Geneva 41 touted as best apple rootstock
In this months Good Fruit Grower, Geneva 41 is touted as the best apple rootstock. It is resistant to fire blight and replant disease, and I think wooly aphid. It's also cold hardy, precocious, high yielding and about M9 size. Only problem has been propagation.
M111 and 106 don't crop annually and produce small fruit.
M7 is called a weed and falls over. It root suckers badly.
M9 is the worldwide standard with over 100 clones that vary from 25 to 50% the size of standard. It bears young, has large fruit, and yields heavily every year. It is Fire blight susceptible.
M26 is highly variable in vigor and fb susceptible.
Mark is the standard for precocity and gives high yields.
Geneva 11 is about like M9 but with resistance to fb and crown rot.
Geneva 16 is about like 11 but highly sensitive to viruses.
Bud 9 is sized like M9 but with fb resistance.