Fig Rust Caused by Cerotelium fici: Past, Present and Future

Fig rust is one of the serious fungal diseases caused by Cerotelium fici which causes great loss to the overall growth and yield of the plant. This disease is generally characterized by pale reddish-brown to reddish-brown angular leaf spots, typically found on the adaxial surfaces of the leaves, whereas the corresponding abaxial surface of the same leaves was covered with a lot of orange rust pustules. With the progression of this rust disease, angular spots fused to form necrotic patches whereas, leaf edges curled upward. Premature abscission of leaves takes place, leaving bare branches and unripe fruits. This disease showed its global distribution in tropical and subtropical areas, however, the highest distribution was found in the African continent (18 countries) followed by Asia (14 countries), North & South America (10 countries each), Europe (8 countries) and 7 countries in the Oceanian continent. Apart from the rust pathogen Cerotelium fici, the Phakospora nishidana was also reported to cause fig rust which has created confusion on the identity of C. fici as a fig rust pathogen. This suggests a need to re-examine all specimens of fig rust at the global scale, based on morphological and modern DNA-based methods so that the taxonomic ambiguities on fig rust pathogens can be resolved and suitable control methods can be implemented to avoid serious crop and yield loss.