Apple Tree Help

Any photos of the leaves, bark, tree.......?

A super-heavy crop (which you say you have in recent years) can be a symbol of a dying tree. Many trees will flower and fruit profusely if they are terminally ill. The idea is to reproduce before they die. The best fruit comes from mature trees which are just slightly stressed (slightly hungry and slightly short of water - but only slightly!).

Maybe the cold wet weather meant that the bees didn't visit the flowers.

Maybe your tree is a variety known for erratic cropping.

Maybe - like some of mine - it has decided to dump all its fruit. Just a week or two before they should be ready, my Beauty of Bath and Discovery have dumped their whole crop of golf-ball-sized fruit on the ground in recent days (the June drop is usually the shedding of cherry-sized fruit; not the premature drop of fruit only a few weeks from harvest!).

Maybe you tree cropped so heavily in previous years that it - or the soil - is exhausted and needs a year off. Most varieties will become irregular bearers if not properly pruned, fed or thinned. Note that "feeding" doesn't mean just dump some fertiliser: it means applying particular nutrients after observing the tree, its fruit and its growth to determine how well-balanced the soil.
Shortage of potassium is a major cause of lack of blossom or fruit. Similarly: too much nitrogen will cause growth and not fruit.

Who said it has canker? Do you have some pictures?
Which variety?
Which rootstock?
How old is the tree?
What growth form is it? - tree, bush, espalier, cordon, container?

I have no idea what apple tree it is. It produced blossom this year but nothing else. It has white fluffy sap coming out of some branches. Does this help?.

Pictures would help more Simon

Crap spring, (too hot, too quick, too wet) has messed up fruit trees all over the place. Apples, pears, plums and apricot are all non existent in my garden and the plums at the allotment are no better.

Canker is very obvious, Google for pictures, and if in early stages it can be cured. Copper sulphate helps.

If the tree is healthy and just has no fruit leave alone and wait for next year, you won't be the only one.

Having trouble getting pics. Leaves are crispy and curled with black spots. So sorry I could have saved time and mentioned all this. Its been a long day.

You still don't mention how old is the "tree", nor anything about its size and age.

White fluffy stuff will be woolly aphids.
Blast them off with a hosepipe, or scrub off with a brush and a bucket of soapy water.

In some instances woolly aphids and canker do assist each others life cycle; woolly aphids create splits in the bark where canker can enter, while canker can create splis in the bark where woolly aphids can hide from predators.

The worst thing about woolly aphids is that on young trees they tend to make the branches brittle, which results in an unsound tree structure which may need substantial winter pruning for a few years to bring back a sturdy branch structure.

Black spots will be scab. Scab thrives where there is plentiful rainfall. Some varieties (the common ones) are very prone to scab. Some varieties (especially old rare ones) are resistant.

Severe scab damage to the leaves will prevent photosynthesis, so the tree is unable to manufacture sugar to feed itself or its fruits - the fruits may drop as the tree tries to conserve energy. This would be double-compounded by lack of sunlight in a wet season.

The size and age of the tree (and the variety), along with asking how much scab it has had in previous year, would determine what you should do.

we have no fruit on our russet this year,but this was because of the prolonged cold spell that saw off any chance of the insects being able to pollinate the blossoms,the bramley flowered a lot later and we have a good crop growing on that.my braeburn,which had been dogged by blackspot/scab,was chopped down to 12ins and is now being retrained as a double U shape,we have new branches now 12/14ins long,so we will start to shape them soon into their required form,it may end up as a double W shape,but we do need more sun,we have had 5 days sun over the weekend,but we desperately need more...

Yes, the situation here is getting desperate. We normally expect to be hot, dry and sunny; the plants aren't well-adapted to cold, wet and dark days. I'm actually thinking of adding a couple of ancient Scottish apple varieties on MM111 in order to be prepared if we should see such cold, dark and wet conditions here in the future (although for us it's smashed all records for cold, wet and sunless).
My solar array records show that we haven't had a day of dawn-to-dusk sunshine since late March; our warmest and sunniest day this year was late March to early April.