Are you saying the fruitlets fall off (tiny baby pears)? And is it all of them, or just some of them?

When you say patio pear is it planted in a pot or is it a minarette tree? If it pot-grown then think that part of your problem is that the pear tree needs to be planted out in the garden. Container fruit trees react quickly to any major changes in conditions such as lack of water and the first thing they will do is to drop any potential fruit although lack of polination could also be a problem.

Thank you both for your replies.
All the pear buds left after the blossom falls have all fallen off i purchased the pear tree as a patio orchard tree with also an apple and plum. Having checked the others i think they are going the same way although last year i had a good crop of apples and a few plums could it be the continuous weather changes. My husband said they have turned black as he cleared all the debris which had fallen up

I hope you've access to one or two of the fruitlets which fell off and turned black - I'd like you to cut one open to see if its full of whitish orange maggots. Pear Midge infestation causes fruitlets to turn black at the 'eye' end of the fruit, and it falls from the tree, turning completely black eventually - cutting open fruits to see what's inside is definitive. If it is pear midge, you will need to spray your tree just before bud break next year, just as the buds are starting to show white, but before they actually open.

Thank you very much found you were correct there is maggots inside so we will take your advice and spray next year. Your help in solving my query is much appreciated and i hope next year is more successful thank you very much.

The only effective pesticide sprays left for this are Bayer Sprayday Greenfly Killer or Westland Plant Rescue Fruit and Vegetable Bug Killer, both sprayed at the time mentioned in my previous answer.

It is difficult to time spraying right. If it didn't work, pick off every fruitlet when it has formed and before it drops and burn them all. This breaks the cycle.

Pear midge often affects only one tree out of many and this is wholly effective in my experience.