Managing Horse Chestnuts with Bleeding canker

[Fungus]

the alicin is for the treatment of the miner, the idea to prevent the tree from being debilitated by defoliation and able to better fend of the phythopthora. at least thats what I assumed that was the idea?

 

Yes and no. Both methods aimed at directly (spray) or indirectly (transport from roots to leaves) killing the larvae of the moth, thus implicitely enabling the tree to better defend itself against the bacteria (Pseudomonas syringae), but the second method - instead of protecting the roots - killed the already present endomycorrhizal microfungi in the soil food web with detrimental effects for the condition (water and nutrient uptake) of the tree.

[Fungus]

allicin is anti-fungal, and also anti-bacterial. The trials in the Netherlands used systemic trunk injections to control the HCBC bacteria. I believe the effect it had on leafminer was a beneficial side effect, as other elements of crushed garlic contain anti-larvicidal properties.

 

William,

The trunk injections were part of an experiment on prevention of infection (like was/is done with injecting Ulmus against Dutch elm disease) with the bacteria, not on treatment of already infected trees and the only effect documented was the side effect of withholding some of the larvae from developing and spreading.

The dripping method also was used to "treat" the roots of oaks infected with OPM with the same detrimental results for the ectomycorrhizal macrofungi associated with Quercus robur, because of the strong toxic effects of allicin, which is produced by Alliaceae to keep their territory within the soil food web free from competing mycorrhizae or mycelia of fungi and of parasitic bacteria and larvae or nematodes.

[William]

William,

The trunk injections were part of an experiment on prevention of infection (like was/is done with injecting Ulmus against Dutch elm disease) with the bacteria, not on treatment of already infected trees

 

Hi Gerrit,

 

I'm not aware of the experiments you mention, I'm only aware of the Allicin Tree Care trials that have been in the trade journals in the UK when trunk injections were used. I understand that allicin degrades very quickly in the environment and I would be suprised if it had the ability to prevented disease and have seen studies that show that it does not contribute to any aquired resistance type effect, but it is effective as a 'control' in its own right.

[Fungus]

I understand that allicin degrades very quickly in the environment and I would be suprised if it had the ability to prevented disease and have seen studies that show that it does not contribute to any aquired resistance type effect, but it is effective as a 'control' in its own right.

 

William,

Correct if introduced slowly but directly into the soil (food web), but not without having caused the death of already present endo- and/or ectomycorrhizal micro- and macrofungi first, which made the trees even more vulnerable to invasions of parasitic bacteria and/or micro- and macrofungi, because they lacked their natural root defense systems.

Edited July 9, 2011 by Fungus

[William]

William,

Correct if introduced slowly but directly into the soil (food web), but not without having caused the death of already present endo- and/or ectomycorrhizal micro- and macrofungi first, which made the trees even more vulnerable to invasions of bacteria or parasitic micro- and macrofungi.

 

Hi Gerrit,

 

I agree with you on the soil applied effect of allicin on soil fungi, after all this is what allicin has been evolved to do over thousands of years. Maybe other types of applications such as trunk injections or direct application onto cankers may have benefit for otherwise condemned trees. Also, as you have suggested, allicin may have beneficial effects on trees infected by parasitic fungi?

[Fungus]

Maybe other types of applications such as trunk injections or direct application onto cankers may have benefit for otherwise condemned trees. Also, as you have suggested, allicin may have beneficial effects on trees infected by parasitic fungi?

 

William,

I have not yet seen any research based evidence of these suggested positive effects.

[William]

William,

I have not yet seen any research based evidence of these suggested positive effects.

 

I was refering to your comment made above - you said that you have seen allicin kill 'endo- and/or ectomycorrhizal micro- and macrofungi' which suggests it kills fungi? And therefore could it not be used in an alternative way (not into the soil) to kill other types of fungi?

[Fungus]

I was refering to your comment made above - you said that you have seen allicin kill 'endo- and/or ectomycorrhizal micro- and macrofungi' which suggests it kills fungi? And therefore could it not be used in an alternative way (not into the soil) to kill other types of fungi?

 

I should have been more specific. Allicin secretion of Alliaceae serves to kill or oppress further development of the mycelia of competing symbiotic endo- or ectomycorrhizal fungi in the soil food web. The mycelia of parasitic fungi produce and use totally different toxics (antibiotics, fungicides) to defend their territories inside trees against competing fungi, which implicates, that allicin probably will have no or little effect on parasitic fungi, because they use (far) more powerful toxics, which are even capable of killing living tissue of trees defending themselves with acids, tannines and resins against their attacks.

[William]

allicin probably will have no or little effect on parasitic fungi, because they use (far) more powerful toxics, which are even capable of killing living tissue of trees defending themselves with acids, tannines and resins against their attacks.

 

I agree that this would probably be the case against these types of fungi. What do you think about allicin having any effect on other fungus like organisms such as Phytophthora, or on bacteria such as Pseudomonas? Do you think it could theoretically control these diseases in trees?

[Fungus]

I agree that this would probably be the case against these types of fungi. What do you think about allicin having any effect on other fungus like organisms such as Phytophthora, or on bacteria such as Pseudomonas? Do you think it could theoretically control these diseases in trees?

 

Because of its powerful, but rather unstable fungicide and anti-biotic properties, theoretically it could, but one would need a lot of work (and financial funding) for scientifically valid monitoring and evaluating the in vivo experiments needed to prove the supposed effects.