brandon,
See the linked article below.

I'm in agreement with the author that you really need to select rootstocks(at least so far as apple & pear are concerned - stonefruits are a different critter) based on anchorage, disease resistance etc., rather than on 'size control'. Ultimately, YOU are in charge of how large(or not) your apple tree becomes; Prune, Prune, Prune.

That said, I've planted, over the past 15 years, 60 or more apples, on various semi-dwarfing rootstocks - M7, M111, M111/M9, M106, and some unknown to me. Of all these, M7 has been the best, most reliable performer. All sucker fairly profusely, but M7 perhaps a bit less than M111. M111 and the combo M111/M9 have failed to anchor in my good clay soil, exposed windy site - many of those trees would be lying flat on the ground, except for my having propped them up. Trees on M106 have been exceedingly slow to come into bearing.

Personally, I wouldn't want an apple on a standard rootstock - the average person would have immense difficulty pruning/spraying/harvesting fruit from them. A semi-dwarf or even some of the better-anchoring dwarfing rootstocks are probably a better choice.

Here is a link that might be useful: Dwarf Tree? But it's so BIG!

111 is long-lived and adaptable. The burr-knots are just clusters of root primordia and have never been an issue on trees in my region. M7 used to be my choice but poor anchoring tendoncies are a nuisance and 111 is generally more conducive to survival under relative neglect. The root-stock will not affect mildew susceptibility.

I'm curious if anyone else out there has found burr-knots to be a meaningful liability. What works here may not work so well elsewhere but I have often heard and read experienced southern growers extolling the virtues of 111.

You forgot to mention domestic apple seedling with the vigorous rootstocks. The reason seedling and other vigorous rootstocks (Northern Spy used to be the benchmark) are so long-lived is that they basically outgrow whatever's trying to attack them. The roots are vigorous and thus extract nutrients and water from a larger area, and the roots have a tough, rope-like strength to them (as opposed to thin brittle roots of dwarfing rootstocks). The canopy is capable of growing new limbs if snow or bears break off one.

It is not uncommon for a seedling tree to take 7-10 years to really start bearing. But even semi-dwarf trees from M7 upward have a chance of outliving you. On the other hand, I'm thankful for the pioneers that planted our local mountains with seedling rootstock trees 100 years ago so we can still go pick a bunch of apples. I say plant both; maybe a Geneva dwarfing rootstock resistant to fireblight and a seedling tree that will outgrow the fireblight...

Brandon, Gardenweb hasn't deleted the older posts, yet. There's a glitch in the upgrade they just did that for some reason won't display the older posts using a simple forum "Search". It's very frustrating, because there's a lot of valuable information there
However, if you do a Google search on "gardenweb.com/forums/fruit/"; and then the title of the post that had the "Whoops-" message, the page with the message comes right up. You can click on it and read it.
I sure hope they can fix this without deleting the older posts.

I manage plenty of apple trees on size reducing rootstock that are well over half a century old with no signs of decline. They haven't dropped off in the production of high quality apples either.

Some home orchardists sanitize their pruning tool between every cut, or every job or whatever they consider appropriate.

How do you know if the owner practices some form of hygeine that your unapproved pruning will violate? What if they are trying to train the tree in a particular manner? How would you know any of this?

What if he's grafted the last stick of his great grandfather's dying tree onto the tree in question and you harvest it off, or inadvertantly damage it during your gathering?

What if a homeowner has several newspapers piled up on the doorstep. They appear to be unwanted, is it OK for you to take them? How many need to be piled up before its OK and how many can you take? What if the owner is saving them for mulch or paper mache and just hasn't bothered to collect them up yet?

I've been tempted to "prune" the trees from the local big box hardware store, but it was so obviously wrong that I didn't do it. If I did so it wouldn't because I thought it was moral or ethical, it would be because I'd succumbed to temptation.

Yo Murky,

You got the wrong thread man!

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Everyone Else,

It's interesting how M 7 and M 111 have produced opposite results for different growers. Can this really be simply from different environments/soil types?

I've seen the technical difference in M 111, MM 111, and EMLA 111 written out, but is there really much of a difference in actual practice?

Anyone else have opinions about burr knots? I have read that they are frequently an entry point for various insects and borers, which in turn leads to all kinds of problems. I also read today that burying the graft union was not only a disadvantage because, in many cases, the advantages of the rootstock would be voided, but also because collar rot was much more likely.

I now see that tomato ringspot virus is also a problem with 111. Tomato ringspot virus can lead to apple union necrosis and decline. Is this problem widespread? Is there a solution?

BTW, I really appreciate you guys taking the time to answer my questions! It is very helpful to get feedback from actual growers.

Oops, sorry. I wonder what happened to my post.

Sometimes I have several gardenweb windows open at once. They load slowly so I'll "open in new window" each thread with an interesting title.

This is the first time I've posted in the wrong thread. Hopefully I'm not slipping.

You may now return to your regularly scheduled programming.

Aren't there any commercial or serious amateur growers in your area you can ask? I know that nurseries all over the country sell trees on emla 111 (virus free). You can certainly plant the trees right to the graft union, 111 won't rot from contact with soil. You can also contact your cooperative extension for suggestions.

There are orchards in Tennessee, but no large ones near where I live. I have seen small plantings (10-15) trees around some of the local farms, but would be surprised to find that those growers were "experts". In any event, I don't know any experienced individual fruit growers locally.

It seems to me that feedback from multiple sources, such as here on Gardenweb, is one of the best ways to get info. Another good thing is the "peer review" that goes on here. I have talked to the local extension people, but have found that the amount of helpful information from them is definitely limited. I think the combined years of experience here are probably highly useful compared to any single source with which I am familiar.

As for planting the graft union right at ground level, from what I read about burying the graft unions to reduce/eliminate burr knots, I'm not sure that planting the graft unions at or just above ground level would work. I think the idea was to plant the trees so that the scion would form its own root system and eventually bypass the 111 rootstock. Has anyone else had good or bad experiences with 111 concerning burr knots?

Anyone have any information about how much difference the EMLA (virus free) rootstock makes?

How about the tomato ringspot virus issues?

EMLA is usually all that's available from repuatable nurseries these days, at least the commercial suppliers. Virus free may or may not make a noticable difference, I have even heard of a variety being better on a dirty rootstock but I don't really take that seriously. I would go for EMLA but don't assume that a nursery is selling something else because they don't label it as such.