"Spider" wrote in message
...
On 01/02/2015 15:47, FrankB wrote:
Yesterday I realised I'd made a serious error in sawing off a major
branch )about 5" thick) of a mature plum tree which had been giving the
tree
a lopsided look. I only found out today that you should never prune a
plum
tree in winter due to susceptibility to silver leaf disease. If I treat
the
cut tomorrow by painting with Bayer 'seal and heal' fungicide will that
prevent the problem arising or will 48 hours exposure to the elements of
the
wound already be too late?


It's already potentially too late. Anything nasty will have already
entered the wound. Using a wound treatment now will only seal disease
in. I suggest you wait until the summer and see how the tree reacts.
You may be lucky.

This stuff is a fungicide so by painting it on the wound any spores that
have already alighted there I would have hoped woud be wiped out or at least
rendered inactive. I mean it's possible that silver leaf spores could have
alighted on the wound seconds after cutting. So are you suggesting that the
fungicide sealant has little purpose anyway?