Effect of Timing of Fungicide Application on the Development of Fusarium Head Blight and the Accumulation of Deoxynivalenol (DON) in Winter Wheat Grain

The effect of different timings of fungicide applications on Fusarium head blight severity and mycotoxin accumulation in wheat grain was investigated in two field experiments. The fungicides metconazole, tebuconazole, azoxystrobin and mixtures of metconazole + azoxystrobin and tebuconazole + azoxystrobin were applied either, 5 days pre-, 2 days pre-, 2 days post-or 5 days post-inoculation of wheat ears with Fusarium spp. and Microdochium spp. at GS 65. Fungicides applied 2 days pre-or 2 days post-inoculation were most effective at reducing Fusarium head blight severity and DON concentration in grain. Metconazole and tebuconazole applied alone within two days of inoculation were most consistent in their effects on Tri5 DNA and DON in harvested grain.