DRAFT FOR STAKEHOLDER COMMENT BY 4TH SEPTEMBER 2025

Fusarium foetens is a wilt pathogen of begonias (Begonia), especially Hiemalis group begonias (Begonia x hiemalis) that are a hybrid between B. socotrana and B. tuberhybrida. These begonias are grown primarily as potted flowering plants for both indoor and outdoor use in spring and summer. The pathogen is not present in Great Britain but has been intercepted on numerous occasions. It is currently unregulated, though statutory action is taken on findings on Begonia plants for planting as a precaution. 

This rapid PRA shows: That Fusarium foetens is a wilt pathogen of a subset of begonia species and rooibos (Aspalathus linearis). The pathogen causes a lethal wilt disease of Hiemalis begonia and is found primarily in commercial glasshouse facilities where these plants are raised from plugs to flowering. Plants infected with F. foetens are unable to be sold due to the severity of the disease. Not all begonia hybrids are susceptible to the disease and most outdoor varieties of begonia, tuberous begonia and seedling begonias, are not susceptible. Fusarium foetens has also been identified as the causal agent of a wilt disease of rooibos in a limited growing region of South Africa, though this disease is not as severe as the wilt caused on begonias and is likely to co-occur with other wilt pathogens. There are no other reliable reports of this pathogen infecting other host plant species.

The PRA concluded that it was very unlikely with medium confidence that this pathogen would establish outdoors. This pathogen primarily impacts large commercial growers of indoor Begonia and Begonia hybrids, that regularly import plantlets on plugs from the EU. The potential economic impact of this pathogen was rated as small with high confidence. Risks associated with the disease caused by F. foetens can be managed by proper monitoring and removal of plants showing symptoms in plant nurseries before sale. These inspections are already done regularly by growers to monitor and control a number of severe wilt diseases. Therefore, the recommendation is not to regulate Fusarium foetens.