First report of Clonostachys rosea causing root rot of Beta vulgaris in North Dakota, USA.
In August 2018, sugar beet plants (Beta vulgaris) with dull green and chlorotic foliage were observed in Hickson, North Dakota, USA. The taproots were found to have several circular brown to black necrotic lesions and the disease incidence was about 5%. The causal pathogen was isolated and identified as Clonostachys rosea based on morphological characteristics, molecular data (sequence analysis of the internal transcribed spacer (ITS1F/ITS4)), pathogenicity tests. This is thought to be the first report of C. rosea causing root rot of sugar beet in the USA, or worldwide.