First report of powdery mildew caused by Podosphaera xanthii on okra in China.
In recent years, okra (Abelmoschus esculentus) has become an important new vegetable crop in South China, with increasing acreage and growing economic value. In January 2018, powdery mildew on the cultivar Hongwufu was observed in a plastic greenhouse in Hainan Experimental Station of Northeast Agricultural University, Sanya, China. Powdery mildew colonies began as small white spots on both sides of the older leaves and then spread to entire leaves. Subsequently, younger leaves developed rapid symptoms, resulting in premature senescence of the leaves and reduced yield. All 120 okra plants in the greenhouse were severely infected. The causal pathogen was isolated and identified as Podosphaera xanthii based on morphological, molecular and pathogenicity analyses. This is thought to be the first report of powdery mildew caused by P. xanthii on okra in China.