Leaf Spot and Stem Blight of Sweetpotato Caused by Alternaria bataticola: A New Record to South America. C. A. LOPES, Research Plant Pathologist, CNPH/EMBRAPA, C.P. 0218, 70359-970 Brasilia-DF, Brazil. L. S. BOITEUX, Research Plant Breeder, CNPH/EMBRAPA, C.P. 0218, 70359-970 Brasilia-DF, Brazil. Plant Dis. 78:1107-1 109. Accepted tor publication 4 August 1944. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1107.

A severe leaf spot and stem blight disease was observed on several sweetpotato genotypes at an experimental field and in commercial plantings of the cultivar Brazlandia Roxa in the Brasilia-DF area. An Alternaria sp. was consistently isolated from the lesions. Pathogenicity tests were done under greenhouse conditions (air temperature, 18-40°C) using a spore suspension adjusted to 5 × 104 conidia per milliliter. The same Alternaria sp. was reisolated from leaf and petiole lesions. Even though identified as A. bataticola, the Brazilian isolates completely lacked the forked beaks in the conidia that are characteristic of this species. This is apparently the first report of A. bataticola in South America, extending the geographic range of this pathogen to the New World.