[IBC] Sudden Maple Death
 

Hi everyone. I had a strange and depressing thing
happen this week.

It *is* depressing. But if you want to know what caused it, you need
to look at the roots immediately, because the longer you wait, the
harder it will be to figure out what happened (people often send
maples to the diagnostic lab months after they first showed symptoms,
and we can't tell by then what happened).

So just to be safe i cut the branch off well above the
dying back section leaving space for any die back
which sometimes occurs.

That's a good plan if the plant has a blight disease, but won't help
if it has a root disease.

It did not turn black and did
not look like vertimiculum wilt, which i have run into
before.

It could be, though. You need to get a single-edge razor blade or a
good knife and shave the bark at the base of the trunk. Keep shaving
until you get to the wood, then watch as you shave, for brownish
streaks in the wood. If you sent it to me (or to a Cooperative
Extension Office) we would put a block of wood in a moist chamber and
watch to see if Verticillium grew out of the xylem vessels). Vert is
often difficult to diagnose, and the fungus disappears once the tree
has been dead for a while. Then you start picking up secondary
pathogens.

Other possibilities: look for cankers (sunken areas) on the trunk.
The tree could have been girdled by a Nectria canker, or by bark
beetles.

Do what Jim advised, and clean your tools, get rid of the corpse and
soil far away from your other trees, and keep those other trees in
peak condition. Trees can fight off Verticillium. If you live
somewhere with hot summers, heat will make one of the two species of
verticillium go dormant, and often the tree will then wall it off and
go on to be healthy.
--
Nina Shishkoff

Frederick, MD

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[IBC] Sudden Maple Death
 

Nina Shishkoff wrote:
SNIP clean your tools, get rid of the corpse and soil far away from your other
trees, and keep those other trees in peak condition. Trees can fight off
Verticillium. If you live somewhere with hot summers, heat will make one of the two
species of verticillium go dormant, and often the tree will then wall it off and go
on to be healthy.
Nina Shishkoff, Frederick, MD
====
Nina: Do you have any data on how hot and how long the heat must be there for
Verticillium to go dormant.
And is this a virus or a bacterium?
Alan Walker, Lake Charles, LA, USA
http://LCBSBonsai.org http://bonsai-bci.com

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++++Sponsored, in part, by Mike Page ++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++

[IBC] Sudden Maple Death
 

Nina: Do you have any data on how hot and how long the heat must be there for
Verticillium to go dormant.
And is this a virus or a bacterium?
Alan Walker, Lake Charles, LA, USA
http://LCBSBonsai.org http://bonsai-bci.com

Do I look like a virologist? Do I look like a bacteriologist? I do
not. I look like a mycologist, and Verticillium is a fungus.

My reference (Sinclair, Lyon and Johnson) does not give a
temperature, but says that the fungus is killed in above-ground parts
of trees in California, and survives in the [cooler] root systems. I
found a paper by some scientists in Syria who were enclosing olive
trees in plastic tents to cure them of vert, and they were using
temperatures of 30-36 C.

In bonsai, the whole plant can be heated up, and theoretically cured.
I have never heard of a nursery trying this, however. The best
treatment is prevention: buy clean stock and plant it in soil-less
media. If you don't splash infected soil around, and you use clean
tools, it will be difficult for the fungus to get into the bonsai
soil.
--
Nina Shishkoff

Frederick, MD

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++++Sponsored, in part, by Mike Page ++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++

[IBC] Sudden Maple Death
 

====
Nina: Do you have any data on how hot and how long the heat
must be there for
Verticillium to go dormant.
And is this a virus or a bacterium?
Alan Walker, Lake Charles, LA, USA
http://LCBSBonsai.org http://bonsai-bci.com

Mmm. WE qualify, Alan. ;-) So do TX, NM, AZ, S. Calif. and a
few of the lower states in the Midwest.

But it doesn't always happen. It is going to depend on how
healthy the tree is in all other respects. You will want to dose
it heavily with Nitrogen fertilizer while you're hoping it will
"wall if off."

Jim Lewis - - Tallahassee, FL - The phrase
'sustainable growth' is an oxymoron. - Stephen Viederman

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++++Sponsored, in part, by Mike Page ++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++