Variation in the production of trichothecene mycotoxin deoxynivalenol (DON) in spring barley varieties after treatment with the fungicides azoxystrobin and tebuconazole

Eight varieties of spring barley (<i>Hordeum vulgaris</i> Lin.) were artificially inoculated with a <i>Fusarium culmorum</i> (W.G. Smith) Saccardo – isolate and naturally infected in the middle of the flowering period, and 2 d later treated with the fungicides azoxystrobin or tebuconazol at a dose of 1 l/ha in 250 l of water. In both control and treated samples of grain the content of deoxynivalenol (DON), the main trichothecene mycotoxin produced by <i>F. culmorum</i>, was determined by gas chromatography (GC-ECD). The treatment with either fungicide resulted in elevated levels of DON, an effect that was more pronounced with azoxystrobin.