I was in Belgium last month where Koen Carolus of Carolus Trees in the St. Truiden region showed us their 'fruiting wall' method of producing apples. (Video.) In a nutshell, all pruning is done with a hedger, and usually just once a year. Huge labor savings. Does it work? Growers claim higher yields of medium-size, above-average quality of fruit are produced on dwarf trees spaced app. 3 ft. apart. Otherwise, the trees would have been managed like a tall-spindle.
Of course I had to try it myself, so I split a row of Silken apple trees on M.9 rootstock going into their 4th (5th?) leaf up into 2 groups -- either fruiting wall or tall spindle. I bought a B&D battery-operated, hand-held hedger at Home Depot and gave the fruiting wall trees their first haircut just after bud-break. They will receive another hedging when about 8-10 bourse shoot leaves develop.
Here you can compare the bloom density of the two systems -- fruiting wall or tall spindle. What do you think?