Abstract
Cercospora leaf spot (CLS) is one of the most detrimental leaf diseases of sugarbeet and of high economic importance for many sugarbeet production regions worldwide. In 2024, the Eastern commercial growing areas of North America experienced an extraordinary growing season that was characterized by exceptionally high disease pressure of CLS compared to average years. A main driver was favorable weather for CLS development, placing extreme demands on the available CLS management tools, from the use of fungicides and crop rotation to varieties. Even with CR+® hybrids, which have demonstrated high levels of CLS protection over the past three years, CLS control was often challenging in 2024. Contributing factors are currently under analysis including a potential adaptation of the Cercospora population in different growing regions. The composition of the Cercospora population is addressed by KWS large scale monitoring and carried out with isolate specific markers. Continual improvements in the CLS tolerance through breeding and the optimization of other available measures are needed to control CLS effectively.