Dwarf apple/pear trees

April 2015 i became the proud owner of 4 twigs. I potted these twigs - 3 apple and 1 pear. Later that year they produced a couple of branches and a few leaves. The following year (last year) i got a bit of fruit off two apple. The other apple did produce a few very small bits of fruit, but tiny and not really edible.

My question though is about the pear. I got nothing at all. Lots of leaves. Do pears take longer to mature? Do i need a second pear tree?

Any tips on when and how to prune my trees? They are currently about 4ft including the pot. Would they benefit from a mulch of well rotted horse manure?

Thanks