LETTER TO THE EDITORS

 

Alternaria alternata (Fr.) Keissier, A PATHOGEN ASSOCIATED WITH Ipomoea batata (L.) Lam.

Dear Sir:

Sweet potato (Ipomoea batata (L.) Lam) is one of the most popular crops in Cuba. It is widely consumed comprising an important constituent of the daily diet of Cubans. This crop has been affected in some degree by a fungus in the last two years, and distinctive symptoms have been observed in some clones in our country.

In a sweet potato field at the "La Asunción" farm in San José de las Lajas, Havana Province, the plant foliage was found to be affected in a 80% with a fungal disease in July 2007. The diseased plants pertaining to CEMSA 78 354 clone showed leaf spots, which, in some cases, coalesced to form medium to big affected areas. These spots presented concentric areas surrounding a central dot. Initially, they appeared with a light coffee colour that became brown afterwards. Some plants presented stem blight. In the laboratory, Alternaria alternata (Fr.) Keissier was found to be the pathogen associated with the above symptoms. To corroborate the causal agent, a trial was carried out inoculating with the pathogen at 10⁵ s/mL. The same symptoms occurred and A. alternata was found as the associated pathogen again. This fungus, whose incidence is now increasing in Cuba, is the causal agent of an important disease in Africa.

Sincerely yours,

E. González y B. Martínez

Laboratorio de Micología Vegetal, Centro Nacional de Sanidad Agriopecuaria (CENSA),
San José de las Lajas, La Habana, Cuba. E-mail: [e-mail]