Field efficacy of two atoxigenic biocontrol products for mitigation of aflatoxin contamination in maize and groundnut in Ghana

Daniel Agbetiameh,Alejandro Ortega-Beltran,Richard T Awuah,Joseph Atehnkeng,Abuelgasim Elzein,Peter J Cotty,Ranajit Bandyopadhyay

doi:10.1016/j.biocontrol.2020.104351

Abstract

Biological control is one of the recommended methods for aflatoxin mitigation. Biocontrol products must be developed, and their efficacy demonstrated before widespread use. Efficacy of two aflatoxin biocontrol products, Aflasafe GH01 and Aflasafe GH02, were evaluated in 800 maize and groundnut farmers’ fields during 2015 and 2016 in the Ashanti, Brong Ahafo, Northern, Upper East, and Upper West regions of Ghana. Both products were developed after an extensive examination of fungi associated with maize and groundnut in Ghana. Each product contains as active ingredient fungi four Aspergillus flavus isolates belonging to atoxigenic African Aspergillus Vegetative Compatibility Groups (AAVs) widely distributed across Ghana. An untreated field was maintained for each treated field to determine product efficacy. Proportions of atoxigenic AAVs composing each product were assessed in soils before product application, and soils and grains at harvest. Significant (P < 0.05) displacement of toxigenic fungi occurred in both crops during both years, in all five regions. Biocontrol-treated crops consistently had significantly (P < 0.05) less aflatoxins (range = 76% to 100% less; average = 99% less) than untreated crops. Results indicate that both biocontrol products are highly efficient, cost-effective, environmentally safe tools for aflatoxin mitigation. Most crops from treated fields could have been sold in both local and international food and feed premium markets. Adoption and use of biocontrol products have the potential to improve the health of Ghanaians, and both income and trade opportunities of farmers, aggregators, distributors, and traders.

Highlights

Contamination of key staple and/or cash crops by toxic fungal metabolites, aflatoxins, is an issue of significant public health and economic concern (Wu, 2015; JECFA, 2018)
Based on a previous study on the relative adaptation to maize and groundnut cropping systems, frequency of occurrence, and competitive potential to move to crops and limit crop aflatoxin content in three AEZs in Ghana (Agbetiameh et al, 2019), eight superior atoxigenic Aspergillus Vegetative Compatibility Groups (AAVs) were selected as active ingredient fungi for the formulation of two aflatoxin biocontrol products: Aflasafe GH01 and Aflasafe GH02
Efficacies of two aflatoxin biocontrol products were evaluated in maize and groundnut across three AEZs of Ghana for two successive years

Summary

Introduction

Contamination of key staple and/or cash crops by toxic fungal metabolites, aflatoxins, is an issue of significant public health and economic concern (Wu, 2015; JECFA, 2018). A wide range of crops including maize (Zea mays L.), groundnut (Arachis hypogaea L.), cottonseed (Gossypium spp.), pistachio (Pistacia vera L.), and almond (Prunus dulcis Mill.) are susceptible to infection by aflatoxin-producing fungi and subsequent aflatoxin contamination both in the field and after harvest (Cotty and Jaime-Garcia, 2007). With current climate change trends, the scope and prevalence of crop aflatoxin contamination is expected to increase worldwide (Battilani et al, 2016). Efforts to protect consumers from adverse health effects of aflatoxins have resulted in several nations promulgating and enforcing standards to limit aflatoxin levels in foods and feeds (GSA, 2001, 2013; van Egmond et al, 2007; JECFA, 2018). Several exporting nations, including Ghana, have lost both access to premium European markets and huge

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Conclusion