Evaluation of Postemergence Fungicides and Application Method on Sugar Beet for Control of Rhizoctonia Crown and Root Rot in Northwest Minnesota, 2025

Rhizoctonia crown and root rot (RCRR), caused by Rhizoctonia solani, is the most common root disease of sugar beet in Minnesota and eastern North Dakota. Under favorable weather conditions, crown rot and root rot are evident often accompanied by chlorotic and wilting foliage. Typical root rot symptoms appear as dark brown to black lesions on the surface in a ladder-like pattern. In this study, we evaluated the efficacy of conventional fungicides applied postemergence as a 7-in. band or as a broadcast for managing RCRR. The trial was conducted at the University of Minnesota, Northwest Research and Outreach Center in Crookston, MN, on a moderately susceptible sugar beet variety ( Beta vulgaris ‘Crystal 793RR’). Results from this trial will help sugar beet growers in making informed management decisions for Rhizoctonia root rot.