Prevalence of Aflatoxin Contamination along the Groundnut Value Chain Actors in Different Agro-Ecology and Evaluation of Groundnut Varieties for Resistant to Aspergillus flavus and Aflatoxin Contamination in Eastern Ethiopia

Aflatoxins are common contaminants in groundnut and pose considerable risk to human health and have significant economic implication. Although, aflatoxin contamination of groundnut could occur in the field,in storage and during marketing, the level of contamination may vary along the value chain. The objective of this study was to determine level of aflatoxin concentration in groundnut along the value chain actors, and to evaluate groundnut varieties for resistant to A. flavus infection and aflatoxin contamination in Eastern Ethiopia. A total of 120 groundnut samples, which is 45 from farmers’ fields, 45 from farmers’ stores, and 30 from open air vendors, were collected and analysed for aflatoxin contamination in an ELISA test. Moreover, sixteen groundnut varieties were evaluated in this study. Field seed infection and colonization by A. flavus was determined using plate counting methods. The result revealed that, the level of aflatoxin contamination significantly varies along the value chain. Out of the total 120 samples, aflatoxin was detected on 91 samples, ranging from 1 ppb to 1012 ppb. Aflatoxin concentration were above 15 ppb in 85% of the positive samples collected from farmers’ stores at Fedis district. Moisture contents and aflatoxin level of groundnut samples were positively correlated (r = 0.956) and significant (p ≤ 0.05). There was also a significant and positive correlation (r = 0.959) between A. flavus infection and total aflatoxin levels. Moreover, the result revealed that all tested varieties were significantly different (p ≤ 0.05) in response to A.flavus infection and aflatoxin levels. Among the varieties evaluated, Baha Gudo (13.70%), Sartu (14.00%) and Sedi (14.23%) were resistant to A.flavus infection. Inaddition, Baha Gudo (1.93 ppb), Sartu (3.70 ppb) and Sedi (6.40 ppb) were resistant to aflatoxin contamination. We suggest pre-harvest and post- harvest management of A. flavus infection so as to reduce the level of aflatoxin contamination at farmers’ fields and farmers’ stores and to maintein the quality of groundnut along the value chain. Also the varieties that showed resistance could form part of an integrated management of aflatoxin contamination in Eastern Ethiopia. Keywords: Aflatoxin, Aspergillus flavus, Groundnut Varieties, Reaction, Value chain