Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, December 9, 1993 TAG: 9312080159
SECTION: CURRENT PAGE: NRV-8 EDITION: NEW RIVER VALLEY
SOURCE: JOE HUNNINGS
DATELINE: LENGTH: Medium
Apple trees now stem from specially cultivated rootstocks developed using either bud-grafting or wood-grafting techniques. Rootstocks frequently get their names from the experiment stations that developed them.
When choosing an apple tree for a home orchard, most homeowners choose dwarf varieties. Standard trees grow very large, don't bear fruit for years and are difficult to harvest because of their height.
Trees from dwarf rootstocks are generally easier to prune, spray and harvest and usually bear fruit earlier than non-dwarf types. In fact, trees from dwarf rootstocks stop growing once they bear fruit. However, some dwarf rootstocks are poorly anchored, and most require greater management than the bigger varieties.
There are a lot of dwarf rootstocks to pick from, which might make it harder to pick the one that's best for you. Each rootstock has specific characteristics that you should consider when planting a home orchard. The most important ones are:
Growth control.
Tolerance to soil and climatic conditions.
Productivity.
Tree anchorage.
resistance to disease.
The ultimate size and performance of the native tree on any given rootstock will be influenced by soil, climate, scion variety (that's the tree variety above the rootstock) and management. For example, in rich, fertile soil, all rootstocks will grow more vigorously than predicted and will need extra spacing.
The characteristics of a few of the most commonly available rootstocks are outlined below. This information should help you make an informed decision with the help of a reputable nurseryman.
\ Malling 27 (also known as M 27 or EMLA 27): This very dwarf rootstock grows to 15 to 25 percent of standard size, about 4 to 8 feet tall and 2 to 8 feet wide. It should be grown only in the best soil and needs to be staked, because it has poor anchorage.
An early-bearing variety, it's very resistant to crown rot and has limited resistance to woolly aphids; however, it's susceptible to fireblight and is not drought-tolerant.
\ Malling 9 (also known as M 9 or EMLA 9): This dwarf variety grows to 30 to 45 percent of standard size, about 8 to 10 feet tall and about as wide. It requires deep, well-drained soil, but has poor anchorage and requires staking. The resulting tree produces large fruit.
This early bearing rootstock is very resistant to crown rot, but is susceptible to wooly aphids, nematodes and especially to fireblight. It's also not drought-tolerant.
By the way, mice like this rootstock.
\ Mark (formerly called MAC 9): This dwarf variety grows from about the same size to just slightly larger than the Malling 9 and also requires deep, well-drained soil. However, it has better anchorage, though staking is probably a good idea. It doesn't tolerate drought.
The Mark exhibits resistance to crown rot and is susceptible to wooly aphids and fireblight. It bears fruit early.
This variety has been known to form root gall at the graft union.
\ M 9 (also known as MM 111): This variety grows to a height of 10 to 12 feet and also requires deep, well-drained soil. However, it has good anchorage and requires no staking. In addition, it's resistant to crown rot and wooly aphids and is drought-tolerant. It is susceptible to fireblight.
It's also quite a productive variety.
Joe Hunnings is the Virginia Cooperative Extension Service agent for agriculture in Christiansburg. If you have questions, call the Montgomery County extension office at 382-5790.
Memo: ***CORRECTION***