Dead/dying robinia

[Tony Croft aka hamadryad]

The question is, what are those orange-red bumps? they resemble nectria cinnabarina but darker, and they sure are packed together tightly. in the US it is a Very weak pathogen/saprophyte, so it's likely a secondary issue.

 

if those are graft unions then the grafts failed, and i agree that is not an insurmountable barrier.

 

hate to state the obvious again treeser!

 

sometimes its better to just keep my mouth shut as its just too easy.

 

(im playing)

 

its insect eggs

Edited May 28, 2013 by Tony Croft aka hamadryad

[redmoosefaction]

Ahh mr croft! I've been waiting for you to crop up

 

What's this, a bond movie

[Tony Croft aka hamadryad]

Hi mr croft! Been waiting for you to crop up

Firstly, your post on the matter is hugely interesting! I take my hat of to you sir!

With the Frisia I have affectively pollarded it below the graft, so I will see if any of the buds down the stem developer further.

 

Any pointers as to what's got me acer!?

Best I can remember its acer palmatum

 

If I dig up to remove I will check roots.

 

 

 

Quote:

I think we can make some educated guesses. Armchair dendrology / pathology if you like.

 

 

 

We know that only the Frisia variety seems to be affected. So it seems reasonable to infer that this disorder affects Frisia because its Frisia. (Seems simple huh, but normally correlation does not mean causation.)

 

 

 

So what's different about Frisia?? As Lee's link reminds us; its a grafted variety and its got yellow foliage. It was created by cramming a bit of a naturally occuring yellow sport into the rootstock of a normal R. psuedoacacia.

 

 

 

Yellow leaves are yellow because carotenoids are reflecting more visible light than the cholorophyll which is present at lower levels than green leaves - they photosynthesise at a slower rate. Traditionally "yellow" plants / trees are considered less vigourous than their wildtype counterparts.

 

 

 

It seems reasonable to infer that less vigour means a reduced ability to compartmentalise as well as slower growth.

 

 

 

A vascular wilt fungus clogs and blocks xylem vessels as it is transported (typically from the soil) around the tree. Robinia spp. are ring porous so to begin with, any damage caused by such an agent affects a greater percentage of active vessels.

 

 

 

We can there surmise that perhaps the normal Robinia pseudoacacia might have sufficient vigour to compartmentalise any damage and even grow additional vascular tissue over a longer/earlier growing season.

 

 

 

Its interesting that the RHS info suggests that it would be a surprise that such an agent could pass through the "graft barrier". What barrier? The tissue is fused?

 

 

 

Additionally, lets not think of this disease attacking and affecting different trees. Frisia is probably a graft clone. As a clone, if one tree can be affected...

 

 

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wrong tony mate,

[Quercus-90]

Haha so it is :embarresed:!!

 

 

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