Effects of fungicides applied at anthesis on fusarium head blight and mycotoxins in wheat

Fusarium head blight (FHB) of wheat can cause yield losses of 30-70%. More importantly, affected grain may be less palatable to stock than healthy grain and may contain mycotoxins. A field trial in 2000/01 tested several fungicides and fungicide combinations for FHB control. FHB incidence was 9.1% in untreated plots The greatest reduction of FHB incidence, grain Fusarium and mycotoxins, was achieved with triazoles, a benzimadazole, or a combination of these. Strobilurin fungicides reduced FHB, although less effectively than the triazoles and carbendazim, but Fusarium incidence was greater in grain harvested from strobilurin-treated plots than in grain from untreated plots. Combining strobilurin fungicides with fungicides from other groups did not further reduce Fusarium levels in harvested grain. Nine Fusarium species and Microdochium nivale were isolated from grain harvested from the trial. Fusarium graminearum and F avenaceum were most commonly isolated, with E crookwellense and E culmorum also common.