Cercospora leaf spot (CLS), caused by Cercospora beticola, is the most destructive foliar disease in sugar beet. CLS is conventionally controlled with fungicide, but the emergence of fungicide-resistant populations reinforces the importance of developing and cultivating resistant varieties. Understanding the dynamics of CLS in different varieties is hence essential for sustainable CLS management. Field experiments (2022 and 2023) with four sugar beet varieties possessing different resistant properties were conducted to describe the relationship between the variety resistance and the disease epidemiology of C. beticola. For this purpose, spore flight and disease progression were assessed on a weekly basis. Disease severity (DS) and disease incidence (DI) were delayed in resistant varieties compared to the susceptible and moderately susceptible ones. This finding was further confirmed by a model-based analysis of DS and DI for all varieties. Weekly spore flight monitoring during the vegetation period showed a similar tendency of reduced spore quantity by the resistant varieties. This was probably due to the lower DS, as no differences were found when the amount of fungal DNA was determined in individual lesions from the different varieties. Analysis of relative yield loss further confirmed the advantage of growing resistant varieties. Our results highlight that resistant varieties delay disease onset resulting in less severe symptoms and reduced spore flight. We also proved that aerial spore flight intensity could reflect the resistant property of each variety. These results provide a deeper insight into the interaction between variety resistance and CLS epidemiology, emphasizing variety-specific CLS management. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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