Ceratocystis cacaofunesta is an ascomycete fungus that causes a wilt disease in cacao trees. It has led to significant economic losses in Latin America.
Once considered to be a form of Ceratocystis fimbriata,[1] the fungus was described as a new species in 2005.[2] The specific epithet "cacaofunesta" means "cacao-killing".[2] Two closely related sublineages exist within this species, one centered in western Ecuador and the other containing isolates from Brazil, Colombia and Costa Rica.[2]
The disease known as "Ceratocystis wilt of cacao" (or "Mal de machete") is a serious disease of the cocoa tree (Theobroma cacao) in Latin America.[3] The fungus is indigenous to Central and South America.[4]
This fungus is able to penetrate cacao trees through stem wounds that are caused either by insects or through infected cutting tools.[4] Wounds made by harvesting pods, removing stem sprouts or weeding may become infected.[1] The disease is a systemic infection that damages the entire plant.[4] The fungus enters its host through the xylem, causing a deep stain leading to the obstruction of water and nutrient transport.[4] It moves systemically through the plant.[3] Eventually, the plant turns yellow and then brown, leading to wilting and the sudden death of the tree.[4]
The disease has been of major importance in Costa Rica, Trinidad and Tobago, Ecuador, parts of Colombia and Venezuela.[1] In the 1990s, C. cacaofunesta was introduced to the southern region of Bahia, which is the largest Brazilian cacao-producing state.[4] This disease is responsible for reductions in the cacao population in plantation areas, which has resulted in great economic losses in the affected regions.[4] The fungus has killed as many as half of the trees in some locations.[1]