North American Fruit Explorers mailing list at ibiblio

[John Barbowski <jbarbowski@gmail.com>]

Doing a bit more work, the malady may be caused by the fungus
Botryosphaeria obtusa - commonly known as 'Black Rot Canker'. "Northern
Spy, Cortland, Gala, Honeycrisp, McIntosh and Empire are most often
infected, although all apple cultivars are susceptible." (ref
http://www.omafra.gov.on.ca/english/crops/facts/blackrot.htm )

I am near the extremity of the cold tolerance for Cox's Orange; this may be
a contributing factor. My tree's location was in partial shade (3 PM on)
and was also competing with a neighbour's large Norway Maple 15 feet away.
I have previously notice the maple's shallow roots infiltrating my area.

I will re-graft the species (my wife's favourite). I have scions available
on another tree and will plant it in a sunnier location.

Thanks for the responses.

jmb

On Tue, May 3, 2016 at 10:47 AM, Matt Demmon <mdemmon@gmail.com> wrote:

> John,
>
> I cannot remember the name of this disease, and my reference book is packed
> away right now, but this looks like something that was affecting my apples
> and pears after several wet cool summers in a row. I think it came in with
> a new pear tree. From my memory, it's a fungal disease that affects apples
> and pears only, and something I had never heard of before I got it, but I
> looked it up in a disease book and was 95% sure I had the ID right. The
> bark splits, there is brown discoloration, and it's kind of soft and moist.
> Only cure I think was to cut it out well back of any affected spots, burn
> it, and hope.
>
> Sorry I can't remember the name! I found it in a book put out by the
> extension here.
>
> -Matt
> SE MI, zone 5-6
>
>