N	Risk mitigation measure	Effect on the pest	Evaluation and uncertainties
1	Registration of production sites	Yes	Although the pathogen is not regulated, the risk mitigation measure could have some effects in reducing the likelihood of presence of the pathogen on the commodity. Uncertainties: – Whether disease symptoms on Acer are recognisable.
2	Physical separation	No	Not relevant.
3	Certified plant material	Yes	The risk mitigation measure could have some effects in reducing the likelihood of presence of the pathogen on the commodity. Uncertainties: – Whether disease symptoms on Acer are recognisable.
4	Growing media	Yes	As the pathogen can survive in the soil for long time, this measure, in particular using heat‐treated growing media, could be effective in reducing the likelihood of introduction of the pathogen into the nurseries. Uncertainties: – None.
5	Surveillance, monitoring and sampling	Yes	Although the pathogen is not regulated, the risk mitigation measure could have some effects in reducing the likelihood of presence of the pathogen on the commodity. Uncertainties: – Whether disease symptoms on Acer are recognisable.
6	Hygiene measures	No	Not relevant. Uncertainties: – Whether the pathogen could infect through pruning wounds thereby making effective the disinfection of pruning tools.
7	Removal of infested plant material	Yes	This measure could have some effect. Uncertainties: – Whether disease symptoms on Acer are recognisable.
8	Irrigation water	Yes	Overhead irrigation could favour foliar infections and spread of the pathogen by water splash. Uncertainties: – None.
9	Application of pest control products	Yes	Some fungicides could reduce the likelihood of the infection by the pathogen. Uncertainties: – No specific information on the fungicides used. – The level of efficacy of fungicides in reducing infection of C. castaneicola.
10	Measures against soil pests	No	Not relevant.
11	Inspections and management of plants before export	Yes	Although the pathogen is not regulated, the risk mitigation measure could have some effects in reducing the likelihood of presence of the pathogen on the commodity. Uncertainties: – Whether disease symptoms on Acer are recognisable.
12	Separation during transport to the destination	No	Not relevant.