Managing Armillaria

[treeseer]

http://www.tcia.org/Digital_Magazine/PDFs/lowres/TCI_Mag_May10LR.pdf

 

Page 22: Trees infected with Armillaria fungus can be treated by exposure and by inoculation with beneficial antagonists to that pathogen. This research, conducted in the United Kingdom and with the lead author from the United Kingdom, proves the effectiveness of exposing the infected area and treating with beneficial microorganisms.

 

In addition, several studies in the forestry, phytopathology and ecology literature demonstrate the effectiveness of these treatments. Therefore, it seems that condemning trees in urban areas based on rhizomorphs without considering these simple therapeutic treatments may be needlessly costing those communities irreplaceable arboreal resources.

[David Humphries]

Thanks for posting up the article Guy. I don't get to read up on the American Arb perspective as often as perhaps I should.

 

I attended a briefing at Kew on monday (which was predominantly about the chemical mangement of Oak processionary moth) but Glyn Percival was there talking about a few bits and pieces, but alas not the Trichodema/Armillaria issue.

 

He really looks like a man who thrives/excels on the research front. Clever & fortunate man.

 

Here he is brandishing his hydrostatic trident

 

 

 

.

 

 

.

[David Humphries]

Looks to be some text missing between the end of p22 & the start of p23 ?

 

"These rhizomorphs function to.............................major roots, are generally removed from site to reduce the level of the Armillaria fungus."

 

 

Have you got access to the original Guy ?

 

 

 

 

.

[James]

David, I think it's '...carry water and nutrients to the mycelium

under the bark being attacked. These rhizomorphs extend back to previously rotted

roots and stumps, leaves or even the soil.

Control: Existing Techniques

In landscape situations, all sources of

infection such as infected stumps and...'

 

Interesting article that, thanks for posting it Treeseer.

[treeseer]

Thanks James for reading between the images; David, you must have mis-scrolled there.

 

That is the UK perspective, as related in the US. That mag has good stuff now and then, aside from my rubbish.

 

The UK lab's research is much more interesting than their US counterpart's; the selection of topics reflects a much higher awareness. Not only more open minds, but more full minds! They do seem to understand how trees work, and seek to put pathogens in their place.

 

Whatever that trident does, I don't want it done to me!

Edited May 19, 2012 by treeseer

[David Humphries]

David, I think it's '...carry water and nutrients to the mycelium

under the bark being attacked. These rhizomorphs extend back to previously rotted

roots and stumps, leaves or even the soil.

Control: Existing Techniques

In landscape situations, all sources of

infection such as infected stumps and...'

.

 

Thanks James for reading between the images; David, you must have mis-scrolled there!

 

 

 

Doh !

 

 

 

 

.

[David Humphries]

have never come across this before ...............

 

"Soil sterilization with steam (6kg pressure for

30 minutes at 120 C) is used in some

European countries, but this treatment has

to be applied annually and suffers from the

drawback that this process kills all soil

borne organisms as well as Armillaria"

 

Poor soil

 

 

 

.

[Fungus]

1. Trees infected with Armillaria fungus can be treated by exposure and by inoculation with beneficial antagonists to that pathogen. This research, conducted in the United Kingdom and with the lead author from the United Kingdom, proves the effectiveness of exposing the infected area and treating with beneficial microorganisms.

2. In addition, several studies in the forestry, phytopathology and ecology literature demonstrate the effectiveness of these treatments.

3. Therefore, it seems that condemning trees in urban areas based on rhizomorphs without considering these simple therapeutic treatments may be needlessly costing those communities irreplaceable arboreal resources.

 

1."the potential of Trichoderma (Trianum, a Dutch product for instance used for Fusarium control in beans) against A. mellea remains unknown" ... "the use of root invigoration in combination with Trichoderma may provide a useful cultural/bio-control combination for long term A. mellea control." (How, when, where and by whom is this monitored and tested ?) ... "Results of our experiments should also be interpreted with some degree of caution when adapting research from grapes and strawberries to large trees with respect to structural aspects."

2. How can several studies in the forestry, phytopathology and ecology literature demonstrate the effectiveness of these treatments if "the potential of Trichoderma against A. mellea remains unknown" and the "results of our experiments should also be interpreted with some degree of caution when adapting research from grapes and strawberries to large trees with respect to structural aspects" ? Besides, old wine in new bottles considering the extensive research on the effects of Trichoderma (and Phlebiopsis gigantea) on Heterobasidion annosum and the lack of proof for the long term effectiveness of the treatment.

