Most commonly planted apple rootstock in Kentucky. Resistant to crown rot and fire blight. Tends to be thorny and difficult to work with in the nursery. Recommended for trial in Kentucky. Consistently a highly productive rootstock, second only to M.9 in efficiency.
Suckers are few.
Its susceptibility to collar rot restricts its usefulness in Kentucky. Resistant to woolly aphid. Should not be planted on sites that tend to have poorly drained soil. Trees of Red Delicious and some other varieties on MM.106 are susceptible to union necrosis and decline, which is caused by tomato ringspot virus. Semi-vigorous, but more drought tolerant, somewhat better anchored and slightly more productive than other rootstocks.