First Report of Leaf Spot on Taro Caused by Epicoccum sorghinum in China

Colocasia esculenta (L.) Schoot (Araceae), commonly known as taro, is grown worldwide as a starch-rich tuber, and has been cultivated extensively in southern China. In May 2016, leaf spot symptoms of Guangxi Lipu (varying from 30–40 × 12–15 cm in size) were frequently observed on lower taro leaves in many commercial fields (paddy field soil) located in Zhangzhou, Fujian province, China (percentage of symptomatic plants and fields were 10% and 80%, separately) and disease severity was positively influenced by suitable temperatures (25°C to 30°C ) and high humidity. Symptoms first appeared as necrotic lesions, which then elongated and became yellowish to light-brown and the necrotic lesions became thinner and many black pycnidia were found. Then, leaf spots later coalesced, becoming large and irregular, with yellow margins and some lesions eventually perforated. In most spots, black pycnidia were found in the thinner mesophyll tissues, varying from 20–70 µm in diameter. Conidia were hyaline, unicellular, el...