3. Again jumping to conclusions on an unproven assumption ?

 

Apart from the above, the following remarks and questions arise :

- What about Armillaria ostoyae, the dominant species on oaks and coniferous trees ?

- What about the effects of acidification and nitrification causing the massive outbreak of Armillaria and can these effects be overcome or neutralised by root invigoration and the introduction of Trianum ?

- What about the effects of tree root invigoration on root protecting and defending mycorrhizae ?

- Strawberries and grapes are endomycorrhizal, a lot of the affected tree species are ectomycorrhizal.

- Why introduce Trianum into the soil food webs of trees if "Trichoderma is a genus of fungi that is present in all soils" and also in trees in combination with plaques of Armillaria ostoyae that does not seem to "suffer" from the presence of Trichoderma at all (see photo) ?

 

The photo shows the inside of a felled oak that was brown rotted by Laetiporus sulphureus and white rotted by Armillaria ostoyae with the presence of the anamorph Trichoderma viride (of Hypocrea rufa) "feeding on" the plaques of the Armillaria without damaging the melanin covered wood degrading hyphae.

---

[treeseer]

"the use of root invigoration in combination with Trichoderma may provide a useful cultural/bio-control combination for long term A. mellea control." (How, when, where and by whom is this monitored and tested ?) ...

 

& You'll have to ask the authors about that one. We won't argue about how long "long" is. As in other Tree health care typically, it is part of a suite of treatments, not standalone.

 

"Results of our experiments should also be interpreted with some degree of caution when adapting research from grapes and strawberries to large trees with respect to structural aspects."

 

& This is standard cya language; trees are large objects... The amount of soil removed is highly unlikely to destabilize a mature oak--is this a serious question?

 

2. How can several studies in the forestry, phytopathology and ecology literature demonstrate the effectiveness of these treatments if "the potential of Trichoderma against A. mellea remains unknown"

 

& It's the combination of treatments they were testing, and they were judging by the results.

 

In the references are actual tests and the "results of our experiments should also be interpreted with some degree of caution when adapting research from grapes and strawberries to large trees with respect to structural aspects" ?

 

& Again grasping at the straw of the structural non-issue?

 

Besides, old wine in new bottles considering the extensive research on the effects of Trichoderma (and Phlebiopsis gigantea) on Heterobasidion annosum and the lack of proof for the long term effectiveness of the treatment.

 

& No one's guaranteeing forever--a short-term benefit is still a benefit, and may allow other therapies, such as soil work to mitigate acidification and nitrification, take hold. For trunks and buttresses, decay fungi can and should be resisted. Trees can wall off some wood-destroying fungi, inexorably and indefinitely, indicating immortality.

 

3. Again jumping to conclusions on an unproven assumption ?

 

& Condemning mature urban oaks based on nearby rhizomorphs sounds more like jumping to conclusions on an unproven assumption!

 

Apart from the above, the following remarks and questions arise :

- What about the effects of acidification and nitrification causing the massive outbreak of Armillaria and can these effects be overcome or neutralised by root invigoration and the introduction of Trianum ?

 

& Acidification is global and gradual. Cow crap has been spread on fields since the dawn of civilization. The problems you cite are (somewhat) reversible, at least proven treatable. The authors note at the end that these two therapies are part of a program of care.

 

- What about the effects of tree root invigoration on root protecting and defending mycorrhizae ?

 

& Other studies show improvement in tree health and growth. An inventory over time would be interesting to see, true. The populations might shift, and while this might upset the tssm/tsse applecart in one view, populations of microbes can adjust, influenced by the dominant organism, the tree.

 

- Strawberries and grapes are endomycorrhizal, a lot of the affected tree species are ectomycorrhizal.

 

& True, and the forestry references deal with trees: Redfern notes that "Infection by A. mellea in Britain occurs by means of rhizomorphs; *the transfer of mycelium at root contacts is probably not important as a means of spread. ... Quercus robur and Fagus sylvatica were more resistant* than all the conifers except A. grandis. Soil type influenced disease development and the proportion of trees infected was higher in an acidic sand soil than in an alkaline clay soil." So yes reducing acidification and nitrification should be part of the work--and soil replacement and modificiation does that.

