In uk.rec.gardening Martin Brown wrote:
: On Jul 10, 10:18 am, (Nick Maclaren) wrote:
: In article ,UHAP...@alpha1. rhbnc.ac.uk writes:
:
: | Dear All,
: | I have a sick apple tree which is *covered* in mistletoe. The
: | variety is Howgate Wonder. It is about 30 years old and it had more
: | mistletoe than apple leaves and stems and the apple leaves are scruffy and
: | yellowed. The really strange thing is mistletoe shoots are emerging all
: | over its branches. As I understood it, mistletoe propagation requires
: | seeds to be inserted into the bark (eg. by birds) -- I'm sure this cannot
: | be the case here. It is as though the mistletoe has 'invaded' the apple
: | tree's tissues and taken over. Does this make an botanical sense and has
: | anyone seen anything like this before?
:
: No, and no, but it sounds very odd.

: I think it can throw out new shoots from the internal parasitic
: structures - particularly if you crop off the existing exterior

Interesting. How would one determine if the mistletoe had made these
'internal parasitic structures' ?

: growth. In the UK mistletoe has never been aggressive enough to see
: off a tree - although on the continent either a more aggressive form
: or the warmer summers seem to make it more of a problem. I suspect
: global warming may tip things over the edge for some of the weaker UK
: trees with a large parasitic load.

: The other possibility is that the bark on old branches is full of
: cracks and there really are that huge number of mistletoe seedlings

That is the odd thing -- the branches have smooth clean bark -- no
canker etc. The mistletoe erupts from these. Also I should have
mentioned that early this year I fed the tree with N+P+K as directed
by a decent fruit tree book -- to no avail. All of this tree's
contemporaries (different varieties, all cookers) have small amounts
of mistletoe on them but no sign of sickness.

: growing on the tree. Worth looking to see that there isn't some other
: sap sucking parasite like woolly aphid making matters worse for the
: tree. Most trees I have seen in the UK co-exist happily with their
: mistletoe.

I'm pretty sure there is no serious woolly aphid infestation.
Ornamentals seem to be plagued by them this year, but I digress...

:
: | A few months ago I cut off most of the mistletoe but the tree still looks
: | pretty sick. Is there any hope for it?
:
: Unlikely. And the cause won't have been the mistletoe. 30 years is
: about the life of many apple trees.

: Could be old age, but I'd look for some other cause first. And maybe
: try an anti-fungal spray too.

Sure.

: Regards,
: Martin Brown

Thanks to all who followed up.

--
Tom Crane, Dept. Physics, Royal Holloway, University of London, Egham Hill,
Egham, Surrey, TW20 0EX, England.
Email: T.Crane at rhul dot ac dot uk
Fax: +44 (0) 1784 472794