African mahogany (Khaya ivorensis) introduced in Brazil in recent years has been preferred to reforest devastated areas to replace Brazilian mahogany (Swietenia macrophylla) due to its high-quality timber and its high resistance to Hypsiphyla grandella, the major pest of Brazilian mahogany. Since 1999 a high incidence of target leaf spot caused by Thanatephorus cucumeris has been observed in nursery and in field, in the States of Amazonas and Pará (Brazil), causing numerous zonate lesions on mature leaves and 100% leaf fall in seedlings. Young leaves of diseased plants initially show little brown spots surrounded by a purple margin, while in mature plants the lesions are light brown exhibiting concentric rings resembling a target.
