Weather-Related Variations of Mycotoxins in Maize: A 2024 Study from AP Vojvodina (Serbia) and the Republic of Srpska (Bosnia and Herzegovina)

Climate variability strongly affects fungal ecology and mycotoxin contamination patterns in maize. This study evaluated the influence of weather conditions during the 2024 growing season on the occurrence and co-occurrence of regulated and emerging mycotoxins in maize from two Southeast European regions: the Autonomous Province of Vojvodina (APV), Serbia, and the Republic of Srpska (RoS), Bosnia and Herzegovina (BIH). A total of 266 maize samples were analysed using an LC-MS/MS method targeting 21 fungal metabolites. The exceptionally hot and dry summer conditions, particularly the severe drought recorded in APV during August, were associated with regional differences in mycotoxin profiles. APV maize showed higher contamination with drought-related mycotoxins, especially aflatoxins, while fumonisins were highly prevalent in both regions. Overall, fumonisins were the dominant regulated mycotoxins (88.0%), followed by aflatoxins (41.4%) and T-2/HT-2 toxins (31.6%), whereas deoxynivalenol and zearalenone occurred less frequently. Emerging metabolites showed high prevalence, particularly alternariol monomethyl ether (86.5%), moniliformin (74.4%), and ergot alkaloids (53.4%). Co-occurrence analysis revealed 189 different combinations, with up to ten mycotoxins detected simultaneously. These findings demonstrate region-specific weather-driven shifts in maize contamination and emphasize the need for multi-mycotoxin monitoring strategies including both regulated and emerging contaminants.