Sick Arakawa

[Rivian]

I thought the sickly leaves could be handled by better soil and fertilizer, but then I took a closer look at the bark. Ive been aware of something going on there for a while but thought it might be a weird thing arakawa does when forming rough bark.
The discolored area is spreading and now cracking a bit. None of my other maples have this I believe. I rooted an airlayer and some cuttings from this plant last year and everything died over the Winter/early Spring. Dont know if related.
What do?

 

[rodeolthr]

This looks similar to pseudomonas. Possibly entered through cuts during winter when it's floating about. Someone with more knowledge correct me.

 

[rockm]

This might also be verticillium wilt. It's a fungal disease that attacks plants vascular system and kills off branches and even trunks.

Symptoms:

"Verticillium wilt appears on Japanese maples as wilted, stunted or light-colored leaves, leaf scorch, slowed growth and eventually dieback of entire shoots and branches. Individual branches or portions of the Japanese maple's canopy appear wilted and die at time."

The disease is becoming more common in nursery trees kept close together, so if this tree is near others, you're risking spread if that's what's going on. It can kill off a section in a day or two. There is no real treatment that will get rid of it, unfortunately. The fungus leaves tell-tale dark and black stains inside branches

Verticillium Wilt on Japanese Maples

Japanese maples are susceptible to the fungal disease verticillium wilt, which leaves...

homeguides.sfgate.com

 

[Bavarian Raven]

Looks like wilt to me. Sadly.

 

[Rivian]

I cut off the top portion in poor condition and then checked the wood on it and I couldnt see any discoloration. The black was only on the very outside of the phloem or bark I guess. On the top there were some largely dead sections though (light brown) that only had a live vein remaining
I think I might have gotten it already infected, but who knows. Just because leaves lose color doesnt mean it has to be verticillium, right? Ive had discoloration on regular JM and on orange dream too. In the homeguides site they say to plant resistant cultivars against verticillium, but I dont know of any.
I guess I'll throw the arakawa away. Unfortunate

 

[rockm]

I cut off the top portion in poor condition and then checked the wood on it and I couldnt see any discoloration. The black was only on the very outside of the phloem or bark I guess. On the top there were some largely dead sections though (light brown) that only had a live vein remaining
I think I might have gotten it already infected, but who knows. Just because leaves lose color doesnt mean it has to be verticillium, right? Ive had discoloration on regular JM and on orange dream too. In the homeguides site they say to plant resistant cultivars against verticillium, but I dont know of any.
I guess I'll throw the arakawa away. Unfortunate

whatever tool you used to cut the trunk back, disinfect it, wipe down with alcohol, or disinfectant spray, let it dry on it's own. You can spread stuff like this with tools, as well as physical contact.

Hard to tell what infected it, but it looks pretty virulent. Get it out of your collection NOW. Also disinfect the pot it was in before re-using.

Was this plant kept on the ground? If so, move all your other plants up off the ground.

 

[Rivian]

Theyre all standing on a granite DIY bench. In the first pic, you can see my other maples right next to it lol. The pot is plastic, I will just throw the whole thing away as one. In the trash.
Maybe I should also mention Im pretty darn sure my Bi Hoo and sango kaku got pseudomonas last year. Red twig group, its to be expected. Theyve already been discarded, as I always say, I dont run a hospital. They only had the black though, not the cracks and weird grey discoloration

 

[dbonsaiw]

I always have a bottle of rubbing alcohol on my work bench. We work too hard for too long on these little twigs to contaminate our trees with dirty tools.