Another species that might be looked at is Malus fusca, the native Pacific NW crab. It not only grows in water, it is reported as having the highest resistance to fireblight of all. The main problem is that is has varying compatibility with other apples. In that respect, it behaves almost like pear (and was once classified as Pyrus fusca), so perhaps using a variety like Winter Banana, which is graft compatible with pears, might work on it. Alternatively, it will hybridize readily with other apples and such natural hybrids can be found in fence rows and roadsides in many parts of western Oregon. Likely such hybrids would still be good rootstocks, but with better graft compatibility.|
Also, any species that is used as a rootstock should be better explored. Pyrus betulafolia is considered an excellent pear rootstock, but the main material used is from the southern part of the range and is not very cold hardy. There are forms from the northern part that are hardy to more than -40 and are small plants, with potential to be good dwarfing stock. I have a bit of this and trees over 12 years old are no more than 8 feet tall. In fact, most of the population I have are more shrubs than trees.
Grapes, unusual fruits, writing, consulting, more, at http://www.hevanet.com/lonrom
From: jim <firstname.lastname@example.org>
Subject: Re: [nafex] Malus prunifolia
Date: Sat, Dec 9, 2000, 4:23 AM
2) If we look at the geographical distribution of the species, it's easy to judge that one should not generalize from a single or even several samples. Malus prunifolia is evidently endemic across an extremely wide belt, from eastern Siberia nearly to Lapland. The north-south distribution is also quite extensive. Within that wide distribution there must be an enormous variation in characteristics. To further complicate matters, there has been constant hybridization along the contacts with other Malus species. We have no way of knowing whether a particular lot of Malus prunifolia seeds came from Vladivostock or from the northern Urals or maybe from half a dozen hybrid trees in the Warsaw Botanical Gardens.
3) We do know that within the species we can find resistance to fire blight (although there is no evidence that the species in its natural habitat was ever exposed to Erwinia), immunity to apple scab, non-preference resistance to voles, and a lot of tolerance for low winter temperatures. The Cornell-Geneva 'Novole', which carries those 3 resistances, comes from a Malus prunifolia x Malus sieboldii cross.
My bottom line: I wouldn't touch Malus prunifolia with a 10ft pole for rootstock purposes unless I knew a great deal about the characteristics of the particular seed lot.
Del (ando others interested)
I just did a search on prunifolia and did find that one site
(garden. . . something or other) did say that it does well on heavy
This makes me wonder Del, what did the roots look like, were they
more carrot shaped or fibrous?
It said that prunifolia also does well under drought conditions, and
is frost tolerant.
I would like to learn more about malus prunifolia, anyone out there
used it as a rootstock? Lawyers used to offer it but not lately.
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