Aspergillus section Flavi populations from field maize in Argentina

Aims: Populations of Aspergillus section Flavi were studied from a commercial field of maize in Rio Cuarto, Cordoba, Argentina. Methods and Results: The Aspergillus species were isolated from soil, debris and insects during three periods: pre-planting, growing maize and post-harvest. The colony count from non-rhizospheric soil in the pre-planting period was higher than in growing maize and the post-harvest period. Debris samples analysed during all periods showed similar infection percentages for Aspergillus section Flavi. The samples of insects collected during the maize-growing period showed a lower percentage of Aspergillus isolates than the samples from soil and debris. Aflatoxigenic strains were present in lower levels in each component of the agroecosystem studied. All the strains that produced sclerotia were L strains. Conclusions: In this field agroecosystem, the only strains with a high probability for transfer to the storage agroecosystem were L strains with low toxigenic potential. Significance and Impact of the Study: Maize pre-harvest contamination with aflatoxigenic inoculum was not significant.