Nothing now-it is/was just a bad year-here is a recent discussion on the same topic
well to be honest not a lot is going to happen .if your lucky and the bees and warm sunshine come before the wrath of winter you might see an apple,but I think next year is more likely.
Late frosts kill the blossom and lots of rain stops the pollinating insects from doing their work. This year is a very bad year, even though there was blossom to start with it never got a chance to turn into fruit. Give the trees their winter prune and wait for next year.