Help Identifying Crab Apple Disease ...

[Replikant]

Can anyone nail this one? Not sure what disease I am dealing with here on my crab apple bonsai. Powdery mildew, cedar apple rust, fire blight??? Any help appreciated. Have used some foliar based systemic fungicides but none copper based. 2 applications and still the same you see below. Was thinking of partial defoliation as a last resort. I had already cut some leaves in half to allow more light in. Most of what you see is only on one side of the tree's foliage btw.

 

[Nybonsai12]

I'm sorry I don't know what you are dealing with. Just a few thoughts. Was it repotted this year? I don't think it could be a root issue but figured I'd ask. Maybe just me but all three pics kind of look different. Are you against copper based fungicides? I've had the most success clearing problems with copper.

 

[Replikant]

It was repotted this Spring in well draining mix and did well. No, not opposed to copper based just trying to find a good one locally. Probably will try one this weekend though. I was trying a milder foliar systemic but I agree that copper based may be the answer. I need to pull out the big guns before things get any worse.

 

[edprocoat]

It looks like the fire blight, especially the leaf in the last picture up in the right corner that's dark. It can be treated with vinegar and the fruit tree spray fungicide will clear it up.

ed

 

[Replikant]

I understand the fruit tree spray but how is vinegar employed? How is it applied?

 

[edprocoat]

I understand the fruit tree spray but how is vinegar employed? How is it applied?

Its half vinegar and half water, spray it on! It kills the blight - I think - by making it too acidic to live on the plant.

ed

 

[Oliver Muscio]

Wi

If it is fireblight (I'm not sure that it is) fungicides of any kind will not help--fireblight is a bacterial disease, not fungal. Treatment in fruit trees (prevention, really) is with an antibiotic such as streptomycin. I'm not sure that is still available for this purpose. Will vinegar help?--I don't know.
Oliver

 

[gergwebber]

I do not see fire blight, yet anyway. It looks more like a rust or a toxicity of some sort.

The only "control" for fire blight is to cut it out, and keep the plant healthy as possible. It could spread to near by trees, almost all Rosacea are susceptible.

 

[GrimLore]

Get Copper Fungicide - Looking very closely at the leafs I see some discoloration, some curling, and some "bumps". There are several types but they all do similar and copper treats them...

Grimmy

 

[Cadillactaste]

It was repotted this Spring in well draining mix and did well. No, not opposed to copper based just trying to find a good one locally. Probably will try one this weekend though. I was trying a milder foliar systemic but I agree that copper based may be the answer. I need to pull out the big guns before things get any worse.

You should be able to call a local nursery. I picked up some liquid copper fungicide at ours recently.

 

[Replikant]

Copper fungicide applied ... we'll see where things go from here .. 2nd application in 7 days

 

[GrimLore]

Copper fungicide applied ... we'll see where things go from here .. 2nd application in 7 days

If it rains it off before 7 days reapply. You should notice any new growth is much better as the old stuff is replaced.

Grimmy