Re: [nafex] Elizabeth's grafted pawpaw sudden death

Thank you Patsy.

I does almost seem like graft incompatibility, the way it has manifested
among so many different trees and different time periods. But the
rootstock is apparently from different places: I have purchased the
trees from four different vendors, East and West coasts (Oregon,
Virginia, Maryland, Kentucky).

I need to get busy with scionwood this spring, I have so many dozens of
seedlings/ sprouts now. It will be interesting to see what happens.

Thank you for your thoughtful reply.

Yes Ambrosia beetle. I had attacks on two grafted Chinese Chestnuts
about 12 years ago. Very dramatic- covered with tiny tubes of
frass/sawdust  on 2 inch caliper trunks. Cut and burned those trees.
What a waste.

On 11/23/2020 12:20 AM, Patsy King wrote:
> I know nothing about pawpaws but wondered about graft incompatibility. A
> google search brought up this response to somebody whose trees die in the
> fall: (I put bold formatting on the pertinent part):
> Several possibilities come to mind for the cause of your trees death.
> Pawpaws require a well drained soil and we have had two wet seasons back to
> back. Saturated soils make trees much more susceptible to Phytophthora root
> rot. If the roots are dead this is probably the cause. This particular tree
> may have been growing in an area where water pockets after a rain or in a
> drainage area. *If the tree is a grafted one and the roots are alive (You
> can cut through the bark with a knife and see green tissue), but the top of
> the tree is dead the problem could be graft incompatibility with the
> seedling rootstock. This can show up a number of years after planting.*
> There is not much that can be done about this other than plant another
> tree. Alternatively if you look very closely at the dead top of the tree
> and see a multitude of pin head sized holes with what looks like a
> toothpick sized extension from the hole of sawdust the problem is Ambrosia
> beetle. This insect attacks trees that are growing less rapidly or are
> stressed. A targeted spray program for this insect is needed if this is the
> problem.
>
> The URL of the info above is:
> https://ask.extension.org/questions/293442
>
> <https://ask.extension.org/questions/293442>
> I found more fascinating info here, mentioning that pawpaws usually are not
> grafted, and why. But it does tell how the writer did the grafting when he
> tried.
> http://rarefruitclub.org.au/Level2/GraftingPawpaws.htm
>
> Were your grafted trees all purchased ones? I was not able yet to find
> out in some quick googling, what rootstocks/scions to use in order to avoid
> graft incompatibility.
> __________________
>

--
Elizabeth Hilborn, DVM
Bee Well Mobile Veterinary Services, PLLC
beewellvet.com

__________________
nafex mailing list
nafex@lists.ibiblio.org
Northamerican Allied Fruit Experimenters
subscribe/unsubscribe|user config|list info:
https://lists.ibiblio.org/mailman/listinfo/nafex