Name the fungus..

ConorDash

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Hello all,

Let’s play name the fungus, if you will please? I swear I’ve seen this in pictures on the internet before but it’s no tar spot or common black spot, it looks.... worse. It’s a Maple, Beni chidori. It appeared on random leaves, not localised or on new or old leaves. Tree is otherwise healthy, planted in akadama, watered normally.

D8C103C2-1F7A-4733-AF99-C06FADE994E1.jpeg

I’ve removed affected leaves, and, as I was due to do any way, sprayed all with fungicide tonight. It’s the turn of the Rose Clear Ultra, 3-1. Very well known spray, used by many.
I guess my concern is, 1, if it continues and spreads but 2, is it infections to other trees...

So far it’s only on leaves so hopefully this means it’s not something more serious, from the trunk or branches.

Fertiliser burn? Seems too fast if it were. I’ve not seen thiS type of issue before. It has been windy but doesn’t seem like a wind scorch.

Any ideas?
 

Johnnyd

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Freeze? Some of mine got a few hours below and the edges turned black.
 

ConorDash

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Freeze? Some of mine got a few hours below and the edges turned black.

Hmm possible although any temps below 2 or 1c I’d move it in to a shed.. and as you say I think cold affects outer edges, not inside, this seems fungal.. thanks for suggestion :)
 

River's Edge

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Hello all,

Let’s play name the fungus, if you will please? I swear I’ve seen this in pictures on the internet before but it’s no tar spot or common black spot, it looks.... worse. It’s a Maple, Beni chidori. It appeared on random leaves, not localised or on new or old leaves. Tree is otherwise healthy, planted in akadama, watered normally.

View attachment 297557

I’ve removed affected leaves, and, as I was due to do any way, sprayed all with fungicide tonight. It’s the turn of the Rose Clear Ultra, 3-1. Very well known spray, used by many.
I guess my concern is, 1, if it continues and spreads but 2, is it infections to other trees...

So far it’s only on leaves so hopefully this means it’s not something more serious, from the trunk or branches.

Fertiliser burn? Seems too fast if it were. I’ve not seen thiS type of issue before. It has been windy but doesn’t seem like a wind scorch.

Any ideas?
Did you check the underside of the leaves? This could be the result of Aphids or scale insects attacking the leaves from the underside with the damage showing on the other side. The only reason I ask is this is the time for their highest level of activity. New leaves, new shoots.
 
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I can’t help OP, sorry. But I’d like to enter a contestant if you don’t mind.
 

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River's Edge

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I can’t help OP, sorry. But I’d like to enter a contestant if you don’t mind.
Margins attacked and drying out, likely wind or heat scorch. Pot drying out too quickly between watering. Try removing affected leaves and watching water more carefully, selected a more shade location out of drying winds if possible. Monitor for a week or two.
 
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Margins attacked and drying out, likely wind or heat scorch. Pot drying out too quickly between watering. Try removing affected leaves and watching water more carefully, selected a more shade location out of drying winds if possible. Monitor for a week or two.

Thank you. I get a delta breeze off the river in the evenings but we have had a wet spring. The substrate moisture is not a problem, but I can’t rule out the wind. I investigated the garden again and noticed 2 things. The yellow edges were indeed crispy but it doesn’t always appear on the edges first, it’s spotty in the middle of some leaves.
 

River's Edge

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Thank you. I get a delta breeze off the river in the evenings but we have had a wet spring. The substrate moisture is not a problem, but I can’t rule out the wind. I investigated the garden again and noticed 2 things. The yellow edges were indeed crispy but it doesn’t always appear on the edges first, it’s spotty in the middle of some leaves.
Always possible there is more than one variable at play. Spring is a time for fungal issues particularly if it has been wet and cool! If just a few leaves than remove and monitor. If persistent show to experienced nursery in your area! Pathogens are best understood within the local climate!
 

ConorDash

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Did you check the underside of the leaves? This could be the result of Aphids or scale insects attacking the leaves from the underside with the damage showing on the other side. The only reason I ask is this is the time for their highest level of activity. New leaves, new shoots.

I did not check no, good idea. Ill have a look at it this morning, but Id have thought i would have noticed them.. Will see. Itll get pesticide spray tonight.
 

ConorDash

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Good few more.. random placement on the leaves..

Any thoughts?

C886C7FD-3538-41BA-8837-4DDF2407484F.jpegF5898D23-C2BD-4E14-AAEA-251CC132683F.jpeg33036575-E73B-491E-8E85-E49A6632B3A0.jpegF83C76B5-1269-47F1-AED1-D3D78117D414.jpeg
 

BobbyLane

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so have you ruled out scale insects??
they would look like this on the trunk and stems and be very hard to spot.
if a tree is stressed its just one of those things to check for among the usual suspects
 

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BobbyLane

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It does look like that Tom.
i would remove infected leaves and spray with diluted lime sulphur along with your fungicide.
when i use LS i dont follow any set rules, i spray at random times even after a tree is in leaf if i think there is an issue. none of that spray once every 14 days stuff.
works great for me and sorted out the anthracose i had on my big field elm.
i would also avoid wetting the leaves when watering.some trees are fine with it and others just dont like it imo.
 
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ConorDash

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so have you ruled out scale insects??
they would look like this on the trunk and stems and be very hard to spot.
if a tree is stressed its just one of those things to check for among the usual suspects

I have had a look for bugs of any kind, fairly sure there is nothing there but will look again shortly.


I did look at anthracnose, but didnt think it was.. however, my leaves are quite different to the usual big green maple leaves that these pics use, so perhaps it is same but looks slightly different.

