Beech, Armillaria?

[Fungus]

1. Nectria infections are not associated with black oozing.

Well then North American mycologists need to identify the cause of those lesions

2. Has drying out or otherwise treating Arm. infections ever been formally studied over there?

3. Arborists manage trees and their associates in the landscape, not the forest. If installing a new associate helps the tree, that's in the realm of arboriculture. If forest ecologists will not intervene to that extent, that seems to be a limitation they have in prescribing care for landscape trees.

4. Has anyone looked -formally, anecdotally, in any way, at alternative methods for managing Arm. that may be due to nitrification

 

1. What about the cause of the black oozing then ?

2. No, your "methods" are not part of Dutch arborists' practice. Besides how do you think this can be done effectively if we are talking about thousands of beeches and oaks infected with parasitic Armillaria species of which oaks are also living under the ever increasing heavy burden of attacks of insects such as OPM or other moths (defoliation) and oak leave mould also associated with nitrification and both beech and oak suffer from drought ? Ever heard of a combination of factors or multicausality making the in vitro "one on one" research you wish for impossible ?

3. Over 90 % of my research on parasitic Armillaria infections on beech and oak is on roadside trees and/or trees in lanes in urban and rural environments and on extensively managed estates, but - of course- assessed and monitored by a mycologist and forest ecologist specializing in the tree species specific ecosystems and life cycles of indigenous trees including the role of ectomycorrhizal symbionts in the defensive system of the trees. If arborists can not assess trees from that perspective, that seems to be a limitation they have in prescribing care for landscape trees.

4. If you were at least a bit familiar with the causes and effects of nitrification on the European continent you would not ask this question.

Edited April 30, 2012 by Fungus

[Fungus]

Has drying out or otherwise treating Arm. infections ever been formally studied over there?

 

Could you cite scientific articles on the effectiveness of your methods of drying out and otherwise treating Armillaria infections on white oaks from the US and Canada ?

And are you familiar with Kelley, Fierke & Stephen (2009) Identification and distribution of Armillaria species associated with an oak decline events in the Arkansas Ozarks (For. Path. 39, 397-404) and Brazee & Wick (2009) Armillaria species distribution on symptomatic hosts in nortern hardwood and mixed oak forests in western Massachusetts (Forest Ecology and Management 258, 1605-1612) ?

[Amelanchier]

How close is this tree to other trees and if they are within 5 to 10 meters apart, are their root systems connected or grafted ?

If so, I would advise to stop further spreading of rhizomorphs of the Armillaria by completely removing the tree and carefully removing its roots, removing 10 cubical metres of soil and filling the hole with "healthy" soil before replanting or wait for 5 to 10 years before planting a tree at all.

 

This is an interesting approach, could you flesh it out a bit more?

 

I presume you don't mean remove all roots? How do you deal with those that are grafted?! How did you arrive at 10 cubic metres? Doesn't the specification to remove all roots (even just the significant ones over 25mm diameter) neccessarily involve the removal of more than 10 cubic metres of soil (excavations of approx 4.0m x 4.0m x 0.6m for example)?

 

Anyhow, isn't Armillaria endemic to most soils inhabited by trees? Isn't it useful recycler in such situations?

 

I suspect it is far easier to manage infected / declining trees than to manage host soils.

Edited May 1, 2012 by Amelanchier

[HCR]

That seems an extremely expensive way of dealing with the issue and at quite a high environmental cost too. I can't see many people paying to excavate old root-pates.

[Fungus]

1. I presume you don't mean remove all roots? How do you deal with those that are grafted?!

2. How did you arrive at 10 cubic metres? Doesn't the specification to remove all roots (even just the significant ones over 25mm diameter) neccessarily involve the removal of more than 10 cubic metres of soil (excavations of approx 4.0m x 4.0m x 0.6m for example)?

3. Anyhow, isn't Armillaria endemic to most soils inhabited by trees?

4. Isn't it useful recycler in such situations?

5. I suspect it is far easier to manage infected/declining trees than to manage host soils.

 

Tony,

1. If possible, we remove all the major roots. And if the neighbouring trees in a row are so close that most of the major roots mix or graft with the infected roots, we also remove both neighbouring trees as a preventive measure.

2. It's a rough estimate from practice that is altered if circumstances call for it. With deep rooters it goes deeper than 0.6 m, with shallow rooters it stretches further than 4 m. In road side verges it can be 3.0 m x 5.0 m.

3. It often is, but it's not activated until circumstances change dramatically (air and water pollution, drought, years in a row of complete defoliage by insects, compaction, pavement alterations, road salt, cable work) and the damaged roots loose their protection by mycorrhizae as a result of this.

4. In forests, it's not primarely a recycler, but a parasite accelerating the death of a tree that has become a parasite of its own tree species specific ecosystem. Armillaria doesn't contribute much to the recycling process in forests, it is done by lots of other macrofungi, that decompose the wood in a succession of saprotrophic macrofungi more or less exclusively associated with the tree species involved.

5. Not with the thousands of infected beeches and oaks in roadside verges and lanes in urban and rural environments with far from complete tree species specific ecosystems and soil food webs to adequately "feed" and protect them. We often even have to choose to fell and remove entire lanes or rows of roadside trees and wait for replanting for five to ten years.

Within the rural community where I live, we have over sixty thousand 80-100 years old road side oaks, that are not only suffering from Armillaria and other fungal pathogens, but also from complete defoliage by OPM and other moths.

Also see my beech and honey fungus thread, my Quercus robur and Armillaria ostoyae thread and my album on rhizomorphs of Armillaria.

[Amelanchier]

Thanks Gerrit. I thought there might be more to it!

[Pat Ferrett]

Hi lads! I had a passer by ask for my comments on this beech.

My first thought was some kind of damage caused buy us humans but according to the owner it has'nt been exposed to any ill treatment in the 10 years he has owned the property.

 

Closer inspection shows whats left of what I think is Armilaria fb ?

Seems the cambium has tried to calouse and failed a few years back.

The owner is very keen to keep the old girl going,

 

Your thoughts please

[Fungus]

My first thought was some kind of damage caused buy us humans but according to the owner it has'nt been exposed to any ill treatment in the 10 years he has owned the property.

Closer inspection shows whats left of what I think is Armilaria fb ? Seems the cambium has tried to calouse and failed a few years back.

 

This looks like a combination of sun scald after (too) heavily pruning followed by the typical necrosis of the cambium and shedding of the bark because of an infection with Armillaria mellea.

[Pat Ferrett]

Thanks Gerrit!

Sun scald was my first thought but he assures me nothing in the garden has changed in the last 10 years

 

I asked about bonfires to which he admited to having a few in the past, shame if that is the case because the chap seems to have a real respect and love for the tree.

[Fungus]

Sun scald was my first thought but he assures me nothing in the garden has changed in the last 10 years

 

So the fierce reduction of the crown was done more than 10 years ago ?