Ash Chalara Fungus spreads

[Rich]

Yes worrying, Just posted the latest from the FC on the front page

http://www.swog.org.uk/news/efforts-ste ... ash-trees/

[Alex]

This is very worrying indeed.

Ash tree's are my favourite.

Fingers crossed.

[Andy M]

Elm, oak, ash - what next?

I for one like to buy locally raised stock if doing any planting. I know it may be cheaper to buy on the internet but to me it is not worth the risk.

Perhaps as a group we should all resolve not to buy imports, although I do realise in a minority of cases that may be the only source of a plant. At least we should be very alert to the risk of disease.

[Alex]

Anyone able to explain why people imported in the first place?

Same happens with livestock too, it's beyond me why people take such risks.

Here's an article from the Farmer's Weekly.

http://www.fwi.co.uk/Articles/30/10/201 ... isease.htm

Doubt it will be until Spring next year until the picture of the spread is clearer.

[Andy M]

Disease reporting can be done via a website http://www.ashtag.org/ There is also a smartphone app that can be downloaded which helps give the location - the Android one has been out a short while and the iPhone one came out yesterday.

[Terry]

yup, bit of a recurring disaster with elm, now ash.
Larch also being clear felled around us due to p. ramorum.
How many more will be found over the next few years following our way of life and trading over the last few decades especially.
Similar issues in the marine world due to ballasting operations as well as hitch hikers on the ships hulls, not to mention in the cargoes.

[docsquid]

I've written a summary of the latest news for the newsletter that will be out in the next 24 hours or so...

In the meantime, the FC have written to all grant holders asking them to check their ash trees, particularly if they were included in planting projects such as ours. We inspected our ash trees at the weekend (planted in 2010, 11 and 12) and found no sign of the disease, which is good. The nursery from which we got them only uses UK seed and the trees were UK grown, however they did (reluctantly) import one batch at the request of a purchaser in 2007 that was affected. That was dealt with, and they have had no other problems since. We are very relieved so far, but still concerned that we could lose over 300 saplings plus potentially a number of mature ash trees to this disease. As well as ash, we have oak and larch, both prone to ramorum infection. We are felling our six larch trees this winter as part of thinning operations, to reduce vulnerability to ramorum infection, but there is a real worry that we could lose both ash and oak, and have our woodland reduced to shrubs (mainly holly, hawthorn and elder) until more diverse species grow up to fill the space.

At the moment we don't know what the containment/control measures will be for Chalara, and that depends on how widespread it is. So the advice being given to everybody is check your ash trees as soon as possible and report anything suspicious. The latest estimate is that the disease has been in the wild in the UK for at least 2 years (by the extent of epicormic growth on affected mature trees in East Anglia). It is quite possibly very much more widespread than initially thought.

[Alex]

Is there any risk of mistaking the chalara for something else?

The sign of dieback of the upper canopy leaves is going to be difficult to impossible due to the season, but are the other tell tale signs of the disease, just as good as a sympton?

I'll be checking around our brook, which has a lot of ash growing and holding the banks up. I hope to God this is dealth with effectively, and also wish everyone the best in the East.

[docsquid]

It is difficult at this time of year. Many of our ash trees have already lost their leaf. However the Forestry Commission pictorial guide and the AshTag app have good pictures. The key things I looked out for were stem lesions around or below a side shoot, evidence that the midrib was dying off before the leaf (in autumn dieback the leaf goes brown but the stem and midrib stay green) and cankers anywhere on the stem. So far, none of these. Thankfully. Harder for mature trees, ours are mainly saplings so easier to inspect.

[Stephen1]

It's actually pretty difficult to spot symptoms on ash at this time of year i.e. late autumn. Ash loses its leaves earlier than most other trees and once the autumn colours start to 'appear' you see many previously masked lesions on the leaves resulting from a multitude of different causes- many of which may look superficially like chalara f. infection. If you haven't had any hard frosts yet then another thing to look for is small fruiting bodies (like mini toadstools) on the mid-ribs (technically known as a rachis) of the fallen ash leaves. These can be found from about early July until mid November (or until the first Hard Frost- whichever is the earlier). As Docsquid says it's hard to look for the signs of recent infection on mature ash trees, so keep your eyes on the ground as well and look for tiny mushrooms on the leaf mid-ribs.

These mushrooms are the most dangerous stage. These produce millions of spores that are carried in the air capable of infecting trees within a 12mile radius. Once these start getting produced it's going to be very difficult to contain the problem - and very expensive to try.