Ceratocystis platani is an important pathogen of plane trees. The pathogen is already present in Europe and, despite current EU wide legislation designed to limit its further spread, the pathogen is still spreading in France and other southern member states. Although it is moderately likely that the pathogen could enter the UK, the likelihood of establishment is assessed as very uncertain because, although hosts are widespread and the known climatic responses suggest that the climate is suitable, since its arrival 70 years ago the pathogen has spread widely in southern Europe but has never been reliably confirmed north of a latitude approximating to Geneva.

If the pathogen establishes, large economic impacts may occur. Felling, removal and destruction of infested material would be very costly. Biosecurity measures during clean up operations to prevent further dispersal of the pathogen would need to be stringent and therefore add to the cost. Plane trees are a very common urban tree and if the disease becomes widespread, several major UK cities would lose a considerable proportion of their trees from parks, roadsides and squares. This could affect the character of certain cities and ultimately have adverse affects on tourism and access to green spaces for the residents. No fully effective chemical or biocontrol options currently exist and although resistant Platanus genotypes are available, it would take several years/decades for any affected habitats to recover. 

The Plant Health (England) (Amendment) Order 2013, which came into force in January 2013 strengthened existing EU measures to limit the spread of this pathogen through the introduction of statutory notifications requirements for all imports of Platanus (Plane), along with several other genera of trees. A major uncertainty is the risk that the pathogen could be introduced via asymptomatic host planting material and associated soil / growing media. Although not all imported material can be checked, the notification requirements enable further evaluation of this risk through the development of a surveillance strategy, enabling targeted inspection of the highest risk imported planting material i.e. trees imported from areas where the disease is known to occur. Trees showing damage or suspicious symptoms would be submitted for more detailed laboratory examination and testing for the presence of the pathogen.