About 30 years ago I planted a variety of apple trees and a few pear trees in our yard, the root stock came from Stark Brothers. I was very consistent on how I cared from the trees over that time period- I did nothing.
I did however branch cut and prune to preferred shapes to let sunlight in, so structurally they look decent and the upside is they serve pollinators and produce nice deer apples every year. Now my grandkids love to pick them and we find a few that are good enough to gnaw on, I tried to tell my Wife, the apples are organic, I was informed – I could do better. What’s my next steps on improving apple quality for next season- start with dormant oil spray early winter? and then??

I spray twice a year, post blossom, and a few weeks later. I prune hard, center out, centers are real open. Cut every straight up or crossing branch I can. I use a hand pruner, lopper, and now own an extendable two cycle husqvarna pole pruner. I have around 24 apple, 3 pear, 5 plum. Apples this year each one pretty much fills my hand, very nice sized, but it is a good apple year.

My wolf river tree was loaded this year still getting apples.

Best apple year I can remember.

I've left ours go feral too

X2 prune and spray pick small apples in areas on tree with bigger apples I try to prune every thing that points toward trunk

In the mid 60's I worked for an apple orchard in Michigan .
I saw a branch that went from one main shoot to another.
These were older trees. not dwarf trees.
He explained to me that it was to help keep the trees from spliting as the trees got bigger.
He said they would take suckers that were growing toward the center , one each from two different main branches.
Wrap them together , and in time they grew into a solid branch between the to large branches.
Never saw a sucker grow from one of them , but he told me if I did to not prune it.
They were strange looking just a 2-3 inch branch the went from trunk to trunk .
Older trees back then, some had short trunks , and two or more branches that were the main trunk for the trees.
I've never seen them since.

Seems he sprayed quite a few times durning the summer also.
I know very little about spraying , but a pre bloom and an after bloom was done .
Then a spray for black spots caused by fungus on apples or other fruit .

I wonder how you'd spray an apple tree without getting the chemical on you. I'll stick w/ free organic apples. If my trees get fireblight, I'd have to look into spraying though. On the apples that have a bad spot, we cut around it & use it for baking.

Most of the sprays are going to be some form of fungicide, usually copper based. Pesticides are not usually sprayed prophylactically but only as indicated by pest presence. Or at least that's the modern IPM approach.

If you turn the pressure up on the pressure tank connected to your well, you can keep most of the fungicide off of you.

Afterwards, just remember to turn the pressure back down. Speaking from experience, short hoses off of the well head will whip around and nail you under high pressure. You get badly soaked too.

Keith

Pressure up and wind/breeze at your back.

I am caretaker of 100 trees of three age groups. One group is OLD 2 foot dia, dont know what to do to these that wont hurt them. The next group is 15 to 20 inch dia. And the last group is 20 years old and8 - 12 inch dia, with cages around these from their beginning. Nothing has been done to them in 30 years or more, except to brush hog around them maybe twice or three times a year. I pullled vines rocks and boulders out and made a lawn around the youngest group and sort of self taught tried to trim them for three years. Last year we had APPLES on every tree and did break branches off because of too many apples on several branches. And I now finally have learned how to properly trim, sort of afraid to take to much of at one time. I have recently been taking off about one half of the branchs to get a decent open air look. I am leaving a lot of big vertical center stuff up (for next year) because I have taken so many lateral branchs of this year. But basically we have NO apples this year due to a rain storm when the buds started to open. This is at 2000 feet elevation Down at town level 750 feet or so there is not the numbers of apples that we had last year. So I am saying no apples here.....jk

I spray on a day with a light breeze from the Southwest, why? Cause any draft blow to my orchard and not on me. I wear jeans, long sleeve shirt, bandana, and sunglasses.

It's tough to tell from the photos provided what's doing the most damage to the apples. As others have said, pruning is probably the easiest first step to increasing quality. Doing a bit of hand thinning would also help.

I don't know much about disease pressure in Wisconsin, but my guess is that you're seeing a lot of black rot. As warrior said, fungicide is the main control. If you want to spray, a cheap Tyvek suit is good protection (just make sure you're well hydrated before putting one of those on in the summer).

If you want to stay organic while reducing disease pressure you can rake out all the rotten fruit and "mummies" from around the tree and toss em in the burn pile. Keeps down the number of spores that will overwinter in the soil/leaf litter.

Your county extension agent is likely a good resource.

^^ This,,and Fertilizer helps too.

I trim trees in March, aiming to trim back by a third. Vertical and crossers get trimmed for sure. Early May I fertilize each tree with a general granule fertilizer. When blossoms appear, I start with fungicide spraying, every 10-14 days. When the fruits appear, I will add an insecticide spray, same schedule. Near mid to end of June, after the natural drop, I will thin the apples to no more than one apple every 12 inches of branch. Spraying continues all summer, every 10-14 days, depending on weather. Definitely spray the day before a hot, humid spell. Around mid September I stop spraying.

I wear long pants, long sleeve shirt, hat, rubber gloves, safety glasses and a respirator when I spray. I typically spray near dusk, when the wind/breeze has died down and I make sure to stay upwind of the spray.