Abstract:
Fusarium head blight (FHB), caused by
Fusarium graminearum, is one of the most important destructive diseases of wheat, which leads to the decline in wheat yield and quality. Difenoconazole, a triazole fungicide, is an exemplary demethylation inhibitor of ergosterol biosynthesis with broad-spectrum and high-efficiency fungicidal activity. In this study, 107 isolates of
Fusarium graminearum collected from Henan Province from 2016 to 2017 were assayed to determine their sensitivity to difenoconazole based on the mycelial growth inhibition by the fungicide. The results showed that difenoconazole had a high inhibitory effect on the mycelial growth of
F. graminearum, and the EC
50 value was in range of 0.0128 to 0.6079 mg/L with a normal distribution, and the mean EC
50 value was (0.2239 ± 0.1192) mg/L (mean ± SD). Spearman’s rho (
ρ) for the log
10 of the EC
50 values of 20 isolates of
F. graminearum between difenoconazole and epoxiconazole, carbendazim, phenamacril, pydiflumetofen, tebuconazole, prothioconazole, and metconazole were analysed. The sensitivity correlation analysis showed that there was low level correlation between difenoconazole and metconazole, but no correlation with other tested fungicides.Therefore, these sensitivity data could be used as the baseline sensetivity of
F. graminearum to difenoconazole in Henan Province and provide reference for the sensitivity monitoring to difenoconazole in the
F. graminearum population and fungicide reasonable application.