Two horse chestnut trees (right & fourth from right) in a row of five infected by the bacteria Pseudomonas syringae pv. aesculi

- Image ID: C50WK7
Tony Cunningham / Alamy Stock Photo
Image ID: C50WK7
Investigations in the UK and the Netherlands have indicated that the bacterium Pseudomonas syringae pv. aesculi is causing bleeding canker on horse chestnut trees. The infection kills the inner bark and outer layers of wood and leads to water and nutrient transport problems If it spreads all round the trunk the tree dies. For a while it was thought that the fungus-like micro-organism Phytophthora was the cause of this problem. Two trees in this row of otherwise healthy trees along the Kornewal in the small town of Buren in the Netherlands have been infected by the bacterium Pseudomonas syringae pv. aesculi. These are the tree to the left of the red tower in the background and the fourth one. This latter tree is the most obviously affected. These trees will be cut down in the summer of 2011 as they are hazardous.
Location: Kornewal, Buren, Gelderland, The Netherlands, Benelux, Europe