**Mycotoxins in Flanders' Fields: Occurrence and Correlations with** *Fusarium* **Species in Whole-Plant Harvested Maize**

### **Jonas Vandicke 1,\*, Katrien De Visschere 2, Siska Croubels 3, Sarah De Saeger 4, Kris Audenaert 1 and Geert Haesaert 1,\***


Received: 18 October 2019; Accepted: 15 November 2019; Published: 18 November 2019

**Abstract:** Mycotoxins are well-known contaminants of several food- and feedstu ffs, including silage maize for dairy cattle. Climate change and year-to-year variations in climatic conditions may cause a shift in the fungal populations infecting maize, and therefore alter the mycotoxin load. In this research, 257 maize samples were taken from fields across Flanders, Belgium, over the course of three years (2016–2018) and analyzed for 22 di fferent mycotoxins using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. DNA of *Fusarium graminearum*, *F. culmorum* and *F. verticillioides* was quantified using the quantitative polymerase chain reaction (qPCR). Multi-mycotoxin contamination occurred frequently, with 47% of samples containing five or more mycotoxins. Nivalenol (NIV) was the most prevalent mycotoxin, being present in 99% of the samples, followed by deoxynivalenol (DON) in 86% and zearalenone (ZEN) in 50% of the samples. Fumonisins (FUMs) were found in only 2% of the samples in the wet, cold year of 2016, but in 61% in the extremely hot and dry year of 2018. Positive correlations were found between DON and NIV and between *F. graminearum* and *F. culmorum*, among others. FUM concentrations were not correlated with any other mycotoxin, nor with any *Fusarium* sp., except *F. verticillioides*. These results show that changing weather conditions can influence fungal populations and the corresponding mycotoxin contamination of maize significantly, and that multi-mycotoxin contamination increases the risk of mycotoxicosis in dairy cattle.

**Keywords:** Maize; mycotoxins; *Fusarium*; monitoring; forage; silage; maize ear rot; nivalenol; fumonisins