 

& Baumgartner confirms that spread was not significant in that study. If other observations indicate spread between oaks may be faster, is this based on a controlled experiment in which some trees got this proven treatment, and a control group did not? Or was it by passive observation, like the link previously put up about foresters in Arkansas inventorying species of fungi--outside the context of treatment, and this forum's title, "Tree health care".

 

- Why introduce Trianum into the soil food webs of trees if "Trichoderma is a genus of fungi that is present in all soils" and also in trees in combination with plaques of Armillaria ostoyae that does not seem to "suffer" from the presence of Trichoderma at all?

 

& That looks like an issue of timing and quantity. In tree health care, efforts are made to decrease the potential of pathogens. If Armillaria-infected tissue and soil is removed before inoculation, an introduced inoculant can more likely gain the upper hand. The picture shows Armillaria going full force, and a few specks of Trichoderma on top, which is the completely opposite scenario.

 

Earlier, when i described this treatment anecdotally, you did not speak kindly of it, and asked for supporting research. I just ran across it, so there it is. Can you prove it wrong? Talk to the tree health care experts in Reading.

All we are saying, is give trees a chance. Before trees of value are condemned, these treatments, in concert with other care such as soil modification, should in all good conscience be considered.

 

It's good chatting with you, as always.

Edited May 20, 2012 by treeseer

[Fungus]

1. The amount of soil removed is highly unlikely to destabilize a mature oak -- is this a serious question ?

Ad 1. It was not the effect of the amount of soil removed on the stability of the plants that was the subject of the in vitro research -- is this a serious answer ?

 

2. It's the combination of treatments they were testing, and they were judging by the results.

Ad 2. Testing on grapes and strawberries and with results assuming, i.e. not proving a positive short or long term effect on trees.

 

3. Trees can wall off some wood-destroying fungi, inexorably and indefinitely, indicating immortality.

Ad 3. Repeating your "mission statement" doesn't prove anything.

 

4. Condemning mature urban oaks based on nearby rhizomorphs sounds more like jumping to conclusions on an unproven assumption !

Ad 4. Who says I've ever condemned a tree on the presence of nearby rhizomorphs or on the mere presence of rhizomorphs alone ? Speaking of jumping to conclusions !

 

5. Acidification is global and gradual. Cow crap has been spread on fields since the dawn of civilization. The problems you cite are (somewhat) reversible, at least proven treatable. Other studies show improvement in tree health and growth. An inventory over time would be interesting to see, true. The populations might shift, and while this might upset the tssm/tsse applecart in one view, populations of microbes can adjust, influenced by the dominant organism, the tree ... the proportion of trees infected was higher in an acidic sand soil than in an alkaline clay soil." So yes reducing acidification and nitrification should be part of the work--and soil replacement and modificiation does that.

Ad 5. Acidification from cow crap ? I thought it came from brown coal fired powerplants or heavy industry and cars.

Massive nitrification comes from three to four storey pig and chicken "farms" with over 15.000 animals per stable and from overmanuring (ammonia) of grasslands and maize fields, i.e. not from extensive agriculture using cow pads. So how do you suppose to treat, reverse, overcome or neutralize the effects of these nitrification levels ? By soil replacement in all woodlands, parks and roadside verges of The Netherlands and the western parts of Germany ?

And you obviously still don't understand the essence and importance of the tree species specific soil food web if you think microbes can take over the basic functions of mycorrhizal fungi.

 

6. That looks like an issue of timing and quantity. In tree health care, efforts are made to decrease the potential of pathogens. If Armillaria-infected tissue and soil is removed before inoculation, an introduced inoculant can more likely gain the upper hand.

The picture shows Armillaria going full force, and a few specks of Trichoderma on top, which is the completely opposite scenario.

Ad 6. All assumptions for which there is no proof. How do you assess the quantity and effectiveness of several different Trichoderma species that are already present in the soil before deciding to introduce an artificially produced Trichoderma ?

And can you judge from the quantity and size of the anamorphs in the picture how much material of the Armillaria melanin plaques was invaded and degraded by the mycelium of the Trichoderma ?

 

7. this treatment ... Can you prove it wrong ?

Ad 7. The question is not whether I can prove it wrong, it's whether you can prove it right.