I have a small dendrobium antennatum in a 6 inch clay pot. It is growing
well and looks healthy by all observations. I find the leaves have a black
sooty mildew particularly on this years growth. The are no critters on them
or ever have I seen anything on this plant.

My guess is that it exudes some sort of sap that is causing this. Anyone
else see this on this lovely plant?

I've tried cleaning the leaves with a damp paper towel but it is boring slow
work. Any ideas on how to prevent this on further growth?

The only time I've seen anything resembling this is when there were scales
in the area. Not the case this time.

Good Growing,
Gene

Gene,

I hope I'm wrong here, but sometimes such sooty deposits are a precursor to
a scale infestation (or is it mealies?).

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Artwork, Books and Lots of Free Info!


"Gene Schurg" wrote in message
news:eQtbf.10386$Q27.5937@trnddc02...
I have a small dendrobium antennatum in a 6 inch clay pot. It is growing
well and looks healthy by all observations. I find the leaves have a
black
sooty mildew particularly on this years growth. The are no critters on
them
or ever have I seen anything on this plant.

My guess is that it exudes some sort of sap that is causing this. Anyone
else see this on this lovely plant?

I've tried cleaning the leaves with a damp paper towel but it is boring
slow
work. Any ideas on how to prevent this on further growth?

The only time I've seen anything resembling this is when there were scales
in the area. Not the case this time.

Good Growing,
Gene

I hope I'm wrong here, but sometimes such sooty deposits are a precursor
to a scale infestation (or is it mealies?).

The memory is foggy, but I'm pretty sure that someone on this board recently
wrote that boisduval scale is often preceded by sooty stuff. I'd spray the
plant with alcohol to kill off the mildew, anyway.

Diana

Around here, we call this "sooty mold." We don't consider it a serious
problem, but it is at best unsightly, so we try to get rid of it. So far, a
peroxide wipe seems to be the easiest way, for most plants. Kenni

"Gene Schurg" wrote in message
news:eQtbf.10386$Q27.5937@trnddc02...
I have a small dendrobium antennatum in a 6 inch clay pot. It is growing
well and looks healthy by all observations. I find the leaves have a
black
sooty mildew particularly on this years growth. The are no critters on
them
or ever have I seen anything on this plant.

My guess is that it exudes some sort of sap that is causing this. Anyone
else see this on this lovely plant?

I've tried cleaning the leaves with a damp paper towel but it is boring
slow
work. Any ideas on how to prevent this on further growth?

The only time I've seen anything resembling this is when there were scales
in the area. Not the case this time.

Good Growing,
Gene

I've been watching this plant for the entire summer. The black crap has
been there all summer and there has been no scale or mealies. That was the
first thing I thought and I've checked it many times.

As Kenni said it's mostly makes the plant look "dirty" but doesn't seem to
bother the health of the plant.

I'll wipe it off but as the plant grows larger this will be more of a
problem keeping it looking good. What about Physan? Would it hurt if I
sprayed the plant to kill the mold? Is it mold?

Thanks for the replies,
Gene

Gene Schurg wrote:
I've been watching this plant for the entire summer. The black crap has
been there all summer and there has been no scale or mealies. That was the
first thing I thought and I've checked it many times.

As Kenni said it's mostly makes the plant look "dirty" but doesn't seem to
bother the health of the plant.

I'll wipe it off but as the plant grows larger this will be more of a
problem keeping it looking good. What about Physan? Would it hurt if I
sprayed the plant to kill the mold? Is it mold?

Thanks for the replies,
Gene


Gene, what is above the plant? Are there other plants up higher?
Anything from other orchids to a shade tree? Black sooty mold is usually
from something dripping down from above, but it could be growing on sap
from within your plant as you suggest.
Before I did anything else, I would take the plant to a sink and get my
hands real soapy (dish soap is fine) and massage every leaf and
pseudobulb until it's all soapy and clean. Rinse all the soap completely
off. This should get rid of the mold, get rid of what the mold is living
on, and get rid of any microscopic critters that may (or may not) be
contributing to the problem.

