Pear rust, see your other question

Thank you Bamboo.

This is indeed a pear tree, so you are probably spot on with your indication of pear rust.

I looked at the rhs link and apparently there is nothing one can do about it, as fungicides for the amateur gardeners are not available.

I'm afraid that's true - but if you have a Juniper in the garden anywhere, removing it altogether, or pruning out the orange growths/pustules that appear on it, will reduce the problem.