On 2 April 2008 the Commission published its report on a survey into the incidence of horse chestnut trees displaying symptoms of a new disease in Great Britain, Pseudomonas syringae pathovar aesculi, referred to as Horse Chestnut Bleeding Canker. Horse chestnut trees have for many years been affected by two other fungal organisms, Phytophthora citricola and P. cactorum which has not given cause for concern but in the last four of five years FC scientists have been noticing that many specimens sampled did not reveal presence of either Phytophthora and have subsequently isolated a bacterium Pseudomonas syringae pv. aesculi, which originates in the Himalayas. A nationwide-survey was carried out in 2007 to try to understand better the incidence and spread of this disease.
The information that we've obtained from these surveys gives us a scientifically sound picture of the extent of the symptoms of the problem, and a basis upon which we can make decisions about what further research is needed to help us learn more about the level of risk from the disease and develop appropriate management advice for tree owners.