Help id issue with japanese maple

[leandroaveiro]

Hi, I have two japanese maples. One of them started showing these gray patches on some of the leaves. Not sure if this could be a sign of over or under watering or maybe a fungus infection. A quick google search suggested powdery mildew but I am not 100% sure.

The other japanese maple is completely fine. They are both cuttings from the same tree. They are placed on the same location and they are watered usually at the same time and frequency.

Thanks!

 

[HorseloverFat]

Hmm... some of that looks.. someWHAT identifiable.. but it also looks like there MAY be more than one “issue”...

If I was to GUESS..

I’d say it APPEARS, To me, like some fungal infection (one of the more common landscape ones) ON TOP of stereotypical leaf stress...The kind newly clipped and propagated cuttings get on their old leaves as the new roots “take over” from the reserves... then the roots take over and start drawing in landscape fungus or overwatering-induced pathogens, cause... well.. it’s EXCITING when you make roots, I get it

When were the cuttings taken?

 

[Forsoothe!]

I don't see any grey. All I see is the artifact dead portions of leaves, without an interim stage of disease. Assuming a fungus or disease of any kind is not productive. What % of leaves have this condition? Are they predominately outer, older leaves, or newer leaves, or some of each, or on one side of the tree, or scattered in no discernible pattern?

 

[leandroaveiro]

When were the cuttings taken?

I don't know. I got these maples from Bill Valavanis introductory course earlier this spring. I believe he mentioned these are maybe 4 or 5 year olds.

I don't see any grey. All I see is the artifact dead portions of leaves, without an interim stage of disease. Assuming a fungus or disease of any kind is not productive. What % of leaves have this condition? Are they predominately outer, older leaves, or newer leaves, or some of each, or on one side of the tree, or scattered in no discernible pattern?

Most of the larger leaves are presenting the same symptom (90%+). The newest leaves coming out do not show anything. I don't see a specific pattern regarding being the outer or inner leaves, or from one side or the other. It's throughout the tree.

Thanks for the help!

 

[Forsoothe!]

I wouldn't rule out mechanical damage from something, maybe wind whipped leaves, wind-blown chemical sprays, maybe falling down?

 

[leandroaveiro]

I wouldn't rule out mechanical damage from something, maybe wind whipped leaves, wind-blown chemical sprays, maybe falling down?

My back yard is pretty open, so they do get their good share of wind, but so do all my other trees in the same place.
Yeah, it seems to not affect the tree too much. It's growing and new leaves are coming out.

If decide to, just in case, make a light application of a general fungicide without the tree actually having any fungus, do you guys think it could damage the tree?
I hear a lot of people spray preemptively, so I guess I should be OK, no?

 

[Forsoothe!]

To each, their own. I don't like to spray because there are side effects. I do use systemics preemptively.