Black Rot in Zea mays Caused by Olpitrichum tenellum in China

Since 1997, severe epidemics of a black rot disease of maize (Zea mays) have occurred at Yuanmou County, Yunnan Province, China. Olpitrichum tenellum, identified by morphology of conidia and conidiophores was recovered from infected plant material. Its strong infectivity on maize and causal role in inducing black rot was confirmed by pathogenicity tests in the greenhouse. This is the first report of black rot of maize caused by O. tenellum in China.