Bacterial burn
Bacterial blight is a bark disease caused by the bacterium Pseudomonas syringae pv. Morsprunorum . It can be found on all stone fruit cultures , but especially on plums and cherries . The infections take place in autumn. Grooved, sunken, black-red lesions (injuries) form on the bark of the trunk and branches. These tear open in April / May and there is a flow of rubber . With strong trunk infections, trees die completely.
The bacterium dies in the wood at the end of May / beginning of June and is then no longer detectable. But from the end of May, leaf infections appear with shotgun-like symptoms. The holes are oily translucent and surrounded by a yellowish ring.
In the case of cherries in particular, the pathogen penetrates the trees through leaf scars that occur when the leaves fall. Furthermore, winter cuts in the rain and frost cracks are an entry point for the pathogen.
Prevention: Carry out the winter pruning after the harvest, because the wounds heal more poorly in winter. Cut the infected branches and trunk back into the healthy wood. Tests have shown that the whitening of trunks reduces the formation of frost cracks and thus prevents trunk infections. By applying copper-containing pesticides during leaf fall, an infestation-reducing effect on Pseudomonas is achieved.
Web links
Individual evidence
- ↑ Plant protection product directory of the Federal Office for Agriculture ( Memento of the original dated August 3, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ R. Grimm & O. Cazelles: Bacterial fire of the cherry tree ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. PDF, 220 kB
