Cummins Nursery has list of disease resistant apples. Then you need to match it with rootstock that is resistant to specific issues you might have in your area. I don't have much of an opinion here except that I'm not impressed with the widely used mm106 semi-dwarf rootstock due to its tendency to rot.

Here is a link that might be useful: Disease Resistant Apples

The most disease resistant are:
Early: William's Pride
Midseason: Liberty
Late season: Goldrush

Not only are these the most disease resistant varieties, they are also all varieties with very good reputations, especially Goldrush.
Liberty is triploid and as such will require two pollinators. Good choices for this will be easy to come by as there are many mid-season DR varieties. Good choices for DR would be Redfree and Priscilla. William's Pride (although early) will serve as one of the Liberty pollinators.
ALL the varieties I mentioned are PRI (Purdue, Rutgers, Illinois) introductions. I'm not affiliated with PRI, it's just that they've by far been most active in DR breeding and have also been, the most successful at it.

Thank you i have some studying to do.

Liberty , a diploid, was developed by the the New York Ag station in Geneva , N.Y.

A triploid does not require two pollinators. The reason three species are needed when a triploid is involved is because the other two must pollinate each other since the triploid has sterile pollen. The triploid takes pollen from either or both of the others. I don't think Liberty is a triploid though.

Yeah...I goofed up there. I don't know what made me think it was triploid. I also thought for sure it was a PRI apple, but I checked and you're right malus...diploid.

Thanks guys, not to worried about pollinators have about 10 crabapples planted about 10 years ago. Can I mix pear trees in with the apple trees?

Why not? Kieffer is a common disease resistant and self-fertile pear.

Whatever you do, make sure the pear is not on Provence Quince rootstock. It is not very hardy and has a tendency to iron chlorosis. Some nurseries still use it because is it can get a pear tree down to 10'-12' range. OHFx333 or OHFx87 are better options even though they don't limit the tree height as much.

Disease resistance is highly over rated. For instance Liberty is a sponge for plum curculio, and all apples in the northeast need to be sprayed for this and other insect pests. Not much more work to throw some myclobutanil in the mix and grow some delicious varieties of which only Goldrush fills the bill in terms of "world class" flavor in my book.

Sure, William's Pride is good for a summer apple, but I ate a Zestar yesterday and it is the first apple I've tried so far this summer that I actually ate to the core.

If it is important to grow organic, Goldrush may be difficult because it is highly susceptible to cedar apple rust- it only resists scab. Disease resistant apples are generally only worth growing if you are planning on spraying with Surround only to produce organic fruit.

I'm with harvestman on this - insect damage is always a bigger issue for my home orchard than any disease problem.

I have three Liberty and wish I only had one. It's an okay apple. I bought disease resistant apples when first planning my orchard and Harvestman is right you have to spray for bugs and some disease anyway why not get better apples. Gravenstein is a very good summer apple.

The only issue I've had is rot on a couple trees I bought. It seems Macoun is the highly susceptible to Bot. cankers. However, I don't spray my apple trees at all.

My parents have small orchard of unknown varieties that was on their property when they bought it about 35 years ago. There have been no issues with pests or diseases. The trees have never been sprayed in the 35 years they have been there. The only issue is Sooty Blotch and Fly Speck on the fruit, but that is just cosmetic. The biggest threat to the trees has been the fast growing vegetation that surround the area. Other than clearing the area, the trees take care of themselves. My parents have never really been into maintaining the orchard. My grandfather an I use work at it when we could, but those days are gone. I do what I can when I can. I think the last time they were pruned was about 20 years ago. They still give truck loads of good size apples about ever other year. Apparently, those trees gave me a false impression on how hardy apples are in general. Aside from the threat of late frosts, the area must also be paradise for apples. No Fire Blight and no pest since I can remember. There are some other blights, but they don't seem to affect the apple trees much.

Here is a link that might be useful: Cankers and Macoun

Nyrock, where are you? Every site I manage produces nearly useless apples most years without spray unless you have very low standards and don't intend to store anything. In other words, you can cut away some useful fruit fut there are bumps and tunnels that take away the enjoyment of eating whole apples plus they rot in 2 weeks in storage.

