Fungal resistance and age

[ajm55555]

I have a question that popped up from my experiences with Japanese maples. I always had young plants and a few fungal issues that probably let to the death of some of them.
I was wondering if older plants are more resistant or not?
If yes, can you define old in this context?
Happy and safe Spring!

 

[penumbra]

Older means more resistant in my experience in my climate, though your climate is much hotter and more humid to boot. I have about 40 maples, most are just part of a collection and not deemed to be bonsai. I have only lost one when it was still quite young. The first year I often get a little leafspot on new trees added to my collection, but then they generally get over it and grow well for me as the get a little older. The one I lost was loose in the pot and I think it had root damage.
So old in my case is not a term used though older is. And older is a year later.

 

[ajm55555]

The one I lost was loose in the pot and I think it had root damage

Thank you penumbra! Do you generally seal root cuts when you prune your maples? Even the small ones?

 

[penumbra]

Do you generally seal root cuts when you prune your maples?

I have never sealed a root cut.

 

[ajm55555]

I have never sealed a root cut.

Isn't sealing a good protection against a disease like Verticillium Wilt?

 

[ajm55555]

From Wikipedia: "When roots of a host crop come near the resting structure (about 2mm),[5] root exudate promotes germination and the fungi grows out of the structure and toward the plant. Being a vascular wilt, it will try to get to the vascular system on the inside of the plant, and therefore must enter the plant. Natural root wounds are the easiest way to enter, and these wounds occur naturally, even in healthy plants because of soil abrasion on roots. Verticillium has also been observed entering roots directly, but these infections rarely make it to the vascular system, especially those that enter through root hairs."

 

[ajm55555]

OK, I hijacked my own thread. I'm still interested to know if anyone has experience that there is less probability of fungal infection the older the tree is

 

[penumbra]

Isn't sealing a good protection against a disease like Verticillium Wilt?

In 62 years of moving trees it has not been an issue.

 

[sorce]

I don't think age has to do with it other than resistant plants CAN get old.

No resistance no life.

That's why people shouldn't try and save seedlings, or anything, if it's weak.

Let it die!

Sorce

 

[bonhe]

OK, I hijacked my own thread. I'm still interested to know if anyone has experience that there is less probability of fungal infection the older the tree is

It is actually very good question. I don’t know about the tree, but for the human, either end of the ages: too young or too old , one is easily susceptible to infection due to the weak immunity system! I guess we can translate this to the tree. Any kind of assaults to the tree such as pruning, root cutting, change living environment can reduce the immune response of the tree.
Thụ Thoại

 

[Wires_Guy_wires]

I'll put my knowledge into understandable words, since this is a complex topic.
Younger plants should have a stronger immune response, because everything is closer together and there's less sap flowing overall. So any infection will be noticed by the entire plant. Signalling is stronger.

I agree with @sorce on this one: only resistant plants survive, the others die. Saving young plants with antibiotics could equal an antibiotic treatment as a life sentence.

Some resistance can build up over time, or weaken over time. This is a complex epigenetic play, that sometimes takes multiple generations.
The more complex a micro/eco-system is, the higher the chance of infection, but also the higher the chance of a counter-organism being present. All microbes make antibiotics, some work like a systemic, others as a topical. So some older plants host more diverse microbes than younger ones.. In general.. It could also be the other way around. As younger plants are better at signalling, which in turn can attract or activate counter-microbes.

Some plants can compartmentalize tissue as a response, and the damage is aesthetic at most, others can't compartmentalize and get infected all the way.

Some environments have salt sprays that prevent infections, others have strong winds to do so, some others have drought and blasts of UV rays. Other environments suck so much that only fungi thrive.

So fungal infections.. They happen or they don't. If it's your fault, treat them. If it's common and also not your fault (species, location, natural presence of hosts), then just don't keep the tree. Fighting uphill battles is only fun if you can win. If you keep losing, then what's the point of fighting? It doesn't prove a thing. Also, if the infection isn't killed entirely, it can become resistant to your antibiotic.. When that happens there's a huge risk to all the plants that get infected due to human mistakes; treating those has no effect anymore.
MRSA is a prime example of an organism that did just that. I expect more of those bacteria to pop up now that half the world can get pneumonia and will be treated with antibiotics at some point in the near future.

 

[ajm55555]

Very interesting @Wires_Guy_wires. Thanks!

 

[ajm55555]

That's why people shouldn't try and save seedlings, or anything, if it's weak.

Let natural selection do its thing!
I agree @sorce. I hope you're all holed up and safe, as anyone else.

 

[ysrgrathe]

Thank you penumbra! Do you generally seal root cuts when you prune your maples? Even the small ones?

I was taught not to. When we seal branches it's primarily to keep the wound edge moist to prevent dieback. There is no need for that in a saturated rootball. And typical sealants wouldn't work anyway in that environment.

 

[sorce]

Let natural selection do its thing!
I agree @sorce. I hope you're all holed up and safe, as anyone else.

I just went to the depot.

Got me a 12er and a boxwood!

Waiting for someone to zombie out and attack me, run!

No shit though i got brain shanks around the yard!

Sorce

 

[ajm55555]

@sorce :-D
Suddenly the whole world is in a zombie apocalypse video game.

Let's hope people behave and we go back to our fine dust layered skies.

 

[Leo in N E Illinois]

Dormant verticillium sclerotia in the soil is the reason we tend to use "virgin" materials for our potting media. Soil born diseased are the reason to NOT REUSE previously used media. Heat sterilizing media is a good idea if you are able. Not everybody can do so.

I am not paranoid about reusing soil, but I do generally use "virgin" materials for my potting mixes for trees I really do not want to loose. Growing out seedlings, etc, I am not as careful, but any trees with several years of work in them are worth using "clean" potting media.

 

[bonhe]

Younger plants should have a stronger immune response, because everything is closer together and there's less sap flowing overall. So any infection will be noticed by the entire plant. Signalling is stronger.

The more complex a micro/eco-system is, the higher the chance of infection, but also the higher the chance of a counter-organism being present. All microbes make antibiotics, some work like a systemic, others as a topical. So some older plants host more diverse microbes than younger ones.. In general.. It could also be the other way around. As younger plants are better at signalling, which in turn can attract or activate counter-microbes

Thanks for interesting ìnfo.
What is about the role of cutin in disease fighting?
Thụ Thoại

 

[Wires_Guy_wires]

Thanks for interesting ìnfo.
What is about the role of cutin in disease fighting?
Thụ Thoại

Cutin is part of the cuticle, I believe it helps to keep water out (and keep water in, reduce water loss from evaporation) and lets sunlight in. Most bacteria and all fungi need water to live, and if the outside of a plant is somewhat water repellent, then bacteria can't get in unless they cross this barrier. Due to cutin being a fatty acid, it can also become a bit fluid with some warmth. Most bacterial and fungal spores cannot germinate if they are surrounded by fatty acids: water can't get in if cutin encapsules them.
Some microbes can break it down though.
Think of it as a waxed car: if dirt and particles land on it, and it rains, the rain washes off the dirt. Everything that keeps sticking to the car, is covered in the wax itself. For spores of bacteria and fungi, this 'being trapped' part means that they get a daily dose of UV and sun radiation, all day. This doesn't kill all of them, but at least a large part.

Are you satisfied with that answer?