Ceratocystis platani - Canker stain of Plane

A fungal pathogen that causes a canker stain of plane trees, which leads to rapid decline and death.

Introduced to the south of France from the USA in the 1940's

Now found in Europe across France, Italy, Switzerland, Greece and Albania.

Currently considered not to be in the UK, and is the subject of an ongoing survey of Plane populations by the Forestry Commission and the London Tree Officers Association.

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Ceratocystis platani is a wound parasite that requires an open wound for infection either above ground on the trunk/major branches or below ground via root grafting.

It has no known natural vector.

The above image shows bark having being scraped to show the transition between dead and live parts of the tree and the associated canker staining.

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Pruning is the most common form of transmitting the disease within urban tree populations.

Poor (or lack of) biosecurity by Arborists working on canker stain trees, enables the pathogen to be spread by infected sawdust, wood and tools.

In Italy there are strict controls in place for those working on affected trees.

I recently witnessed this control during a dismantling operation of an infected tree in Padua, northern Italy.

Sheeting is placed under the tree to contain as much sawdust and woody debris as possible and the tree was rigged down to control the risk of damage and infection to neighbouring trees.

The arisings are contained and transported off site then burnt to destroy the infected material.

The tools are cleaned and isolated during movement between sites.

This leads to an increased cost in time and expense but is considered to be the best way to manage the spread of the disease

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The pathogen spreads rapidly through the tree so it's important to identify it via inspection as early as possible and then to have the tree(s) removed.

Symptoms to look for are;

Desiccation of leaves (which remain in the tree)

Partial canopy death associated with the vascular dysfunction below.

Transitional trunk death shown by dead bark adjacent to live bark with epicormic growth

Staining under the bark.

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Symptoms of other similar decline in Planes can be due to poisoning from disgruntled property owners (as in below)

These trees were drilled and poisoned.

Also road salt can lead to similar decline and death.

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Confirmation of the disease can be carried out by sampling core material.

Incubation

then identification of the perithecia (fruiting body), conidia and hyphae under microscope.

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Good work David, you provide more public information about plant health issues than anyone else.

Keep up the good work.

Good work David, you provide more public information about plant health issues than anyone else.

Keep up the good work.

Ta,

part of the reason of the workshop I attended was to disseminate the Information as widely as possible.

12 of us went across to Italy last weekend and spent a packed three days out in the field, in seminar and in the lab so that we can use the skills out during inspection (specifically for Ceratocystis) but also to share the knowledge with Arborists potentially working on infected trees both here in the uk and across on the continent, also Tree Officers/Tree Managers.

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How long is the incubation period? Any plans for an article in the Arb mag?

That's the one doing for the planes on the canal du midi isnt it?