Please show us some pictures of this years harvest if you get the chance.

I have seen old strain yellow delicious and winesap produce decent apples without spray, but not nearly as nice of fruit as with.

I too have never seen what I'd call even remotely decent apples anywhere around here that was uncared for and I'm ALWAYS looking.
I see abandoned orchards and the odd back alley tree all the time and the apples are worth nothing more than deer bait.
rockfarmer...do you know what the variety is? For all we know they could have been propagated from some lost variety that outperformed all others in disease resistance..maybe has some insect resistance too.
Either that or you have as you say a apple paradise there. I wish my yard was one.
Shamefully, my standards are pretty high. If I can't approach near market quality, I'm out. So far, I've succeeded with apples, plums and pears. Peaches...well..that's a different story.

I don't have plum curculio out here but I do get codling moth, and they love Liberty.

Liberty generates a lot of fruit, and in the right conditions it can be really very, very good, but it can also be a mediocre apple and seems to me to be pretty fussy. It also takes a lot of care if you want it to store very long.

I'm gradually working my one tree over to Karmijn d' Sonneville, Rubinette, Prairie Spy, Jonagold, Haralson, plus some early varieties recommended here. Have a few others in the "we'll see" category.

The trees are on hill tops in Southern Tier NY (1700' amsl). Unfortunately there won't be a harvest this year due to the -18F fruit bud damage last winter. As hardy as the trees are, they obviously aren't polar hardy. Only one pear and one apple tree have any significant fruit.

I'm not camera oriented guy so I never think of taking pictures. Last year would have been a good year to do that. All the trees were loaded. I mostly want pictures to see if anyone can identify some of the older varieties on my parents land. They could be unique, but I wouldn't be surprised if they are antique. I think their resilience could be an example of natural selection (aka survival of the fittest). New trees are coming up on their own and reaching maturity. One type in particular is creating carbon copies of itself across the landscape. I like everything about this variety except the fruit lacks tartness to make it more versatile. The fruit is similar to a Fuji apple. The growth habit of the tree couldn't be more perfect. This is one of the two trees I've recently decided to use as rootstock for my projects.

Most of these full size trees are producing 15-30 bushels of fruit per tree on good years. If only half are good quality it will still be more apples than family and neighbors can use. By good quality, I mean no subsurface defects. Most of the apples get processed for baking, canning, and cider. For cider, I dip the apples in Clorox solution remove any Sooty Bloch and sterilize outer surface. During the whole process I set aside the best looking apples for fresh eating and cooking. The Sooty Bloch and Fly Speck varies from apple to apple on the same tree. Some apples are good to eat straight off the tree. Overall, I don't see the need to spend the time and money to spray the trees. If I were taking these to the market it would be a different story.

I think the cooler zone and the hilltop location might be why there isn't much issue with insects. My two biggest issues are cold weather and fungus related... and this applies mostly to the new trees I've bought. It seems like trees they sell these days are more susceptible to the elements. I'm starting to develop an appreciation for the less market-oriented varieties that don't require so much TLC.

Johnthecook, make some of yours over into other varieties. Easy to get scions and easy to learn to graft. right now I am trying to get a bud graft on every little branch of my peach tree because I don't like the original variety. Did some last year and hope this years gets the rest.

Thank you for your replies. It is not important to grow organic, There is a christmas tree farm across the street. Some of my crabapple have cedar apple rust, I thought because of this disease resistant would be a smart choice. This is also a weekend house, so not sure how much spraying I would really be able to do.

