Yes indeed, I'm sure that it must be the 2 gallons of apples put out a few times of week that are making those deer nocturnal. I am guessing that the area that you are talking about is the Romeo-Armada area. Tons and tons of food available....food plots, alfalfa fields, picked corn fields, rye & winter wheat fields, but it must be the apples.
BTW did you store these apples somewhere to keep them cool and yet not freeze ? I assume that you are not buying apples since that would get to be rather expensive quickly.
It sounds like you could make changes and improve your odds of seeing more critters.
Any chance that the woodlot is ready for some logging ? You didn't mention if you have water on your setup. If not, are there a couple of seasonal potholes that you could work on next July with a dozer or backhoe and make them into year round water sources ? How about putting in an acre of food plots in that 7 acre area? Pheasants Forever is a great group for ideas & help. Putting in the right combination of items will draw the pheasants, turkeys, & deer to your dad's acreage.
L & O