First report of Alternaria brown spot of citrus caused by Alternaria alternata in Yunnan Province, China.
In 2003, in southern Wenshan Municipality, Yunnan Province, China, sporadic occurrence of Alternaria brown spot was observed on Tangfang mandarin (Citrus reticulata), a local citrus cultivar identified preliminarily as a kind of mandarin hybrid. From 2006 to 2008, nearly 80% of local orchards were infected with the disease. Fruit symptoms typical of Alternaria brown spot ranging from light brown, slightly depressed spots to circular and dark brown areas were observed. Leaves showed small, brown, circular spots and irregular blighted areas with characteristic yellow halos. The pathogen was identified as Alternaria alternata on the basis of conidial morphology. This is thought to be the first report of Alternaria brown spot of citrus in China.