Bleeding Canker
This blight disease has been found mainly on Horse Chestnut trees and in severe cases can lead to death. It was earlier thought to be a symptom of Phytophthora fungal infections, but the bacterium Pseudomonas syringae pv aesculi has been identified as the causal agent.
On affected trees sap can be seen oozing from the bark and running down the trunk. The bark becomes cracked and distorted, and on smaller trees complete girdling leads to death. If the weeping sap is removed and the cankers pared away they may dry up and heal.
A new treatment called Conquer is being launched for aboriculturalists to use. It is prepared from garlic, Allium sativum and is injected via a series of plug holes around the tree. It takes about a year for the tree to recover.
Other bleeding cankers caused by Phytophthora fungi can be found in other tree species, especially P. cambivora and P. citricola. Another, P. alni affects Alder trees. The spores are carried in water and resting spores can be found in soil.
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