Monitoring Fungicide Sensitivity of Cercospora beticola of Sugar Beet for Disease Management Decisions.

Cercospora leaf spot, caused by the fungus Cercospora beticola Sacc., is the most serious and important foliar disease of sugar beet (Beta vulgaris L.) wherever it is grown worldwide. Cercospora leaf spot first caused economic damage in North Dakota and Minnesota in 1980, and the disease is now endemic. This is the largest production area for sugar beet in the United States, producing 5.5 to 6.0 million metric tons on approximately 300,000 ha, which is 56% of the sugar beet production in the United States. This Plant Disease feature article details a cooperative effort among the participants in the sugar beet industry in this growing area and represents a successful collaboration and team effort to confront and change a fungicide resistance crisis to a fungicide success program. As a case study of success for managing fungicide resistance, it will serve as an example to other pathogen-fungicide systems and provide inspiration and ideas for long-term disease management by fungicides.