Baseline sensitivity and control efficacy of epoxiconazole against Fusarium graminearum in Henan Province, China

Abstract

Fusarium head blight (FHB), caused by Fusarium graminearum species complex (FGSC) is one of the most destructive wheat diseases worldwide. F. graminearum is the dominant pathogen of FHB in Henan Province. Epoxiconazole is a demethylation inhibitor (DMI) fungicide, and is the main fungicide for controlling FHB in China. In this study, 118 F. graminearum isolates were collected from different regions of Henan Province in 2016 and 2017. The sensitivity of these F. graminearum isolates to epoxiconazole was determined by the method of mycelial growth inhibition. The results showed that the EC50 values range of epoxiconazole to the tested F. graminearum isolates was 0.0196 to 0.5708 μg ml−1, and the mean EC50 value was 0.2178 ± 0.1178 μg ml−1 (mean ± SD). The sensitivity frequency distribution of these F. graminearum isolates to epoxiconazole was a continuous single peak curve, and no isolates resistant to epoxiconazole were found in Henan Province, China. The field control efficacy of epoxiconazole against F. graminearum was evaluated and the results showed that epoxiconazole had a significantly higher control efficacy on FHB, compared to the control fungicide carbendazim. The thousand grain weight of all the fungicide treatments was significantly higher than water control (without fungicide). This study showed that the DMI fungicide epoxiconazole has high activity and field control efficacy on F. graminearum, and can effectively control the prevalence of FHB.