Alternaria spp. isolates pathogenic to sicklepod (Senna obtusifolia) were characterized based on morphological characteristics and isozyme patterns. Colonial morphology and conidial shape showed that 11 of the 13 isolates belong to A. cassiae. The other two isolates were identified as A. alternata. Isoenzyme patterns confirmed the results of morphological criteria. The occurrence of more than one species of this fungus infecting S. obtusifolia was found, widening the range of suitable pathogens to be evaluated in bioherbicide programs for sicklepod control.
