Fungal and mycotoxin contamination in Bt maize and non-Bt maize grown in Argentina

Abstract

A Bt maize hybrid and its non-transgenic counterpart harvested during 2002/2003 and 2003/2004 harvest seasons from different locations within the maize-growing area in Argentina were compared for fungal and mycotoxin contamination. Fusarium species were the most prevalent on both genotypes with an isolation frequency >60% across all locations. The percentage of infection was lower in Bt maize than in non-Bt maize (P<0.05). There were no statistical differences in infection percentage due to genotype, fungicide treatment and their interactions. Fumonisins were detected in all of the samples from all locations and genotypes. Total fumonisin levels (fumonisins B 1 , B 2 and B 3 ) in the Bt and the non-Bt hybrid were significantly different (P<0.001), with lower toxin levels in the Bt maize in all locations but one evaluated during the two harvest season. There was no significant difference in deoxynivalenol levels between Bt and non-Bt maize. Application of the fungicide tebuconazole did not alter either the infection or the toxin levels in the Bt and non-Bt maize hybrid.