Does maize ear husk cover inadequacy at harvest construe a correlation with Aspergillus section Flavi infection as dry spell would?

Abstract Sorting of maize ears based on husk cover at harvest may be considered as an approach to minimise the aflatoxin (AF) levels in maize grain intended for consumption. Aflatoxins are known natural human carcinogens produced by certain species of Aspergillus section (sect.) Flavi and impair livestock productivity. We investigated the influence of maize ear husk cover inadequacy on the natural infection of preharvest maize with Aspergillus sect. Flavi and contamination with AFs thereof. Additional investigated factors that may influence maize Aspergillus sect. Flavi infection and AF contamination were rainfall intensity, field burning, insect pest infestation, seed maturity and crop rotation. Maize and soil samples were collected over two seasons from two climatically contrasting regions of Zambia. One region was in the wetter Agro-Climatic Zone (ACZ) and another in the drier ACZ. Plate count technique on modified rose Bengal agar was used to quantify Aspergillus sect. Flavi densities in maize and soil. AF levels in maize were determined by High-Performance Liquid Chromatography with immunoaffinity column clean-up. Aspergillus sect. Flavi was present in soils. On maize, Aspergillus sect. Flavi was mainly detected under dry spell conditions despite being detected in all soils. Similarly, AF in maize was only detected under dry spell conditions. Findings showed that inadequate husk cover alone did not influence Aspergillus sect. Flavi infection of maize and subsequent AF contamination. Rather, dry spell with late rains predisposed the Aspergillus sect. Flavi infection and AF contamination. Insect pest incidence was the second most important factor aggravating the Aspergillus sect. Flavi infection.