Maple and Liquid Amber Fungal infection?

[Dustbunny]

Hi all,

I have maple and liquid amber seedlings that are 2 years old and most had their first repot and prune this year.
They've ended up with their leaves curling, some going black. (They also have a little leaf scorch from very strong winds a few days ago)
They still seem to be growing, maybe slowed a little.
I've been very careful with watering, but I'm still pretty new to bonsai so totally could have done any amount of things wrong
I sprayed them with Yates rose gun and it doesn't appear to have made a difference.

I have a few maple seedlings, some of the ones that weren't pruned are fine (not all), some pruned ones didn't survive repotting, the rest have this problem.
I also have 2 Japanese maples, one is fine, the other has just a bit of leaf curling in one spot, but isn't getting worse.

I found a thread from 2015 called 'Trident woes..,' many other people appeared to have the same problem, but there wasn't a conclusive answer in the thread.. ideas floated were fungal or thrips.

Just wondering if anyone has any ideas?

Thank you very much!

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[shibui]

There have been lots of diagnoses of this problem, usually based on the fact that the owner treated for a particular problem and the trees recovered.
I have had similar symptoms of distorted spring leaves on some of my trident maples but have not treated them with either pesticide or fungicide. Those trees have recovered without any treatment at all leading me to assume that whatever the problem is it is seasonal and transitory so my advice is to wait it out and see what happens.

I do note that most of your pots are in saucers. Some maples are susceptible to fungal infection through the roots when roots are too wet through winter. That has killed some trees here but others recovered when I put the pots up on a mesh bench so the potting mix dried out better. Cold and wet is not a good combination, especially for trees that have been root pruned.

Fingers crossed that your trees will get through this too.

[Dustbunny]

Thank you so much for your time and knowledge!
That's encouraging to know, fingers crossed they make it!

I'm also not happy with the tray arrangement. But a family member insists on it... I've been thinking if I elevate them on some kind of mount in the tray that might help, so they're not sitting in the actual water?

On a side note, would I be correct in saying my seedlings are trident maples?
All these seeds blew into our yard a couple of years back, and I've never been able to locate the parent tree.
But looking at other's tridents, they look exactly the same to me.

[shibui]

On a side note, would I be correct in saying my seedlings are trident maples?
All these seeds blew into our yard a couple of years back, and I've never been able to locate the parent tree.
But looking at other's tridents, they look exactly the same to me.

They do look like tridents but it is just a little too early to be sure. A few trees have very similar leaves when young. For the moment I would proceed on the assumption they are tridents. In urban areas it can be harder to track down a parent but maple seeds rarely travel more than a few hundred metres, usually much less.

I'm also not happy with the tray arrangement. But a family member insists on it... I've been thinking if I elevate them on some kind of mount in the tray that might help, so they're not sitting in the actual water?

Trays can be good to protect the floor from spills and we do need to keep significant others somewhat happy. Try filling the trays with gravel (easy to obtain and effective) or find some other way to keep the base of the pot above water level - small tile or similar under each leg?- or adjust water frequency so the soil is not constantly wet.
I use gravel filled trays to maintain moisture and humidity for my smallest pots through summer. Works well but not so much when the base of pots are submerged for part of the day.

[Dustbunny]

Just an update on this issue. I came across a youtuber who had what looks to be the same, or very similar problem. He got his trident maple lab tested and had success with 2 specific fungicides recommended by pathologists.
Here are the links:

https://youtu.be/PUs9u_9Wk6A
https://youtu.be/fEi7Pji_34w

I'm not sure if his simply recovered by the next year or if the fungicides helped. Also not sure if we can get them in Australia.

As for mine this year, I tried putting a layer of charcoal from the BBQ over the surface of the soil and saw some improvement for a couple of months. They then got a bit worse again.
In the second half of the growing season some improved quite a lot again, others didn't.
But they all continued growing.

I really hope they'll wake up again I'm spring with no problems