North American Fruit Explorers mailing list at ibiblio

["del stubbsrockyman" <pinewoodel@hotmail.com>]

Derry, thanks very much for such an extensive and valuable resource from 
your rootstock book, difficult stuff to find!      the word precocious 
appears a great deal in fruit tree discussion.  does it mean exhuberant 
growth early in its life or each year or just what?  thanks again            
                        minnesota del

>From: "dwalsh/wchase" <wchase@interchange.ubc.ca>
>Reply-To: nafex@egroups.com
>To: <nafex@egroups.com>
>Subject: Re: [nafex] Tender rootstocks
>Date: Sun, 3 Dec 2000 10:17:29 -0800
>
>Del,
>
>I don't know anything about rootstock hardiness (coming from rainy PNW), 
>but I am
>just reading a book Rootstocks for Fruit Crops by Roy C Rom and Robert F 
>Carlson.
>1987 and I've scanned the chapter on hardiness.
>
>As far as I can see there is no mention of Malus prunifolia.  They do 
>mention M
>baccata and M robusta, but usually in reference to breeding programs.   
>(Rom is
>from U of Arkansas and Carlson is from Michigan State U )
>
>Chapter 4 Rootstocks by David Ferree and Robert f Carlson
>
>  3.2. Rootstock Adaptation to Climate
>
>Hardiness. There are genetic differences among apple rootstocks in cold 
>hardiness.
>Generally, however, in the principle apple-producing regions of North 
>America, the
>commonly used Malling and Malling Merton rootstocks have proved 
>sufficiently
>winter hardy for commercial use. In an occasional test winter, especially 
>in areas
>of more extreme temperature fluctuations like the Great Plains, mortality 
>of the
>rootstocks has occurred.
>
>In New York State, field nursery observations following air temperatures of 
>-31
>to -34°C revealed a relatively more hardy group of rootstocks (M.1, M.2, 
>M.3, M.4,
>M.5, M.7. M.12, and M.16), a relatively less hardy group (M.9 and M.13), 
>and a
>group not hardy at these temperatures (M.6, M.8, M.10, and M.15). In 
>western
>United States and Canada, Delicious on M.7 survived -44°C, while trees on 
>M.2
>showed severe injury. In other cold-hardiness trials, Ottawa 4, Ottawa 3, 
>MM.106,
>and C52 have been tolerant of -35°C but intolerant of -40°C.
>
>Predisposition of rootstocks may affect their response to cold 
>temperatures, for
>example, M.26 has appeared to be very cold hardy in some tests and 
>relatively
>sensitive in others. Roots discernible at the soil surface and arising from
>burrknots or nodes on M.26, M.27, MM.106, and CG.10 have been killed at
>approximately -15°C. Unfortunately, this type of injury may serve as 
>infection
>sites for root-rotting fungi. Factors such as previous crop load and 
>temperatures
>leading up to the extreme may be equally important in determining ultimate 
>injury,
>and these factors no doubt account for much of the variability among 
>rootstocks.
>
>Fruit-producing areas of the world subject to extremely cold winter 
>temperatures
>have served as rootstock cold-hardiness test sites. In Poland, in a test 
>year
>without snow cover, and with a soil temperature of -11°C at a depth of 5 
>cm,
>nearly 75% of trees on M.9 were killed, while only 15-20% of trees on M.26 
>and
>Bud.9 were killed. The Polish rootstocks P.2 and P.22 were as hardy as 
>Antonovka
>seedlings and retained considerable hardiness during fluctuating warm and 
>cold
>periods. In Minnesota field studies that purposely removed snow from test 
>sites,
>the rootstocks M.7, M.9, M.26, MM.104, and  MM.106 were hardy at -18°C. 
>Both
>root-freezing tests and field observations indicated that M.26 was more 
>hardy and
>M.7 less hardy than the other clones.
>
>Winter-hardy cultivars have been used as rootstocks and as trunk and 
>scaffold
>systems for less hardy cultivars. During a test winter in Washington State 
>with
>temperatures of -44°C, Robusta 5, Antonovka, 'Hibernal', and 'Red 
>Astrachan'
>survived and demonstrated more cold tolerance than scaffold systems of 
>'Mcintosh',
>'Delicious', 'Haralson', and 'Canada Baldwin' . Apparently in addition to 
>the
>hardiness provided by the trunk stock itself, some hardiness can be 
>imparted to
>the scion cultivar by 'Hibernal'. In Oregon during a November freeze of 
>-18°C,
>trunk stocks of 'Transparent', 'Hibernal', 'Haralson', 'Canada Baldwin',
