The point of using an interstem is to get dwarfing and precocity from the interstem while having a more vigorous rootstock that will provide you with a better anchorage and a little more size.

The vigor a 111 rootstock with an M26 interstem is something in the middle of the 2 and trees with this combination produce fruit almost as quickly as a tree on M26.

I don't quite understand the point of your project, as seedling anything will have unpredictable vigor and precocity. How can you evaluate cause and affect?

Harvestman Thanks. I didnâÂÂt want to ask but I was hoping some the more experienced growers like you would add to the limited knowledge that I have. Over the last six months I have enjoyed reading your post and others. I often wonder if you realize what a source of experience and knowledge you serve for people like me. The plants that IâÂÂm starting now are on M111 rootstock. I guess its debatable but it appears to be the best all round stock for me. Good or bad sometimes I just try different things without an exact outcome expected. IâÂÂm one auburn grad that loves tinkering with plants but has just enough knowledge to be dangerous. Thanks again.

Now that I look at your photo I see what you are actually trying to do. You want to make use of the rootstocks you started with but end up with a tree that doesn't require too much space or time to bare. Right?

The experiment in this context makes perfect sense to me- sorry I didn't look closer to begin with.

You won't know the exact affect of the interstem (what is it?) but you can be sure it will cause some dwarfing, unless the seedling somehow is a dwarf itself.