First report of powdery mildew caused by Erysiphe betae on sugar beet in Korea.
During the winter of 2015 and spring of 2016, sugarbeet infected by a powdery mildew with approximately 20% disease incidence was found in a plastic greenhouse in Jeju, Korea Republic. Powdery mildew colonies first appeared as sparse white patches on both sides of the leaves. As the disease progressed, the plants were covered with abundant masses of conidia, resulting in reduced growth and premature senescence. The causal pathogen was identified as Erysiphe betae based on morphological, molecular and pathogenicity analyses. This is thought to be the first report of powdery mildew caused by E. betae on sugarbeet in Korea Republic.