Pathogen and pest risks to vegetatively propagated crops in humanitarian contexts: Toward a national plant health risk analysis for Cameroon and Ethiopia

Cameroon and Ethiopia face humanitarian crises that disrupt the production of key food security crops like banana and plantain, cassava, potato, and sweetpotato. In this study, we address seed degeneration in these crops, the reduction in planting material quality due to the accumulation of pathogens and pests. We consider the context of humanitarian crises, with the goal of developing an ongoing national plant health risk analysis, in this case to inform decisions about mitigating seed degeneration. We analyzed cropland density maps and applied network centrality metrics to identify locations that are candidates for disease and pest management and surveillance in Cameroon and Ethiopia. We used expert knowledge elicitation and global trade data to map pathogen and pest movement risks and characterize trade of crop-specific commodities and planting materials. We identified specific locations that may be important for pathogen and pest spread in in Cameroon and Ethiopia, given their roles in the cropland network, and the reported presence of pathogens and pests. This national plant health risk analysis can inform regional and national surveillance and management strategies and provide a baseline for more in-depth studies in Cameroon and Ethiopia. We discuss strategies for ongoing improvement of a national plant health risk analysis, to inform decision-making in the humanitarian sector for designing on-the-ground actions to avoid unintentional spread of pathogens and pests during agricultural recovery interventions.