It could be that they aren't being pollinated. Apples and pears need to be cross pollinated. So, you need to have two different varieties to produce fruit

Another reason could be that the blossoms have been damaged by freezing temperatures. The blossoms will still appear normal, but it won't form fruit because the cold weather has damaged the parts of the blossom that the fruit comes off.

Welcome to Goy Wilmax.
I agree with Myron, in so far as the temperatures causing problems.
As for the different varieties..I'm not so sure as Orchards of all the same apples produce fruit. Do you know what variety you have?

I was under the same impression as you Waddy; That it needed a male flower to pollinate the female flower like for example a fig tree. A friend told me some years ago that this isn't the case with apple and pear trees. I suspect that an orchard could have a couple of trees of different variety to solve this, but I'm only guessing. Out of curiosity I Googled it and downloaded the following information...

Successful Pollination

"In order to have successful pollination, it is necessary to have two different varieties of apple trees. Most apple varieties are self-unfruitful, which means their blossoms must be fertilized with the pollen of a separate variety in order to achieve good fruit set."

I would assume from this that some apple trees are self-pollinating, but not all. Maybe some orchards are the self-pollinating variety, but I don't know.

Ah, that answeres the question. I always thought it meant you just needed two trees in order to get fruit, thanks for putting me right.

Thanks for your thoughts. I wondered if there was some sort of disease as the leaves do go brown. But the pollination issue could be the reason for it. I had such a lot of blossom, it looked lovely. Shame about the apples though.

If you want apples, then I suppose the answer would be to buy another type of apple tree to pollinate it or try and convince one of your neighbours to get one ;o)