Please help may have a pest on a Japanese Maple

[Gino]

Hi guys,
Am new to bonsai, have been at it for just under a year and my first bonsai seems to be in distress it is a Japanese maple and all was well all foliage came out wonderfully green but about half way through they started to turn browny red and disfigured can anyone shed light on the problem and possibly a solution attached are photos, thank you in advance

Gino

[Jamie]

might be a pest, thrips maybe, this can be fixed with confidor.

otherwise it could also be windburn or overwatering/underwatering.

someone else might be able to shed more light on this for ya.


jamie

[jabbado]

Hey guys, I'm interested to know what's causing this as well. I have a japanese maple with the exact same symptoms as the OP's. It was a very healthy nursery stock which was growing great in it's original pot. But after repotting into a terracotta pot the leaves started coming out like in the photo. Practically all the top growth is like this. Some of the newer lower leaves are almost normal. It's been like this for several weeks and I've tried adjusting the water schedule to see if it's under/over watering causing it but nothing seems to help. I can't find any pests and after some reading am starting to think it's a fungal problem, maybe phytophthora (root rot). I have some systemic fungicide here I might try since nothing else has helped. Unless someone can suggest another likely cause for us.

Dave.

[sreeve]

I also have teh same problem and I recall another posting about problems with Japanese Maples this year. I cant remember who posted it. I think it may have been either Brett or Ken?

Whoever it was, is this the same type of problem that you were referring to?
Regards
Steve

[Joel]

Im calling it leafburn/windburn on young leaves. The burn causes dead patches and therefore parts of the leaves dont receive enough water/nutrients through the veins in the leaves, causing retarded growth to those areas, producing oddly shapped small leaves with dead patches, just like you have shown. Just a theory!

However, there is an unusual fungal disease affecting maples this year. I talked to a plant pathologist who told me he has received a large amount of maple samples (particularly bonsai) that have had this fungus present. Just a warning, there is something out there. If you think your tree is infected, talk to a local bonsai nursery. If they cant help you, get some professional help. Those in Sydney can get a test done for about $75 from the Royal Botanic Gardens Sydney. A bit steep, but probably less than your maples are worth.....

JayC

[Jamie]

i keep coming back to this thread looking at the leaf, it is definately possibly a fungal infection, but i keep leaning to wid/leaf burn and a watering problem, i had the same issue just recently with a trident, i found small bugs on it aswell which could of been causing troubles, but i think that was due to the tree being stressed before hand from wind problems, as it was growing strong and i defoliated to do some wiring, then new leaves come through and i had this problem, so it come down to stressed tree from defoliation-new growth getting hit by some wind-bugs-removal of the new growth again after a bug spray, now the new growth popping out is coming through nice and strong, so i know what i described was several problems but i honestly think that it was wind that was causing the biggest problem to begin with.

just my thoughts on it.


jamie

[kcpoole]

Im calling it leafburn/windburn on young leaves. The burn causes dead patches and therefore parts of the leaves dont receive enough water/nutrients through the veins in the leaves, causing retarded growth to those areas, producing oddly shapped small leaves with dead patches, just like you have shown. Just a theory!

However, there is an unusual fungal disease affecting maples this year. I talked to a plant pathologist who told me he has received a large amount of maple samples (particularly bonsai) that have had this fungus present. Just a warning, there is something out there. If you think your tree is infected, talk to a local bonsai nursery. If they cant help you, get some professional help. Those in Sydney can get a test done for about $75 from the Royal Botanic Gardens Sydney. A bit steep, but probably less than your maples are worth.....

JayC

Hey JayC do you know what the treatment for this is?
I have lost at least 2 maples to it, 1 Banksia, I think 1 JBP this week, and some other misc juveniles earlier:-(

Ken

[Joel]

Sorry Ken.

I believe one person brought a whole heap in to get the disease i.d. and the ute-load of trees eventually died. Unfortunately i missed some of a meeting at work when this was discussed. I have a couple of weeks off work, then i will try and find out for you. Please remind me if i don't get back to you then!

In the meantime, i suggest filling a spray bottle with methylated spirits (diluted to aprox. %70 works well) and spray ALL tools before moving from tree to tree, and after every cut made to dead or diseased wood. One down side of your recycling watering method is that any fungal spores will get spread to all trees. The only other thing i can suggest is to keep your plants as healthy as possible, as weak plants are far more susceptible to attack.

Good luck everybody!

JayC

[jabbado]

I don't think it's windburn/water issues in my case. I did suspect that at first as it began with the mature leaves drying and curling. But the leaves are still coming out deformed from the newer growth. As my brother who is a vineyard assistant said, it looks just like grapevines when they get accidental herbicide overspray. The shoots are deformed and weak. When this first occured it was putting out heaps of new healthy looking branches and leaves (I had pruned the trunk), but most of them ended up this strange vertical growth with comparatively long internodes. Then most of the deformed leaves drop before getting to any reasonable size. New buds are forming but they seem reluctant to open, except for some of the lower branches.

I really want to repot it so I can also inspect the roots (for rot etc) but have been waiting to see if it got a bit more vigor first. Should I just do it? It doesn't look like it's improving at all.

[Gino]

Hi all,
let me start by thanking you all for the prompt replies, So far so good I have dropped watering down as the maple is in a slightly larger pot than it really needs at the moment and the over watering seemed really possible, i was just not aware that was physically possible i also gave it a complete trim of all leaves and now seems to be coming back greener and stronger than ever will keep you posted as they kind of went funny after a few weeks of being fully grown last time. once again thank you so much

Gino

[jabbado]

Gino, have you checked the roots? It turned out my tree only had a couple of live roots left. I still don't know if it's root rot caused by overwatering, or the tree dried out too much when we had a heat wave a while back. Either way the tree is pretty much done for