Harvestman, I'd agree with you on the DR varieties if fungal control was as simple for me as " throw some myclobutanil in the mix and grow some delicious varieties". I do always mix fungicide in the mix and I spray way more often than you and that does not mean no fungal issues...at least for me it doesn't.
You mention Zestar as opposed to William's Pride and you've mentioned that before. I keep thinking about that, but it's the fact that it's 2-3 weeks later that presents the disadvantage for me. The varieties just keep getting generally better the later you go. Everything I've read (and you seemed to agree) indicates that WP is about as good as it gets for it's harvest period, whether DR or not.
The only hang up for me is the water coring tendency that ScottSmith alerted me to. Even PRI's own literature noted it's tendency towards water coring.
Having said all that I think WP will be one of the additions to my orchard because I want an early apple and 2 weeks is 2 weeks. The other thing is, I've seen so many photos and videos of WP and damned if it isn't a pretty apple...some getting a very deep dark burgundy/purple. I know looks aren't everything, but good looks never hurt.

nyboy: I don't know what kind of crabapple you have but not all are resistant to CAR, in fact some have susceptibility to it. There are a number of DR varieties that are also susceptible to CAR and most have been bred with malus floribunda to get their scab resistance I think. I sometimes wonder if that's where there susceptibility to CAR comes from.

Appleseed, the reason I mentioned Zestar was not as a comparison to WP, and I agree with your choosing it as a fine mid-summer apple- it's pretty tasty to me and some rave about its flavor, calling it great for any season. For me, Zestar earns that description but not WP, but subjectivity reigns here.

It is as beautiful as any apple I know and in the wide open can be that way without any fungicide.

The mere fact that you agree with my choice is reason enough alone to get it...it's settled. It just may be divine sovereignty lol. Scott seems to like it as well apparently
despite the WC issue.
For me the CAR resistance is huge. Purdue, Cummins and Ohio State call it field immune, while others list it as highly resistant. Zestar on the other hand is listed as "some resistance, although I think I'd like it as well. I've ridden entirely my Honeycrisp of CAR, but the Goldrush has the CAR chasing me all the time.

Appleseed, what is your spray schedule for CAR? I cannot reach every orchard I manage at nearly the precise time I'd prefer, but I've not had more than a few blotchy leaves on any of the trees I've managed in the 20 years I've been using myclo. Many of these orchards only receive two sprays of the stuff- the first around petal fall and the second 10-14 days later.

An earlier spray is only required when there is an infected cedar in the immediate vicinity, but even in this case, only the leaves get infected- the fruit hasn't formed yet.

Harvestman, my spray schedule is to be honest that I really don't have one. Well, I do, it's just that there has always been something that kept me from spraying early. This has not been by choice. This is why I see the great value in DR varieties for the backyard orchard whereas you do not. I'd bet anything my trees receive far, far greater care than the typical backyard tree and my fruit is proof of that.
You might recall I never before sprayed myclo before probably mid July of this year. I also never sprayed dormant oil, but I bought some and will this year.
I sprayed only sulfur and this is the first year ever for CAR and I'm certain the Goldrush introduction served as the petri-dish in my yard. This year:

Chlorothalonil and triazicide before bud break.

Triazicide and sulfur at petal fall (with some scattered petals remaining...bees no longer really active)

triazicide/sulfur about every 10 days, sometimes less depending on rain and insect activity

around late July I began Triazicide/ Carbaryl / myclobutanil about every 6 days (carbaryl introduced for JB control)

beginning early August Triazicide/myclo/ sulfur about every 6 days depending on rain (most effective spray combo to date)

Most recent spray Imidan (1 1/4 tbsp. per gallon) / myclo mixed heavy / sulfur (hasn't rained since)
I did a one time spray to the Damson only of Bifenthrin/ Zeta - Cypermethrin for BMSB. This was the most effective one time spray I've ever did in my life. Tree was covered with them including babies. The spray totally destroyed them and they have never returned nor did they move to any other fruit. Gone like the wind. A single 24oz. spray.

This is certainly an overly excessive spray regimen, but I have absolutely perfect apples, other than a very small touch of what I think is bitter pit on Honeycrisp (only on a few select apples), and the CAR on the Goldrush...no fruit damage whatsoever and only small foliar lesions, never with the horns on the leaf underside.

I spray very thoroughly...leaves top and bottom, trunk branches...everything.
I finish out the tank on the Goldrush with a light mist after the initial spray has dried to get more product on the foliage.
I might introduce calcium sulfate next year, both foliar and ground applications to the apples.