The management of water hyacinth is possible through physical, chemical or biological means. Mechanical removal and use of herbicides, however, have been found to be either inadequate or too expensive especially in large tracts. In recent years, therefore, the focus shifted to natural enemies of water hyacinth including plant pathogens. Since the main means of propagation of the weed is through offshoots, water hyacinth is thought to be a good candidate for biological control. In particular, the success of the host-specific Cercospora rodmanii in controlling water hyacinth greatly stimulated interest in the management of the weed using fungal pathogens (Conway, 1976; Conway and Freeman, 1977). The Abbott Laboratories of USA developed an experimental formulation of C. rodmanii, named ABG-5003, against E. crassipes (Te Beest, 1991).