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Fungi on Apple Trees

Last post 23-02-2010 5:03 PM by dimitri. 13 replies.

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  • 18/01/2010 10:19 AM
    • abbamech
    • Eastbourne
    • 18 Jan 2010
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    Hi Everyone Newby to this forum as I am trying to identify what is killing my apple trees, I have what looks like a very large Bracket Fungi mid way up an old apple tree that weeps a clear syrup like substance in the Summer. Since the Summer the Bark above the Bracket Fungi has died off and come away leaving a dead limb, it also now seems to be spreading to other limbs on the tree. I have looked for Mushroom like speres, Ryzones etc to see if it could be Honey Fungus but it does not seem to be. Would love to post a picture but can't see how to in this forum? any help would be great as it looks like the problem is spreading! :-( Thanks to support here's a link to a picture http://www.flickr.com/photos/46751870@N08/4284807456/

  • 18/01/2010 10:40 AM
    • miranda
    • Oxfordshire
    • 17 Nov 2004
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    Sorry to hear about your apple tree, abbamech. You can find instructions for posting photos here: http://mygarden.rhs.org.uk/forums/t/18506.aspx

  • 30/01/2010 12:37 PM
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    Hi, sorry arto hear about your tree, it would be good to get a pic up, there are various forms of Armilleria ( honey Fungus ) and Bracket fungus. Unfortunatly it sounds like your apple tree is in bad shape, because of this it would be advisable to have the tree removed and stump ground at to prevent further attackes.

  • 30/01/2010 01:38 PM
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    What a whopper!

    Fungi are notoriously hard to identify. Inonotus hispidus is the most common bracket fungi to be seen on Malus (apple) species. Do a google image search for "Inonotus hispidus" and you'll see what I mean - depending on its age, the ambient humidity & temperature and the type of wood its munching on, it can have a dozen different faces.

    This chap is feeding on the heartwood (which is effectively dead) in the core of the larger branches and trunk of your tree. Only an expert could come round and say how far it has spread, but, as far as I know, amputation is the only way to remove it. Since this will expose big patches of heartwood on an already weakened tree, the chances of re-infection are high. The advice above to thoroughly remove this tree, stump and all, sounds like the best plan to me. Again, you would need a pro on the ground there to be sure.

    On the bright side, older apple trees become less productive anyway and young trees tend to be fairly immune to fungal attack.

    Good luck!

    www.ashridgetrees.co.uk
  • 18/02/2010 10:34 PM
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    The colour and upper surface of this fungi, put me in mind of Inonotus hispidus, aka shaggy bracket. Can you recall if the upper surface looked/felt felted/hairy? This species commonly grows on Malus (Apple), amongst others. It is a plant pathogen, although I'm not sure how virulent it is. It is classed as a white-rot fungus that destroys lignin and cellulose. It causes brittle fractures of tree limb/s and is associated with old wounds. It can affect neighbouring trees if they have open fissures/wounds where the fungal spores could access. I don't believe there is any remedy available for the domestic gardener. Usually the best way to irradicate such fungi and attempt to stop it from spreading, is to prune out the affected limb of the tree and burn it, although their is no way of telling if the infection has spread throughout the tree. If it appears elsewhere on the tree at a later date, this is indicative that it is dispersed throughout. In which case you should fell the tree and burn it.  Sorry I can't give you more positive advice.

     

    PS. Just read the Hedge Folks post above mine. They think it's Inonotus hispidus too! - we both seem to have come to the same conclusion - so it's looking likely to be this species. 

    Chris
  • 19/02/2010 10:25 AM
    • dimitri
    • Devon
    • 14 Jan 2010
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    I dont think this is Inonotus hispidus, it looks more like a species of Ganoderma.  The brackets are quite easy to tell apart:

     

    Inonotus hispidus is fleshy, leathery, hairy on top.  It is annual, appearing in summer and gradually rotting to a nasty black mess which persists into the winter.

     

    Ganoderma species are hard and wood-like, not hairy.  They are perennial and every year they add a new layer to the edge which is white at first, becoming brown.  There are several similar species, you cant tell them apart from a photo.