Ive sprayed all with Rose Clear yesterday, will ensure ALL affected leaves are cut off today. I've not used lime sulphur yet, personally, although heard of it plenty. Ill be sure to get some, not necessarily for now, just because it is useful to have.
Also have Neem Oil for that purpose.
Cheers guys, will see!
 

TomB

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What seems odd to me is that the damage is in the middle of the leaves, rather than the tips which is more usual. Hence my suggestion.
Given your history with fungal issues on maples, I would 100% recommend dormant treatments (spray or dip) with lime sulphur, diluted about 20:1, next winter and spring (before the buds open). Strict hygiene, keep foliage dry, ensure good air circulation, make sure your substrate doesn't stay too wet. There does seem to be something going on in your garden, you shouldn't be seeing all these problems.
 

River's Edge

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Two steps I would take. One fact I would check out regarding lime sulphur.
One allow tree to dry out slightly between waterings, do not water foliage. Wet, high humidity conditions must be avoided. Do not keep the soil wet.
Two, if available apply systemic broad based fungicide ( thiophonate-methyl based fungicide) to be absorbed by the roots. Apply to soil.
Note: Lime sulphur is more effective as a preventative than active treatment. It is normally only applied when the trees are bare of leaves and in a vegetative state.

You may wish to rethink your substrate mix. If you live in a damp climate with wetter winters than perhaps adapt to a less retentive soil mix. I live on Vancouver Island and lengthy periods of rain in the winter and higher humidity is part of my climate. For that reason the majority of my trees are kept in inorganic mix with a maximum of 20% Akadama. When I use straight Akadama or Kanuma for specific situations they are hand watered and far less frequently than the rest of the trees. They are also sheltered from rain during winter.
There is a great explanation of Maple health concerns contained in Andrea Merriggioli's new book " Bonsai Maples"
The focus is that the majority of our issues are husbandry issues, plants suffering additional stress due to the conditions they are kept in. Also that some cultivars are very susceptible to certain fungal issues. Preventative measures are definitely required for them.
They primary culprit is soil mix and watering practices, followed by poor placement and environmental stress!
 
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BobbyLane

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What Tom said. but i always go a step further, i remember Will baddely on the old europeanbonsai forum advising spray when dormant, then in spring as buds are swelling and again when the second flush appears in summer. this eradicated a problem i had on my elm.
 

ConorDash

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What seems odd to me is that the damage is in the middle of the leaves, rather than the tips which is more usual. Hence my suggestion.
Given your history with fungal issues on maples, I would 100% recommend dormant treatments (spray or dip) with lime sulphur, diluted about 20:1, next winter and spring (before the buds open). Strict hygiene, keep foliage dry, ensure good air circulation, make sure your substrate doesn't stay too wet. There does seem to be something going on in your garden, you shouldn't be seeing all these problems.

I thought about the dormant spray last year after always hearing plenty about it but didn’t go for it. I will in future or now, as Bobby suggests. I will allow this maple to dry a bit more than others, I have been watering more frequently recently as I think I don’t water enough, as a general rule.

In terms of my practice, Tom and @River's Edge i have been actually trying with this.

So, I am not watering foliage mass, only root system (especially with maples), haven’t done so this year at all. I was going to relax that rule once leaves harden off.
I water very thoroughly with every tree, so it runs through.
They are all kept on my bench which is in basically full sun all day. It’s been terrible wind lately so they’ve moved about a bit but I’m aiming for full sun, all my trees should be fine it.

Since bud break, I’ve been following a system treatment rotation. I’ve 2 different fungicides and 3 different pesticides. I spray every 3-4 weeks, ensuring I keep rotating. I’m aiming for prevention over cure, but also ensuring trees don’t get used to the same treatment and become immune.
Most trees are in a complete inorganic mix, molar clay/cat litter. Some have small bit of bark. Others are in a more organic/inorganic mix from Kaizen. A few recently bought are in akadama, this maple is one of them.


Two steps I would take. One fact I would check out regarding lime sulphur.
One allow tree to dry out slightly between waterings, do not water foliage. Wet, high humidity conditions must be avoided. Do not keep the soil wet.
Two, if available apply systemic broad based fungicide ( thiophonate-methyl based fungicide) to be absorbed by the roots. Apply to soil.
Note: Lime sulphur is more effective as a preventative than active treatment. It is normally only applied when the trees are bare of leaves and in a vegetative state.

You may wish to rethink your substrate mix. If you live in a damp climate with wetter winters than perhaps adapt to a less retentive soil mix. I live on Vancouver Island and lengthy periods of rain in the winter and higher humidity is part of my climate. For that reason the majority of my trees are kept in inorganic mix with a maximum of 20% Akadama. When I use straight Akadama or Kanuma for specific situations they are hand watered and far less frequently than the rest of the trees. They are also sheltered from rain during winter.
There is a great explanation of Maple health concerns contained in Andrea Merriggioli's new book " Bonsai Maples"
The focus is that the majority of our issues are husbandry issues, plants suffering additional stress due to the conditions they are kept in. Also that some cultivars are very susceptible to certain fungal issues. Preventative measures are definitely required for them.
They primary culprit is soil mix and watering practices, followed by poor placement and environmental stress!

Thanks for your post, great info. I do ensure to keep foliage dry. I’ll try to keep this tree soil a bit drier, atm I’ve been watering more frequently.. so it’s not necessarily dried out before next watering. I’ve removed all the bad foliage and sprayed now. I have actually ended up spraying with same fungicide twice now in the past month, but it’s a very good one so will hope. Any other advice or am I doing the best I can with this at the moment?

we are in a fairly windy, sunny climate currently. Not raining often at all. Very windy.
The tree has also been moved to opposite side of the garden now, all alone.. about 15-20ft from others.
 
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