Evaluation of DMI Fungicides to Manage Cercospora Leaf Spot on a Moderately Susceptible Sugar Beet Variety in Northwest Minnesota, 2025

Cercospora leaf spot (CLS), caused by Cercospora beticola, is the most devastating foliar diseases of sugar beet in Minnesota and North Dakota. CLS symptoms develop first on older leaves as small, circular, tan to brown spots becoming large necrotic lesions as the infections become severe, leading to reduced root and sugar yield. In this study, we evaluated the efficacy of DMI fungicides within a four-spray fungicide spray program for management of CLS. The trial was conducted at the Northwest Research and Outreach Center in Crookston, MN on a moderately susceptible sugar beet variety (Beta vulgaris ‘Crystal 912RR’). Results from this trial will help sugar beet growers make informed decisions on selecting a suitable DMI fungicide for managing CLS.