While looking into antonovka, I noticed a number of other antique apples that had similar characteristics. I was oblivious to all these other varieties that are no longer popular. It seems like it would have been considered a pearmain or russet. Pearmain is a group of apples that have pear like characteristics, which describes this perfectly. From what I can gather, most of these outdated antique apples are extremely hardy when compared to modern varieties. It makes sense. They didn't have the technology and resources to baby the visually appealing, yet fragile, engineered varieties we covet today. Hardiness would have been critical in a low tech world. Now I'm thinking I should try to propagate this tree for rootstock. It's hardier than all the other apple trees I'm familiar with and I like the size (16' x 16').

There are several that have fruit golf-ball sized or a bit larger. Whitney, Chestnut are two good ones that I've grown. And, while TECHNICALLY not a crabapple (I guess, I don't really know what the technical definition is, other than a small apple, somewhat bitterish/astringent and sour) which I think is great for things like jelly and pickled apples is Pink Pearl. Check out Raintree Nursery for the Pink Pearl as well as their selection of crabapples. Here is a link that might be useful: Raintree Nursery

Technically the label is "the law". The active ingredient of Immunox (myclobutanil) is also available as Eagle (liquid form) and Rally (WP) in large quantities for commercial use. Myclobutanil is used on apples and cleared for it for scab and rust issues. Not sure why Spectracide brand Immunox does not list this product for edible crabapples. I have had similar issues with Malathion for apples. One brand at the store listed their Malathion for using on apples for insect control and the other 2 brands that had Malathion did not list it for use on apples on the label. I no longer use Malathion on apples but I got calls at the nursery I work at about this issue so I went to the local chain store and saw the problem for myself. I can't tell you to break the law and apply the product on a crop that it is not labeled for. If your Immunox label says it is cleared for use on apples, then it would be Safe to use on crabapples as well ( that you are going to eat). Perhaps not legal but safe. Since most serviceberries in the U.S. are grown for ornamental purposes only, perhaps Spectracide did not bother to register their product for use on edible serviceberries. Actually all of them are edible but Smoky and many others are grown primarily for the fruit (I am partial to running serviceberry for its excellent tasty fruit.)

It does look like scab. But I would not necessarily be overly alarmed by that. As noted, disease 'resistance' is not disease 'immunity' and conditions can conspire from time to time that make lack of any diseases impossible. Scab is encouraged by spring weather conditions that allow for lots of moisture and generally mild temperatures. It can develop one year if conditions are right and not be seen again until similar conditions recur. While it can be unslightly, it is typically more cosmetic in effect than actually harmful. Unless hit wth repeated infestations year after year that result in heavy defoliation, the tree will be fine. For many years, I grew an apple - Gravenstein, my favorite - that is prone to scab. I never ever sprayed it and while it did drop some leaves, it still managed to thrive perfectly well and produce as expected. I would make sure that all leaves are removed when they fall and raked up and disposed of in autumn as they can harbor overwintering spores. And there are countless online tutorials to guide you through a proper scab spray regime should you feel it necessary.