(Apple) [Northern Spy × Merton 793 (Northern Spy × East Malling11)] Collaborative intro of East Malling Research Stn and the John Innes Institute, Merton, England, about 1950. Technically named MM111, the MM refers to Malling and Merton.
Very popular semi-dwarf rootstock produces a tree about 65-80% of standard. Space trees 15-20' apart. No staking necessary. Slightly more precocious than standards.
Well anchored and adaptable to a wide range of soils. Resistant to woolly aphid. Prone to suckering. Not nearly as long-lived as standards. Hardy to Z4, maybe Z3.