Trident maple leaf opening problem.

[hisseibonsai]

Hello everyone,
There is such a problem with Trident leaves. The leaves cannot fully open. What is this? The leaf tips are turning black.
The leaves are like a round ball. They do not open fully.

 

[BonsaiMatt]

Looks a lot like the tree in this video. I think he found a cure.

 

[Notsureaboutplantnames]

Do you know the name of the cultivar Eric mentioned that has upward curled margins?
This one is growing in my area and I am stumped. (Its not drought - every year for 20yrs)

 

[Time Wizard]

Looks a lot like the tree in this video. I think he found a cure.

That's the same video I was going to post. Unfortunately I don't think that is a cure so much as semi-frequent treatment.

 

[RaginCajun]

Yeah there’s nothing you can do. I’ve heard of folks planting the trees in the ground for a couple years and they “cure themselves” but soon as they’re stressed(potting) it comes right back. I haven’t had a tree survive it so far. It’s Tridents or some other maple every time. I haven’t seen the same disease or fungus or whatever it is on any other species in my collection.

 

[Vali]

I was dealing with a disease with those signs a few years ago on a linden. I managed to control it with bordeaux mixture. It stopped the disease but it reapeared after a few weeks so I had to respray it periodically. I managed to cure it completely only when I started to treat it with lime sulphur. I used it as a winter wash and I think I reapplied it probably twice in that growing period, when it reappeared. I haven't had any problems since. In fact, I very rarely have fungal problems with my trees after I started using lime sulphur.

 

[Wires_Guy_wires]

I think @hisseibonsai is not telling us the whole story.

We have no information other than a description. And I honestly believe this is a human-caused issue.
Please tell us more about how the plant was treated in the past months.

 

[hisseibonsai]

Looks a lot like the tree in this video. I think he found a cure.

Thank you @BonsaiMatt
I will watch the videos and start applying with active ingredient fungicide.

 

[hisseibonsai]

Do you know the name of the cultivar Eric mentioned that has upward curled margins?
This one is growing in my area and I am stumped. (Its not drought - every year for 20yrs)

View attachment 589078

The maple tree Eric is talking about is Acer Buergeranum Naruto. I think it's a different variety...

 

[hisseibonsai]

I think @hisseibonsai is not telling us the whole story.

We have no information other than a description. And I honestly believe this is a human-caused issue.
Please tell us more about how the plant was treated in the past months.

@Wires_Guy_wires ,

I bought this Kaede 2 years ago. It was imported from the Netherlands to Türkiye. It was autumn when I bought it, the tips of the leaves were black. I didn't pay much attention when I bought it. Because winter was coming and the leaves would fall.
I changed the pot in March 2024. There were many roots inside the pot. There was almost no soil (akadama) left. While pruning the roots, I noticed this. They had re-added the tree in the small pot to a larger pot without cutting any roots. I couldn't believe my eyes when I came to the roots of the small pot. Because there was only kanuma soil. There was also a lot of osmocot fertilizer mixed in the kanuma. I cleaned the roots completely and washed them with water.
In 2024, the leaves started to turn burnt and black again. Although I used copper-based fungicides, the disease did not go away. I also applied fungicides with Metalaxyl and phosphorous acid active ingredients. However, I did not get any results. I wanted to share this situation with you in early spring this year.

 

[Wires_Guy_wires]

Thanks for writing that out! Merhaba!
Are you close to the sea by any chance?

What I'm seeing is a very specific issue regarding the incisions in the foliage. The three points all have a V intersection where they meet the leaf, and something is damaging that specific part. Because leaf cells are made in a certain order: first the meristem differentiates into a round leaf, then abscisic acid 'cuts' the V-shapes making three points out of a circle, then the cells expand and the leaf unfolds, then the cells expand further and solidify. Something is going wrong either in the abscisic acid cut, OR the cut sites die and dry up, causing the expansion to behave like an umbrella.
See it like an umbrella, or even better: a parachute. Cut the ropes off of a parachute, and you're left with a circle. The dried part of the foliage right now acts like the rope. Since it seems to happen before the cells in the leaf expand and reach their full size, I'm thinking something is damaging them after full leaf emergence.

This parachuting can happen in a couple of instances:
- When the evaporation rate is too low.
- When air flow is too high.
- When the nutrients are only nitrogen.
- Salt stress.
- Mite damage.
- Leaf sucking insects like aphids on the underside of the leaf.


I'm thinking two options: salt stress, or some kind of mite.
Mites especially are hugely understudied in science. So much understudied that some whole cultivars have later been attributed to mite damage instead of genetic changes. Treating with a miticide before a new flush comes out, might solve the problem for now. I don't know what miticides would be available in your area.

Since emerging foliage looks clean and has no problems, something happens after they emerged. Those edges is where the most water evaporates, and if you are close to the sea, that is the area where salt will build up and burn the foliage. Depending on where you are, your water might be an issue too. Chlorine and chloramine can damage foliage too, leading to similar problems, in a sense that looks somewhat like salt stress.

I hope my deduction can help you figure out what's wrong!

 

[Notsureaboutplantnames]

Expanding leaves require proper humidity and high amounts of Calcium to build walls. The translocation of Ca only moves with water evaporating from the leaves.

Water stress induced Ca deficiency is very common in hydroponic lettuce production and can be solved by increasing air flow (pulling water to the leaf tips with Ca in the water).

You could try applying a foliar spray of Ca. But it is only temporary fix and not the solution.

Not sure if you have the resources or the interest but a leaf sample sent to a soil lab can determine the amount of Ca but,,,, I dont know if there is any baseline recommendations for this species.

 

[Notsureaboutplantnames]

The maple tree Eric is talking about is Acer Buergeranum Naruto. I think it's a different variety...

Thanks, you are correct, its not the same one.