     

    It is relatively immaterial, except to mycologists, which species or even genus is attacking your tree.  Bracket fungi enter the dead heartwood of trees through cracks or pruning cuts and grow there, feeding on the wood and decaying it in the process.  Eventually they grow out to produce the bracket-shaped fruiting bodies which liberate airborne spores.

     

    Bracket fungi do not kill trees because they do not attack living bark or sapwood.  However, the decay weakens the structure so that the branch or the whole tree may fall.  If it doesnt it can become completely hollow which is very good for wildlife.  If your tree poses a potential hazard to people or property you should take steps to make it safe, either by cutting back, or bracing or propping it in some way.  Gardeners are responsible in law for the safety of their trees and you could be in trouble if it falls on the postman or the neighbour's shed.

     

    Because the living parts are unaffected the tree can go on producing apples for many years.  I would therefore assess whether it poses a hazard, brace it if necessary and let it be.  There is no point in removing the bracket, when spores are in season they blow for miles and the air is full of them.

     

    You mentioned honey fungus, which this definitely is not.  Honey fungus almost always produces its clumps of honey coloured toadstools  from the base of the trunk, or from infected roots below ground, for a few weeks in the autumn.  Honey fungus enters the root system below ground and very rarely spreads up the trunk.  Apples are very susceptible, but as with brackets, trees may live for many years with infection in the roots.  Even when the weakened roots fail and the tree  falls, it may live and go on producing apples for many years as long as some roots survive.

     

    The tree could quite possibly have honey fungus infection in the roots as well as the bracket fungus in the trunk, but there is no evidence of it in your photo.

     

     

  • 22/02/2010 02:36 PM
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    I agree with you regarding the definitions of Ganoderma spp. and Inonotus hispidus and I definitely do not think this is Honeyfungus (Amillaria sp.) However, you may not have noticed but this photograph was taken during the growing season (as there are leaves on the tree) - so it could easily be I.hispidus. I agree I.hispidus brackets grow annually then wither, but I see no white growth on the rim to indicate this might be Ganoderma spp. The growth on the upper surface looks hairy, as if it were flocked and has a reddish brown colour. Can you suggest a Ganoderma species which has these characteristics? 

    Chris
  • 22/02/2010 04:04 PM
    • dimitri
    • Devon
    • 14 Jan 2010
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    M7 hydropiper

    I've had another look at the photo and I cant see any hairiness on the upper surface.  There is a rough patch which looks to me like crumbly rotten wood which has fallen down from the rotten bit of the tree just above.

    The white rim on some Ganodermas is relatively transient, the new growth is white when it first appears, for a month or two, but then turns brown as it matures.

     

    The undersurface is just visible in the photo and looks whitish to me:  another Ganoderma feature.  Inonotus hispidus is rusty brown underneath.

     

    The key feature is whether it is hard, wood-like and perennial, or leathery and decaying in the autumn, ie annual.  I'm staying with Ganoderma unless we get fresh information to the contrary from the original poster.

     

    There are four species of Ganoderma in Roger Philips' Mushrooms (the best book I know on the subject of UK fungi) and none have a hairy upper surface.

     

     

  • 22/02/2010 05:56 PM
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    I have the Roger Phillip's book. It is probably the best for photo identification. But it does not include any keys - which are also useful when making identifications. The underside of Inonotus hispidus is not rusty brown, more of a caramel off white colour. It also characteristically holds water droplets on the underside, which you can just see in one of the two photos provided. See also this link:

    http://images.google.co.uk/imgres?imgurl=http://www.naturephoto-cz.eu/pic/ceteri/preview-inonotus-hispidus-15740.jpg&imgrefurl=http://www.naturephoto-cz.eu/inonotus-hispidus-picture-3250.html&usg=__URIxWnXzwusDdfhseekKZvO6Scw=&h=100&w=138&sz=7&hl=en&start=34&um=1&itbs=1&tbnid=WEqjMzeewzQO0M:&tbnh=67&tbnw=93&prev=/images%3Fq%3Dinonotus%2Bhispidus%26start%3D20%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-GB:official%26channel%3Ds%26ndsp%3D20%26tbs%3Disch:1

    I woudn't say the upper suface looks is hairy as such, it has more of a felted matt appearance as in I.hispidus. The "crumbly rotten wood" which you see on the upper surface right hand side, I think is the bracket beginning to breakdown, at the start of Autumn. This photo was taken in mid-September. I'm going to post these two pictures on a natural history website I know, and see what other people think. Unfortunately, I'm not sure that we shall hear back from the person who posted this as he/she only seems to have made one post, and hasn't made any comments about our replies. 