Steve

Nothing but glass is above this plant. It must be caused by something being
exuded from the leaves.

Gene


"Steve" wrote in message
...
Gene Schurg wrote:
I've been watching this plant for the entire summer. The black crap has
been there all summer and there has been no scale or mealies. That was
the
first thing I thought and I've checked it many times.

As Kenni said it's mostly makes the plant look "dirty" but doesn't seem
to
bother the health of the plant.

I'll wipe it off but as the plant grows larger this will be more of a
problem keeping it looking good. What about Physan? Would it hurt if I
sprayed the plant to kill the mold? Is it mold?

Thanks for the replies,
Gene


Gene, what is above the plant? Are there other plants up higher?
Anything from other orchids to a shade tree? Black sooty mold is usually
from something dripping down from above, but it could be growing on sap
from within your plant as you suggest.
Before I did anything else, I would take the plant to a sink and get my
hands real soapy (dish soap is fine) and massage every leaf and
pseudobulb until it's all soapy and clean. Rinse all the soap completely
off. This should get rid of the mold, get rid of what the mold is living
on, and get rid of any microscopic critters that may (or may not) be
contributing to the problem.

Steve

Gene: Physan won't hurt it, but I don't think it would be more than a
temporary fix, and you'd probably still have to wipe, afterward. The only
other tip I can offer is that we most often see this problem in an area of
"dead air space." I.e., where we have a fan out of service, or where other
plants are blocking the breeze. If you can increase air movement for this
particular plant, I think you'll see less of the black gunk. Kenni

"Gene Schurg" wrote in message
news:1EQbf.3807$vC6.1406@trnddc05...
Nothing but glass is above this plant. It must be caused by something
being
exuded from the leaves.

Gene


"Steve" wrote in message
...
Gene Schurg wrote:
I've been watching this plant for the entire summer. The black crap
has
been there all summer and there has been no scale or mealies. That was
the
first thing I thought and I've checked it many times.

As Kenni said it's mostly makes the plant look "dirty" but doesn't seem
to
bother the health of the plant.

I'll wipe it off but as the plant grows larger this will be more of a
problem keeping it looking good. What about Physan? Would it hurt if
I
sprayed the plant to kill the mold? Is it mold?

Thanks for the replies,
Gene


Gene, what is above the plant? Are there other plants up higher?
Anything from other orchids to a shade tree? Black sooty mold is usually
from something dripping down from above, but it could be growing on sap
from within your plant as you suggest.
Before I did anything else, I would take the plant to a sink and get my
hands real soapy (dish soap is fine) and massage every leaf and
pseudobulb until it's all soapy and clean. Rinse all the soap completely
off. This should get rid of the mold, get rid of what the mold is living
on, and get rid of any microscopic critters that may (or may not) be
contributing to the problem.

Steve

Ray wrote:

Gene,

I hope I'm wrong here, but sometimes such sooty deposits are a precursor to
a scale infestation (or is it mealies?).

Hi Gene,

Don't know if it is a precursor; however, use Physan on the mealies and
Voltex on the scale to rid it.

.. . . Pam
Everything Orchid Management System
http://home.earthlink.net/~profpam/page3.html

-----------------------

Hi there Pam, Long time no see no hear???
Curious about Voltex? Where do you get it? I have a very bad infestation
of scale.
I am trying the very expensive combo of Enstar II & Mavrik a strict
regimen of
spraying at certain intervals so hope it works.

--
Cheers Wendy

Remove PETERPAN for email reply

profpam wrote:
Ray wrote:

Gene,

I hope I'm wrong here, but sometimes such sooty deposits are a
precursor to a scale infestation (or is it mealies?).

Hi Gene,

Don't know if it is a precursor; however, use Physan on the mealies
and Voltex on the scale to rid it.

. . . Pam
Everything Orchid Management System
http://home.earthlink.net/~profpam/page3.html

-----------------------