Corynespora cassiicola f. sp. lantanae: a potential biocontrol agent from Brazil for Lantana camara

Corynespora cassiicola was found for the first time in Brazil in association with Lantana camara. The fungus caused severe defoliation of plants under field conditions. A host-range test indicated that this particular isolate is highly specific to L. camara and restricted to certain lantana biotypes. The lantana-pathogenic C. cassiicola was recognized as a new forma specialis and named C. cassiicola f. sp. lantanae. The fungus sporulated abundantly in some solid substrates, particularly rice and sorghum grains and ground cassava roots. It sporulated well in vegetable–broth–agar medium when grown under continuous light for 15 days at an optimal temperature of 23 °C. Inoculated L. camara plants developed 100% disease severity and >70% defoliation when exposed to a minimum of 6-h dew period following inoculation. Even plants not exposed to dew developed a high level of disease severity 6 h after inoculation. Plants inoculated twice at 15-day intervals developed high levels of disease severity, had significant growth-reduction, and occasionally died. A phytotoxic substance was present in the filtrate from germinated conidia of the fungus. C. cassiicola f. sp. lantanae appears to have a high potential as a biocontrol agent for certain L. camara biotypes.