I spray them if either my sprayers are not broken down or I'm not broken down.
Lately all they get is spot spraying from my two gallon sprayer, when I can.
The three I mentioned give us more apples then we can handle, even when I can't spray.
This summer we only spot sprayed Caville Blanc. The other 12 or so got no spray, since it was dry here all spring and summer.
Caville Blanc gets attacked by brown rot. Keep Sake tends to lose it's taste in storage. Cox Orange Pippin is outstanding in being pest resistant with great flavor. Early McIntosh scabs badly. Ribston Pippin great flavor, but have not been able to stop the rots. Sweet sixteen has great flavor, and gets by most years without needing to be sprayed. Hudson's Golden Gem would be good for organic growers. Ashmead's Kernel is another one that should be good for organic growers, Freyburg out standing flavor, but needs mulch and a lot of organic fertilizer to get tender fruit, and a spray program to get good fruit. Pittmaston Pineapple fruits rot badly. Espous Spitsenburg is hard to grow because of rots. But, I keep it anyways because of its outstanding flavor from the few good ones I get.
A lot of progress has been in the last 50 years in growing apples organically. If one selects varieties that have proven to grow a reasonable amount of good fruit, in their area, they should be able to succeed. But, I don't think it can be done with apples grafted onto dwarf root stock. The deer will never allow them to grow. Plus, I'm not certain the root system on the dwarfs can spread out enough to reach all the nutrients, the tree will need to fight off pest.
Bob Harper @ T. Pine