An international study has identified the mix of soilborne pathogens behind root diseases in Ethiopia’s faba bean crops, marking a step forward in the fight for food security.

Researchers discovered the scale and diversity of root rot disease affecting Ethiopia’s most important legume crop, which provides a roadmap for managing this agricultural challenge.

Led by the Ethiopian Institute of Agricultural Research, researchers from The University of Western Australia’s School of Agriculture and Environment, UWA Institute of Agriculture, the Tamworth Agricultural Institute, the South Australian Research and Development Institute, and the International Center for Agricultural Research in the Dry Areas in Morocco collaborated on the study published in Pathogens.

Soilborne diseases are a leading cause of crop loss in Ethiopian faba bean production, with farmers losing between 45 per cent and 70 per cent of their harvest to root rot each season.

Researchers assessed root disease and collected soil samples from 150 faba bean fields across seven major growing regions that were analysed using advanced DNA testing to identify and quantify 29 different pests and pathogens.

The study revealed widespread pathogens including some reported for the first time in Ethiopia. In addition to root rot pathogens, the study found high levels of foliar diseases as well as the root-lesion nematode, which is a serious threat to plant health.

Professor Martin Barbetti, from UWA’s School of Agriculture and Environment and The UWA Institute of Agriculture said efforts to identify the cause of root disease in faba bean have relied heavily on traditional observation and culture methods, which often missed or misidentified pathogens. 

“This research used modern molecular tools to deliver a clear picture of which pathogens are present and how they occur in combinations that make diseases harder to treat,” Professor Barbetti said.
 
“The ability to reliably and accurately define the pathogens involved in soilborne disease complexes is foundational to being able to predict and manage them.”

The research confirms chemical treatments such as fungicides are unlikely to be effective when multiple pathogens coexist in the soil. 

The findings call for integrated disease management approaches including screening for resistant and tolerant faba bean varieties and tailored farming practices adapted to local soil and environmental conditions. 

The research was supported by the Australian Government through Australian Centre for International Agricultural Research (ACIAR).