Mycosphaerella leaf spot diseases of bananas : present status and outlook

By the end of the 1980s, black leaf streak disease caused by Mycosphaerella fijiensis was present in all continents where bananas or plantains were grown, although distribution in some regions was limited to a few countries. In this presentation, the spread of the disease during the 1990s in several countries and regions, and the important socio-economic consequences are discussed. From 1990 to 1999, new records of black leaf streak disease were reported from six countries in Africa, eight in Asia, eight in Latin America and the Caribbean, and one from Australasia/Oceania. M. fijiensis has also spread within countries to ecological niches that were previously occupied by M. musicola, the causal agent of Sigatoka disease, thus threatening the survival of this pathogen. This presentation also discusses the methods, developed in the last decade, to identify the species of Mycosphaerella that cause leaf spot diseases in banana.The methods were used to confirm the synonymy of M. fijiensis var. difformis and M. fijiensis, and have provided the opportunity to study the genetic diversity of pathogen populations among isolates from different geographical regions. Resumen Propagación, detección e impacto de la Sigatoka negra y otras enfermedades foliares causadas por Mycosphaerella de bananos en la década de los 90 Al finales de la década de los 80, la Sigatoka negra, causada por Mycosphaerella fijiensis, ya se encontraba presente en todos los continentes donde se cultivan bananos y plátanos, pero su distribución en algunas regiones estaba limitada a unos pocos países. En esta presentación, se discutirá brevemente la propagación de la enfermedad durante los 90 abarcando varios países y regiones, y su impacto socioeconómico. De 1990 a 1999, se reportaron nuevos registros de la enfermedad desde seis países en Africa, ocho en Asia, ocho en América Latina y el Caribe, y solo un informe de un país en Australasia/Oceania. M. fijiensis también ha estado progresando en los países para llegar a los nichos ecológicos que anteriormente estaban ocupados solo por 21 Session 1 R.A. Romero Chiquita Brands, San José, Costa Rica MyLsd 17x24 25/06/03 15:15 Page 21