Infection of mungbean seed by the charcoal rot pathogen Macrophomina phaseolina

IntroductionCharcoal rot, caused by the fungus Macrophomina phaseolina is a widespread and sometimes serious disease of most summer field crops, including mungbean (Vigna radiata), in eastern Australia.The disease is most commonly known as causing a dry blight (also known as charcoal rot or ashy stem blight) of stems when plants are subject to moisture and/or heat stress after flowering. Affected plants usually die prematurely.M. phaseolina can also cause a soft, wet rot of mungbean sprouts, when the fungus grows from infected seeds during the sprouting process. The presence of the pathogen in seed poses a serious risk to some overseas sprouting seed markets. Studies were undertaken to determine the method of infection of mungbean seed by Macrophomina phaseolina prior to investigating possible control measures.