Black oozing Magnolia

[Gavski]

We have recently moved to a house that has a very big (probably old) Magnolia.

I recently noticed a black oozing substance coming from the base of the tree - see photos.

Is this a problem and what can I do about.

The tree seems fairly healthy, it flowered in spring, followed by good leaf coverage but then continued to flower all season? also there are quite a few dead branches inside of the canopy.

Advice/help appreciated.

[RobRainford]

i wouldnt say that it is P. ramorum, you may see the same symptoms, all phytophthora species give the same symptoms, to determine which is which is difficult, an ELISA field test can be used to determine whether it is phytophthora, i am unsure whether they are specific to each strain of phytophthora though.

 

You can get species specific i.e. P. alni, P. ilicis which affect alder and holly.

 

It is not a massive issue, it isnt actually a fungi, but a water mould (oomycete) and is a bacterial infection.

 

although it can cause some damage if left alone, i would certainly look to manage the magnolia, whether by giving it some nutritional aid or some pruning to remove any poor branches, however pruning a tree that could be stressed may not be beneficial.

[Tony Croft aka hamadryad]

i wouldnt say that it is P. ramorum, you may see the same symptoms, all phytophthora species give the same symptoms, to determine which is which is difficult, an ELISA field test can be used to determine whether it is phytophthora, i am unsure whether they are specific to each strain of phytophthora though.

 

You can get species specific i.e. P. alni, P. ilicis which affect alder and holly.

 

It is not a massive issue, it isnt actually a fungi, but a water mould (oomycete) and is a bacterial infection.

 

although it can cause some damage if left alone, i would certainly look to manage the magnolia, whether by giving it some nutritional aid or some pruning to remove any poor branches, however pruning a tree that could be stressed may not be beneficial.

 

[treeseer]

Hi I have just joined the site and noticed your problem with your magnolia...Almost definately Phytophora ramorum...

If the government department suspects its ramorum then it has to come down.

 

No offense meant, but this policy seems a tad extreme. "expects"?

[Fungus]

Phytophthora ... it isnt actually a fungi, but a water mould (oomycete) and is a bacterial infection.

 

Rob,

Oomycetes resemble fungi in mycelial growth and mode of nutrition, but differ from fungi, because they lack chitin in their cell walls. They are not related to bacteria, but are, together with diatoms and brown and golden algae, part of the Kingdom Stramenopila.

[Tony Croft aka hamadryad]

Rob,

Oomycetes resemble fungi in mycelial growth and mode of nutrition, but differ from fungi, because they lack chitin in their cell walls. They are not related to bacteria, but are, together with diatoms and brown and golden algae, part of the Kingdom Stramenopila.

 

I knew they was more closely related to plants than fungi, but thanks for clarifying their proper classification:thumbup1:

[treeseer]

referred to in some geneticist circles as a FLO, fungus-like-organism.

 

I knwo what Rob is talking about; signs can resemble bacterial infections.

 

Lesions can be traced, rinsed and cautrerized, to lessen inoculum.

 

Soil can be replaced and rosaceous mulch applied to retard infection.

 

Has another treatment program been suggested?

[Tony Croft aka hamadryad]

Lesions can be traced, rinsed and cautrerized, to lessen inoculum.

 

Soil can be replaced and rosaceous mulch applied to retard infection.

 

Has another treatment program been suggested?

 

lessen inoculum? I was under the impression most trees whilst can be infected did not act as sources?

[sloth]

Soil can be replaced and rosaceous mulch applied to retard infection.

 

Why rosaceous?

[Fungus]

1. Lesions can be traced, rinsed and cautrerized, to lessen inoculum.

2. Has another treatment program been suggested?

 

1. How ? I thought Phytophthora was a soil oomycete/pathogen invading the tree by its roots.

2. Any thoughts or suggestions on other treatment programs ?

[ScottF]

1. How ? I thought Phytophthora was a soil oomycete/pathogen invading the tree by its roots.

2. Any thoughts or suggestions on other treatment programs ?

 

Perhaps look to chronic soil waterlogging/poor drainage and treat that if applicable? Try to achieve relatively dry local conditions either by intercepting water draining to the tree (if it's in a depression), or hollow-tine aerate and fill with sharp sand. Given the genus, combine with a low pH mulch (leaf mould, not too deep.

 

Wait and see...