across the storage period in our maize growing area. The finding of insect infestation is useful as a background to implement new intervention measures like hermetic storage during on-farm maize storage to reduce the impact of mycotoxins.