Monday, November 23, 2020

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

Gotta be aware when reading articles about pawpaw from other countries,
like the Australian one earlier in this thread, that everywhere else other
than North America, 'pawpaw' is generally considered to be Carica papaya,
which we call papaya.

On Mon, Nov 23, 2020, 6:12 AM Elizabeth Hilborn <ehilborn@mebtel.net> wrote:

> 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
>
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