    Chris
  • 23/02/2010 09:41 AM
    • dimitri
    • Devon
    • 14 Jan 2010
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    Not sure we can get much further with this without more information. These fungi are quite variable and also their characteristics change as they grow and mature.  The original poster could confirm things one way or the other immediately by having another look now in February:  if its Ganoderma it will look much the same, if its Inonotus hispidus it will be a black squishy mess and may have fallen off.

     

    The photo of I. hispidus on P.310 of the latest edition of Phillips' book shows the underside as rusty brown and he describes the pores as "pale ochraceous at first, later brown and glancing in the light."  The specimen in the photo you posted is a young one and is indeed "pale ochraceous" on the underside and similar in colour to the original post.  The pores of Ganodermas are pale.  I think exuding water droplets is not diagnostic for I. hispidus, it is something many brackets do when young and actively growing, but dont quote me on that.

     

    However, the original photo was indeed taken in September (well spotted, I hadnt noticed that) and if the bracket is I. hispidus it is unusually late for a fresh one to have just appeared, they are supposed to appear in summer.  And if it is an old one and is beginning to break down as you suggest, it will be mature, brown underneath and starting to blacken.

     

    On the upper surface we'll have to agree to differ, it does not look hairy to me, it looks smooth and brown and very Ganoderma-like.  And I still think the stuff on the right hand side is crumbly rotten wood from the rotten patch immediately above.  It is so decayed that you can see daylight through it.

     

    The lack of keys in Phillips latest edition is  a drawback, the earlier edition had a very useful simple key to genera based on spore print colour.  However, that might not help us much here, since Ganoderma has brown spores and I. hispidus has "rust" ones; whether that was a useful distinction, would depend on whether that was rusty orange or rusty brown.  The spores of Ganoderma are definitely brown, I havent seen those of I. hispidus

     

    Anyway this is all rather academic for the original poster since whichever of us is right, the effect on the apple tree will be much the same.  The good news is that we both agree it definitely isnt honey fungus.

  • 23/02/2010 10:38 AM
    • abbamech
    • Eastbourne
    • 18 Jan 2010
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    Thanks to everyone for your great technical knowledge and insight, having read the post's I shall try to clear up some of the questions raised about the bracket.

    it does apear annualy (and has spread to other limbs/trees) during the summer its a firm mushroom like texture, with a velvety top and through Autumn to winter it turns black, goes mushy and falls off the tree.

    Essensially its pretty much as per the description by Dimitri "Inonotus hispidus is fleshy, leathery, hairy on top.  It is annual, appearing in summer and gradually rotting to a nasty black mess which persists into the winter."

    All that said things have come to a head as one of the trees went over in strong winds and while our 'tree man' was in pollarding the big willow and other trees we had it chopped and stumped (through the core of the trunk there was a black ring around the cambium/hartwood) Considering the poor condition and age of three other trees in close proximity we have had them removed and stumped aswell.

    My only dilema now is  - can we replant trees safely in the same area?

  • 23/02/2010 12:18 PM
    • dimitri
    • Devon
    • 14 Jan 2010
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    Thanks abbamech, that's interesting and I was wrong, Inonotus hispidus it is (or was).

     

    As for replanting, you are not at risk from I. hispidus, that does not contaminate the soil.  However, I dont recommend that you replant with another apple or related tree, because there is a risk of replant disease.  These problems occur when the same species, or relatives, are replanted on a site where the species was previously grown.  The replanted tree does not thrive, it is thought because a build-up of root pathogens in the soil around the roots of the previous tree attacks the roots of the replant and make it unable to establish properly.  Unfortunately, in the case of apple and "relatives", that pretty much rules out all the usual fruit. You could try an unrelated tree:  how about a walnut or a fig?

