My trees are too tall

[brian]

I have a small 1/4 acre orchard of supposedly dwarf & semi-dwarf trees in my side yard.  Some are now 15ft tall and producing more fruit than I can ever eat.  Because of this I don't even attempt to pick anything above my reach as there is plenty of low hanging fruit.  I am thinking of topping everything above ~10ft so I have less to spray.  Is this a bad idea?  I'm familiar with pruning recommendations and I have me trees pruned to their recommended shape (central leader for apples, open for peaches, etc.) and this would be cutting off all the leaders.  Given that the trees are old enough to have a proper support structure... any reason not to do this? 

[Solko]

I am not an expert on this, so please do what you think will work. But my understanding is that there is indeed a reason not to do this, and that is that the trees will come back with renewed vigor after you top their central leader. New vigor for vegetative growth that is.
Most commercial pruning systems nowadays try to keep the central leader intact, but channel as much as possible the energy of the tree into fruit production, and not vegetative growth. This limits both pruning and the tree's response to pruning heavily.
The way this is usually achieved is by keeping the natural habit of the tree, in most cases a central leader, pruning the tree to have a limited number of sidebranches, and then bending these down until below the horizontal. These branches will develop fruit spurs and 'drain' the vigor of the tree into fruit production. As a result the trees do not develop lots of unwanted watersprouts everywhere, and also will not take off in hight. Also, you can bend higher branches back to achievable hights.
Yearly maintenance consists of pruning offshoots of your chosen sidebranches and spurs that have developed on the underside of branches.
You might want to look up the 'solaxe' system, if you find this approach interesting.
Good luck!