Agriculture Reference
In-Depth Information
pressure is low. Problems with brittle roots and poor anchorage on M9 have
been reported. A more cold-hardy and disease-resistant replacement is
Bud-
agovsky 9 (Bud9)
, which also tolerates heavier soils better than other root-
stocks in this size range.
Nic29
is a new M9-type rootstock from Belgium
that, reportedly, produces a better root system and is stronger and more vig-
orous than M9 but still produces adequate dwarfing. Trees on Nic29 require
support. Avoid the 'Mark' rootstock, which has proven susceptible to diseases
and winter injury.
The
M26
rootstock has been widely popular, but its susceptibility to root
rot and fire blight limit its value. Consider using
Geneva 11 (G11)
or
Bud9
instead of M26. For cold climates (Zone 3), consider
VinelandV2
and
V7
root-
stocks, which are fire blight-resistant and produce trees toward the tall side
for this range. The
Polish P2
rootstock is similar to M9 and reported to be
very cold-hardy.
Ranetkacrab
seedling rootstocks are very cold-hardy and drought-resistant,
and they grow well and produce good-sized fruit. These rootstocks re-
portedly survived a week of −40°F (−40°C) temperatures with no snow cover
in Fairbanks, Alaska, but their compatibility with many apple varieties has
not yet been reported.
The above rootstocks should support all but the most vigorous apple vari-
eties. While early bearing is desirable, beware of overbearing, especially on
very young trees. Plan on an aggressive fruit thinning program.
Medium-Sized Trees (10 to 16 feet tall)
Trees that are 40 to 65 percent of the standard size are valuable for freest-
anding or vertical axis systems. The
M7
rootstock and its virus-free version,
EMLA7
, have long been popular and remain fair choices, except when used
with 'Red Delicious' strains and 'Idared'. They are quite winter-hardy and per-
form best on deep, well-drained soils. Trees on M7 rootstock can benefit from
being staked for the first 4 or 5 years after planting.