     

    If you do want another apple in the same place, you could change the soil: it is quite safe for vegetables, so you could swap it with soil from the veg patch.  However, this approach is more practical for smaller plants like  roses, which also suffer replant problems, it would take an awful lot of digging to remove and replace all the soil containing the root system of a mature apple tree.

     

    A compromise would be to dig a hole big enough to accommodate a cardboard box, sink that into the hole, punch a couple of holes in the bottom and fill with fresh soil.  Plant the new tree in the box which will protect the new roots from infection from the old soil.  By the time the box rots away the tree will have (hopefully) established sufficiently to grow away.  No guarantees, but I've seen this suggested for roses.

     

    You should be safe to plant another apple outside the root zone of the old one:  as a very rough guide, the root zone spreads as far out underground as the canopy did above ground, so two or three metres away should be OK.

  • 23/02/2010 12:28 PM
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    Thankyou for clearing this one up abbemech. dimitri and I thought we'd never find out the answer! But as I suspected it was Inonotus hispidus, as it grew annually then decayed come winter. 

    Removing the trees was the safest option to irradicate the problem. Well done for being brave, it's hard to admit defeat sometimes when faced with pests and diseases.  But as you saw the infection may have spread to other trees and had begun to decay the heart wood. I am facinated by fungi, so I find all this pretty interesting even though it led to the demise of your apple trees.

    I would suggest it's definitely not safe to replant with apples or woody plants within the Rosaceae anytime soon. If you do plant more apples they may appear unaffected for the first few years, but it is likely that spores from the fungi will persist in the area, or your neighbours gardens, the infection may take hold unseen and the first you'll know about it is 5/6 years down the line when a bracket appears (the reproductive part of the fungus). But then it is often too late to control.  Elm, walnut, and particularly ash are also favoured hosts of I.hispidus, so I would avoid replanting with those. Depending on how host specific this species is, (not very it seems considering the range of trees it grows on), I would go for trees that aren't considered to be affected by this fungi (you could try researching this on the internet but I don't know whether there are any offhand). Or, of course, you could simply not plant any more trees in the immediate area, and any new plantings keep well away from the area where the infected tree was, but understand that anything you do plant may be affected in subsequent years.      

    Sorry I can't be more positive. Hope some of this helps. 

    Chris
  • 23/02/2010 05:03 PM
    • dimitri
    • Devon
    • 14 Jan 2010
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    Abbemech, I dont agree with hydropiper's comments concerning persistence of Inonotus hispidus and stand by my earlier suggestion that the only thing you do have to be concerned about is replant disease.  There is no significant risk of residual infection from I. hispidus spores claimed to be contaminating the environment.

     

    Hydropiper, the spores of some root-infecting fungi and fungus-like organisms (eg clubroot, Phytophthora, onion white rot) can contaminate the soil for long periods.  However, Inonotus hispidus is a top rot.  The airborne spores are released from the bracket during the summer, land on wounded wood or pruning cuts and grow into the exposed wood to create a pocket of rot in the heatwood of the upper parts of the tree.  The soil plays no part in the life cycle.  The spores (basidiospores) are not persistent and are degraded above ground by ultraviolet light, heat and desiccation.  Any that fall onto the soil will eventually be destroyed by bacteria, protozoa and other microflora.  They do not persist for years, either above ground or below.

     

    So in my opinion your statement "... understand that anything you do plant may be affected in subsequent years."  is true only to the extent that there is always a risk that new spores may blow in every summer from new fruiting bodies in the area.  It is not the case that the now destroyed fruiting body will have led to any significant contamination of the immediate environment.

     

    I sense a risk that we may carry on arguing this one, to the continuing confusion of the original poster.  Abbemech, you dont have to believe either of us.  If you are an RHS member, you can ring their advisory service for advice on the arguments we have presented and also request their advisory leaflets on tree decay fungi and replant disease. 

     

    You can also contact The Tree Advice Trust (www.treehelp.info) who run a Tree Helpline on 09065 161147, calls cost £1.50 per minute, or the Disease Diagnostic Advisory Service of Forest Research (the research agency of the Forestry Commission) www.forestresearch.gov.uk   The latter is strictly speaking only for diagnostic work on tree problems or identification of decay fungi, but I think they would be OK to advise on the spore contamination issue.