Subject: Grafting: reasons for incompatibility?

From: [email-masked] (Bernd Hardeweg)
Date: Tue, 03 Dec 1996 14:38:35 GMT

Does anyone have any hypothesis about physiological reasons for
incompatibility between rootstock and graft in fruit tree growing?

Why do e.g. combinations with dwarfing cherry rootstocks often die
after several years of normal growth?

thanks

Bernd Hardeweg

email: [email-masked]
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From: Larry Arsenault <[email-masked]>
Date: Sat, 7 Dec 1996 15:30:36 -0800

I'm no expert, but I have heard that the type of graft matters in that if
there is ANY "air"  in the graft, even though the scab appears strong, the
tree dies off after several years.  I've been using a cleft graft with
some success - so far - and a common graft.  Three years and all's well...

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From: [email-masked] (Anne Gillen)
Date: 11 Dec 1996 05:59:48 GMT

Bernd Hardeweg ([email-masked]) wrote:
: Does anyone have any hypothesis about physiological reasons for
: incompatibility between rootstock and graft in fruit tree growing?
: 
: Why do e.g. combinations with dwarfing cherry rootstocks often die
: after several years of normal growth?
: 
: thanks
: 
I once went to a seminar by someone who studied this.  I
cannot remember his name.  He worked for the United States Department
of Agriculture (USDA).  He though that there was no one reason why grafts 
fail.  I do not remember details.  He seemed to think that variation
in enzymes was important.  He studied ornamental trees, not fruit trees.
Perhaps if you look up maple or oak and graft incompatibility on a
database you will find some ideas.

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From: [email-masked] (Scott Arighi)
Date: Fri, 13 Dec 1996 00:49:06 GMT

>> after several years of normal growth?

One reason that has been suggested for graft incompatibility is virus
infections in, particularly, the scion wood.  
--
Scott Arighi

Those who ignore history are doomed to repeat it.

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From: [email-masked] (Russell Nelson)
Date: 13 Dec 1996 16:04:50 GMT

> after several years of normal growth?

I've been told that dwarfing rootstocks are not as hardy as normal
rootstocks.  Depending on where you are in Germany, and your
microclimate, the rootstock might just be too wimpy.

-- 
-russ <[email-masked]>    http://www.crynwr.com/~nelson
Crynwr Software sells network driver support    | PGP ok
521 Pleasant Valley Rd. | +1 315 268 1925 voice | The more corrupt the state,
Potsdam, NY 13676-3213  | +1 315 268 9201 FAX   | the more numerous the laws.

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From: [email-masked] (Rick Young)
Date: Sat, 14 Dec 1996 14:35:05 -0800

> after several years of normal growth?

I am interested in growing dwarfed cherry trees in a cordon and I am
interested in any information others may have regarding dwarfing
rootstocks,

Last year I tried to purchase some cherry trees on dwarfing Giessen
rootstock from Raintree Nursery (Northern California, USA). I was confused
about what was said in a conversation with their sales man at that time
and I may not recall all the details correctly, so please do NOT consider
this to be accurate.  The sales person indicated that some how the
rootstocks were susceptible a blossom blight, a disease transmitted by
insects through the flowers.  So, the trees would get the disease only
after they started to flower, it would enter the tree through the flower,
but kill the rootstock.  He discouraged me from purchasing trees on that
rootstock.

I have not seen any other information to support this. They were offering
Gisela (Giessen)148-8 rootstock (in 1995) and seem to have switched to
Gisela (Giessen) 148-2 this year.  At the moment, I can't find last years
catalog, so I can not verify that the 148-2 rootstock was the one that was
offered last year and had the problem described above.

- Rick