>Antonovka, 'Charlamoff', and 'Hyslop Crab' prevented tree crotch and trunk 
>injury.
>Lapins classified the hardiness of various frame builders as follows: Very 
>Hardy:
>'Anis', 'Charlamoff', 'Heyer 12', 'Hibernal'; Hardy: Antonovka, 'Beautiful
>Arcade', 'Borovinka', 'Duchess', 'Haralson', Malus robusta No. 5, 'Robin', 
>'Yellow
>Transparent'; Moderately Hardy: 'Anoka', 'Canada Baldwin', 'McIntosh', 
>'Melba',
>'Red Astrachan', 'Winter St. Lawrence'.
>
>One of the most important ways that rootstocks can influence hardiness of 
>the
>scion cultivar is by speeding maturity in the fall and delaying budbeak in 
>the
>spring. Rootstocks that induce early maturity of the scion, such as M.9 and 
>M.7,
>tend to protect trees from fall freezes, but this may not relate to 
>protection
>against midwinter cold. M. 1, M.4, M5, and M.7 have been shown to attain 
>cold
>hardiness nearly two months earlier than M.2, which is most cold sensitive 
>early
>in the autumn
>
>Several rootstocks, such as M. 13 or M.16, when left to develop into 
>fruiting
>trees, bloom as much as two weeks later than the bloom of most commercial 
>apple
>cultivars. However, the time of bloom characteristic apparently isn't 
>conveyed to
>the scion, as scions on these stocks generally bloom at their normal time. 
>Another
>factor to be considered is precocity, or the earliness in the life of the 
>tree
>that flowering begins. 'Northern Spy' is notoriously tardy, as a cultivar, 
>to
>begin flowering and fruiting. However, as a rootstock, it tends to induce
>precocity similar to seedling rootstocks. M.9 tends to be precocious both 
>as a
>scion and rootstock, and as a rootstock induces precocity in the scions. 
>Thus it
>appears that the flowering characteristics of a given clone cannot be 
>predicted to
>have the same influence as a scion as when the clone is used as a 
>rootstock.
>
>
>p 111. Texture. In whole-tree excavation studies, Rogers and Vyvyan found 
>that
>depth of rooting increased from sand to loam to clay. In loam and sand, the 
>root
>system had the same general conformation - a shallow scaffold with 
>vertically
>descending roots. While in clay, most roots sloped downward and grew in the
>subsoil. The total amount of root/tree was greatest in loam soils, followed 
>by
>clay, with the least amount of root in sandy soils. On all soil types, 
>roots
>spread farther than the branches, and in sand, root spread was 2 to 3 times 
>branch
>spread, but in loam and clay, it was only 1 to 1.5 times. In sand, roots 
>were
>long, thin, straight, and spreading, while in clay the roots were fairly 
>short,
>tapering, rapidly branching, and twisting in all directions. In the loam, 
>the
>roots were intermediate in appearance between those in sand or clay. The
>rootstocks grown in these various soil types maintained their unique 
>character
>with only slight changes on various soil types. For example, on the sandy 
>soil,
>depth of rooting was greatest for the experimental rootstock (DF5) and 
>least for
>M.9 and M.1, while on the loam, M.9 had the deepest roots.
>
>Hope this helps the discussion,
>
>Derry
>
>Derry Walsh & Bill Chase  email:wchase@interchange.ubc.ca
>Aldergrove,  B. C.,  Canada
>phone/fax (604) 856-9316
>~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
>Home web page  http://www.interchange.ubc.ca/wchase/HTML
>~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
>Sent: Saturday, December 02, 2000 9:01 PM
>Subject: Re: [nafex] Tender rootstocks in zone 3
>
>
>im ignorant on the subject of cold tolerance as relates to
>: soil type. We're on hilly heavy clay, ( 340' deep to be exact! having had 
>a
>: well dug)   i dont know where there is a snow belt in this area, last 
>year
>: we looked at grass all winter-sad skis., so i guess any slightly tender
>: trees would have been snuffed.  so far i have 100 apples ive grafted onto
>: malus prunifolia. What is anyones opinion about it and its use in heavy
>: soil?   i heard its one of the origional 4 apples, true?    any knowledge 
>of
>: its origin location? i was taught to graft just below the soil line, for
>: varietal regeneration , but is this advisable  in heavy soil
>thanks, minnesota del
>:
>
>

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