On 29/04/20 23:44, alan_m wrote:

I have an (eating) cherry tree that 10+ years old. This year the tree
has what appears to have two dead branches of around 3cm diameter where
the branch meets the main trunk. Early in the season the branch ends
produced the start of leaf buds but since any activity on the two
branches ceased. The ends of the branches can be easily snapped with no
hit of living wood in the centre.

There never is on any tree. The centres of a tree's branches and trunk
are fully lignified for strength. If you want to see if a branch is
alive make a small scrape on the bark to remove the outer layer. If it's
green underneath it's alive. If not, it's dead (this still holds true in
winter when deciduous trees are dormant). There is a small minority of
plants (eg clematis) which do not follow this rule, but in general it's
a useful test - make several scrapes, starting furthest away from the
trunk until you find green underneath. Then cut the branch off close to,
or even through, the green bit. If the tree is healthy, the cut will
callus over. It's a good way of dealing with dieback.

Any ideas why two fairly large branches, with many sub branches, have
completely died off. There is no sign of physical damage.

So no leakage of sticky sap which might be a symptom of bacterial
canker. It looks as though the channels through which the plant moves
food and water have become blocked, and so the distal ends of those
branches have died. Whether this is as a result of an infection causing
the block, or the tree itself protecting itself from the infection
spreading is difficult to say.

The rest of the tree appears very healthy with leaf production, masses
of flowers and many fruit set.

That's a good sign.

Last year the tree produced a bumper crop of cherries but unfortunately
the weather didn't help with a long dry spell while the fruit should
have been swelling and then a wet spell which caused most of the fruit
to have split skins where rot set quickly in.

We are still very early in the growing season...

--

Jeff