Armillaria investigation

[treeseer]

I surrender, I don't know what I am talking about.

 

When it comes to predictions about tree biomechanics, does anybody?

 

My white flag is waving as well.

[David Humphries]

.......I still carry in my head the extreme zero tolerance treatments suggested by Strouts in "Diagnosis of ill health in tree". I am watching in my local park the trees near a recent A.m victim, the nearest one has extensive dieback and won't recover. The next one has generally declining vigour and the third has isolated dieback or poor vigour. Beyond that the trees are OK. Soil conditions poor (grass, compaction, waterlogging, leaves cleared). An inevitable slow-motion domino effect.

 

We had three young limes succumb to Armillaria at the same time over a relatively short period 4 years ago.

 

Their decline was rapid & aggresive, but there have been no further out breaks of fruiting or decline of the immediately surrounding trees in the following years.

 

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[David Humphries]

I've also noted occasions where trees with Armillaria have lead to a wind throw situation but the tree (pear in this instance) continues to produce leaves, flowers & fruit (albeit in a rather more relaxed position)

 

 

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[David Humphries]

............the fruit bodies are consitant with what I would expect of Armillaria mellea as opposed to Armillaria gallica.

 

Well, there's been an interesting development regarding the Id of the fruitbodies, I perhaps should have waited to post this thread until confirmation, but a good acquaintance of mine (Andy Overall) who's a field mycologist, has had a look under the scopes at the micro features of a couple of specimens from the lime site.

 

The two species vary in some of their macro features but are pretty similar with regards to their size, colour, stipe & gills.

 

The absolute way to tell them apart is via the basidia clamps, or lack of (A. mellea has none)

 

The basidia are the long cucumber like structures where the spore develope and are then released from.

 

The following images show;

1st shot, the clamp(s) attached to the base of the basidia (lhs of the blue line points to one)

 

2nd, the spores

 

3rd, the scale cells and spores.

 

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[David Humphries]

............A. melea is considered a more aggressive pathogen than the more benign A. gallica species.

 

 

this information perhaps buys this particular tree more time, before any further works require proscribing.

 

 

 

 

 

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[David Humphries]

Not related to the original trees of this thread but I was searching for previous threads concerning Armillaria gallica and this one came up.

 

Here are the fruiting bodies of A. gallica and their associated rhizomorphs at the base of this old oak.

 

 

 

Not particularly concerned with this situation as the tree is in good health (though hosting Fistulina and Griffola) but as stated earlier in this thread (and other resources) A. gallica is largely saprophytic in nature

 

 

 

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Edited November 4, 2016 by David Humphries

[David Humphries]

Armillaria mellea on lime

 

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[Kveldssanger]

That's a lovely showing there!

[David Humphries]

Third year of mass fruiting on this 'pollard' that I know of.

 

 

 

 

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[jomoco]

Are you familiar with Plant Growth Promoting Rhizobacteria David?

 

Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective

 

Jomoco