| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | Mark |
An open-pollinated seedling of M.9 and introduced by Michigan state University, USA in 1979. It is a virus-free clone of MAC-9. Mark is a hardy, precocious dwarfing rootstock. It is susceptible to fire blight and fairly resistant to crown and root rots, produces many burr knots and few root suckers. Mark requires tree support. Trees are very precocious and tree vigor may decline earlier than desired when young trees are allowed to produce heavy crops |
Apple Rootstock Info: MM.111 EMLA
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | MM.111 EMLA |
Introduced in 1952 from a cross of Merton 793 x ‘Northern Spy’ by the John Innes Horticultural Institute and the East Malling Research Station in England. MM.111 EMLA is one of the more vigorous semi-dwarf rootstocks, producing a tree about 85 to 100% the size of seedling. It is resistant to wooly apple aphid and is quite tolerant to fire blight and crown and root rots. It is fairly winter hardy and produces moderate |
Apple Rootstock Info: MM.106 EMLA
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | MM.106 EMLA |
Selected in 1932 from a cross of M.2 x ‘Northern Spy’ by the John Innes Horticultural Institute and the East Malling Research Station in England. MM.106 EMLA is a semi-dwarf rootstock, producing a tree about 60% the size of seedling. It is quite precocious and productive and usually does not need tree support. It is resistant to wooly apple aphid, but is highly susceptible to crown and root rots, susceptible to fire blight, and |
Apple Rootstock Info: M.27 EMLA
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | M.27 EMLA |
Selected in 1934 from a cross of M.13 x M.9 at East Malling Research station in Maidstone, Kent, England and was tested as Malling 3431. M.27 EMLA is a very dwarfing rootstock and is probably too dwarfing for most commercial situations except for vigorous cultivars on vigorous sites, but it might be considered for home gardens where a small tree is desirable.. Trees on M.27 EMLA are very precocious and productive and require permanent |
Apple Tree Viruses
Virus and Other Graft-Transmissible Diseases and Disorders of Apples
Virus diseases cause economic losses through lower yields and reduced quality of apples and apple products. In general, virus diseases in perennial crop plants, such as apples, are more potentially damaging than in annual crops. Viruses can remain latent, spreading through an orchard and inflicting damage, often without the growers’ knowledge. Latent virus infection can produce small to moderate losses in fruit production. Often growers can maintain the productivity of diseased …
Apple Rootstock Info: M.7 EMLA
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | M.7 EMLA |
Formerly known as EM VII. Selected in 1912 from unknown parentage at the East Malling Research station in Maidstone, Kent, England. Trees on M.7 EMLA produce a semi-dwarf tree about 60 to 70% as big as seedling. Trees are moderately precocious and may lean with some cultivars and may require trunk support. Trees tend to produce many rootsuckers. M.7 EMLA has been widely planted since the 1960s with cultivars such as ‘McIntosh’, ‘Empire’, ‘Cortland’, |
Apple Rootstock Info: B.9
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | B.9 |
Resulted from a cross of M.8 x ‘Red Standard’ (Krasnij Standard) from Russia. B.9 has been tested widely and is used commercially in the U.S. In general, B.9 is slightly more dwarfing than M.9 and has slightly higher yield efficiency than M.9. B.9 was selected as a dwarfing cold hardy rootstock and initial inoculation results indicated that it was as susceptible to fire blight as M.9. However, in field trials, trees grafted onto B.9 survived |
Apple Rootstock Info: Ottawa 3
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | Ottawa 3 |
Introduced by the Agriculture Canada Research Station in Ottawa, Ontario, Canada in 1974 as a hardy dwarfing rootstock. The parents were M.9 and ‘Robin’ crab. Ottawa 3 roots poorly in the stoolbed and is often micropropagated. Trees are precocious and produce few rootsuckers and burrknots. It is sensitive to apple stem grooving virus. Ottawa 3 was included in the 1990 NC-140 cultivar/rootstock trial at 12 locations and the 1990 dwarf rootstock trial at 8 |
Apple Rootstock Info: P.2
| Characteristic | Detail | Description |
|---|---|---|
| Rootstock | P.2 |
Resulted from a cross of M.9 x Common Antonovka and released by the Research Institute of Poland in Skierniewice, Poland. This is a productive, cold hardy, dwarfing rootstock slightly more dwarfing than M.9 NAKBT-337. It is susceptible to fire blight, and wooly apple aphid, but fairly resistant to crown and root rots. It produces few root suckers and burr knots similar to M.9. In NC-140 trials trees survive; depaending on location tree size was similar |
How Apple Tree Productivity Is Measured
The simplest approach to measuring productivity is to assess yield on a per-tree basis; it is straightforward and easy to understand. The problem comes when comparing trees of different sizes. For instance, comparing the productivity of apple trees on M.9 NAKBT337 and those on G.30 on a per-tree basis would be meaningless. The size of trees on M.9 NAKBT337 would allow much greater planting densities than would that of trees on G.30. Therefore, trees on M.9 NAKBT337 could have a …