Jump to content

Log in or register to remove this advert

Chalara fraxinea - Generic thread


David Humphries
 Share

Recommended Posts

On 22/06/2019 at 13:47, EdwardC said:

On a more positive note, it doesn't appear to infect olives.

That's not a positive note. Olives are akin to engorged ticks and should be incinerated for biosecurity reasons. I have no doubt that Xylella fastidosa was knocked up by someone who knew what they were doing, for the greater public benefit ? 

Link to comment
Share on other sites

Log in or register to remove this advert

16 hours ago, Adam M said:

That's not a positive note. Olives are akin to engorged ticks and should be incinerated for biosecurity reasons. I have no doubt that Xylella fastidosa was knocked up by someone who knew what they were doing, for the greater public benefit ? 

Heathen ! ?

Link to comment
Share on other sites

This may not be the precise best place to post this. However I've spotted an Ash nearby to my home that is exhibiting some significant foliage stress. I've taken a sample and it does not seem to be emenating from the leaf veins as per ADB rather from the leaf margin. 

I'm interested in what this could be for obvious reasons. The tree stands imediatley next to another which is not showing these signs of foliage stress. 

My next thought was verticillium wilt but it doesnt appear to match images I can see from a quick Google. 

All thoughts and theories welcomed. 

O

IMG_20190816_202534.jpegIMG_20190816_202544.jpeg1566145649959.jpeg

Link to comment
Share on other sites

  • 2 weeks later...

IMG_4539.jpgIMG_4540.jpg

Yesterday I had to fell a reasonable sized Ash tree that was showing advanced signs of ADB. I had heard that the disease shortens the wood fibres and makes them weaker. When I looked at the hinge I would normally expect on a healthy Ash to see menacing looking pointy needles of fibre sticking up but on this one the fibres were indeed shorter and blunter. I certainly wouldn’t want to fell one with a significant lean in the wrong direction.

  • Like 5
Link to comment
Share on other sites

3 hours ago, jonnygurkha said:

IMG_4539.jpgIMG_4540.jpg

Yesterday I had to fell a reasonable sized Ash tree that was showing advanced signs of ADB. I had heard that the disease shortens the wood fibres and makes them weaker. When I looked at the hinge I would normally expect on a healthy Ash to see menacing looking pointy needles of fibre sticking up but on this one the fibres were indeed shorter and blunter. I certainly wouldn’t want to fell one with a significant lean in the wrong direction.

I don't get this!

I could kind of accept that local to the point of infection there may be some changes in wood characteristics but even with advanced dieback within the crown I can't imagine it would alter the base of the stem.

 

My thoughts are based on how trees react to the DED fungus, compartmentalising infected twigs, tertiary and secondary branches - a progressive compartmentalisation process. I imagine that ash reacts in a similar way.

 

Could it be that as the vascular function diminishes with the loss of foliage/water uptake the lower moisture levels reduce the strength of the wood fibres in tension? I dunno :confused1:

 

The FISA guidance I read this week (IIRC) focused more on not using wedges for felling due to the vibrations causing dead limbs to fracture. Can't remember much about short grain when felling.

 

EDIT. Would/could drought conditions alter 'fibre strength'? Could there be a relationship there? 

Edited by Gary Prentice
Link to comment
Share on other sites

1 hour ago, Gary Prentice said:

I don't get this!

I could kind of accept that local to the point of infection there may be some changes in wood characteristics but even with advanced dieback within the crown I can't imagine it would alter the base of the stem.

 

My thoughts are based on how trees react to the DED fungus, compartmentalising infected twigs, tertiary and secondary branches - a progressive compartmentalisation process. I imagine that ash reacts in a similar way.

 

Could it be that as the vascular function diminishes with the loss of foliage/water uptake the lower moisture levels reduce the strength of the wood fibres in tension? I dunno :confused1:

 

The FISA guidance I read this week (IIRC) focused more on not using wedges for felling due to the vibrations causing dead limbs to fracture. Can't remember much about short grain when felling.

 

EDIT. Would/could drought conditions alter 'fibre strength'? Could there be a relationship there? 

We could do with members posting their pictures of  larger ADB felled trees as Jonny has done, and see if they are similar characteristics.

  • Like 3
  • Thanks 1
Link to comment
Share on other sites

Just now, Paul Cleaver said:

We could do with members posting their pictures of  larger ADB felled trees as Jonny has done, and see if they are similar characteristics.

Seems like there are a lot of unknowns with this disease, so every ones experiences and observations are useful and would go towards a better understanding. Good idea Paul 

  • Thanks 1
Link to comment
Share on other sites

I have spent a couple of days this week felling oversize diseased trees. Tbh any decay at the butt end could have been expected of trees of that size on that particular type of ground. 

I have felled a few parcels now , and certainly from a felling point have seen little difference in how the trees respond to non diseased trees.

I did take photos ,but sadly they are of poor quality and would be of little value to the discussion.

Link to comment
Share on other sites

I have mentioned a few posts back the observations we found when recently felling 550+ Ash with ADB, some with poor crowns, some completely gone.

I would estimate that 50 percent had some basal decay but no external sign/fungus present on the butt, these are plantation trees, not coppice stools and drawn up well in a mixed Beech compartment, no drought issues have been noted in any other tree species in this compartment, so why would drought only effect the Ash?

Link to comment
Share on other sites

  • 3 weeks later...

I manage and work in a woodland in North Devon. We have quite a few ash in certain parts of the site. During the summer I had noticed a few showing signs of dieback, but have now noticed quite a few completely leafless crowns. Would you assume that they are dieback and remove if in a high traffic area and if safe to do so or would you expect some ash to have completely lost their leaves at this time of year?

Thanks for any thoughts

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share


  •  

  • Featured Adverts

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.