Apple tree rescue

An acquaintance has several apple trees in his yard. I'm trying to find out what varieties he planted, but the questions i have are probably general apple tree stuff.
My sister reports the apples get about 1/2 grown and start rotting on the limb. The deer get the rest so she's not tasted a single apple off 5 trees in several years.
The trees appear healthy with numerous blooms.
I have no idea about fruit trees yet. I have some pear and plum cuttings rooting in a windowsill. I have several plum and peach pits stratifying in the fridge. We have just about reached the extent of my current knowledge of fruit trees 🙂 I am reading and learning...
Any help would be appreciated!

Oh, there's a peach tree with the apple trees and the fruit from it is doing the same thing. Thought that might have been a clue, as well.
I'd bet taking cuttings from these trees would be a bad idea, huh? At least until they could bear fruit, anyway...

Michael,
I'm no expert either, but It sounded like a fungal infection to me.  Not scab, that tends to blemish the leaves as well and the fruit carry on to ripen rather than rot completely.  Wikipedia has a page with a List_of_apple_diseases.  It looks like Monilinia_fructicola may be a possibility, that affects mainly stone fruit (like plums) as well as apples, so the peach being affected the same way would be likely.

(apart from fungicidal sprays) Control is by removing and disposing off all diseased fruit and twig tips in the vicinity.  Pruning to improve airflow in the canopy may help as well.  Hope this helps.

I just noticed Michael said

  I'd bet taking cuttings from these trees would be a bad idea, huh?

If you're just wanting to get some different varieties I would steer clear of these trees.  Firstly, yes they seem to be infected, but secondly they seem to be susceptable to the disease.  I personally would steer clear of importing anything from this orchard to your fruit growing area, it may carry this disease with it.  It may be that other apple varieties have better resistance to whatever the disease is, so if your environment is similar, you're better off propagating from healthy trees that are doing well in your area.
I am very borderline for orchard fruit here.  That hasn't stopped me trying, but I have started with varieties that are known to be more resistant to scab and canker, which will be a problem in my wet, windy location.

Thank you, Nancy! I didn't intend for you to do my research for me. I just hoped one of these experts would be able to say, "Oh yea, that's this problem and it's an easy fix." I do appreciate your reply, nonetheless!
I was on Skye once. I remember it well. It was snowing sideways. Some would think raining and snowing sideways in opposite directions on the same day would be kinda weird. Those folks have never been to Skye.
We were on the ferry, my brand new father and mother in law, and my blushing bride from Glasgow.
On the way over on the ferry the national song about bringing the Bonnie Prince to Skye was playing. Romantic and poetic.
I'm planning a trip to Scotland next spring, but it won't include Skye, more's the pity. I found y'all very nice.

Have the trees been pruned appropriately? Fruit that doesn't size up can be related to a lack of pruning and thinning, as apple trees will tend naturally toward bearing much more fruit than they can actually carry to what we humans consider a proper size, taste, and ripeness. An overgrown, unpruned tree will also tend to be more susceptible to fungal diseases because a lack of air movement lets the disease fester, as Nancy alluded to in her comment about pruning.

Thanks, Matt, yea the trees were expected to thrive on neglect. Never pruned, never tended. I figured a good pruning should be step one.
I would think cutting the limbs this time of year might not be the best for them, but I will have her pinch of 2/3's of the buds and research fungicides. At this point she has little to lose and everything to gain.
When they're dormant we'll go in and prune them back. Maybe in a few years time she'll get a decent harvest. I'll use this as practice for my own orchard and what not to do!🙂

I think you're thinking about it just right.

I just noticed you're in NW Arkansas, so we're in very much the same region. We had a couple sad little apple trees on our property when we moved in, and they very quickly succumbed to disease in our warm, humid climate. Now we have planted disease-free cultivars (from Ames Orchard in Fayetteville, which is a great nursery for those of us in the Ozarks) and we're optimistic that we'll see our first apples this year, in year three!

Hey, Matt
I'm just east of Fort Smith so yea, we're breathing the same air!
Thanks for the tip about Ames Nursery. I hadn't heard of them so will check them out. I had contacted another orchard in Poteau, OK but they acted cagey and didn't wanna give out information.