I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing tissue
on the bottoms and bases of leaves of all types of phals, which tends to
stop progressing if I hit them with miticides, so I assume that is just mite
damage (which mites hit the phals? I can't see them. They must be a lot
smaller than the spider mites on the catasetums.)

-danny

Danny,

Which miticide do you use? Last spring, I noticed flower and leaf damage on
our Phals, and also fine spider webs. Couldn't see anything, even with a mag
glass, and a "white paper test" was inconclusive. I assumed spider mites. (I
know - assumptions. But what else can one do?)

What I used was 2 Tb. dish soap + 2 Tb. cooking oil/gal water as a drench,
twice. Seemed to work, but I'm seeing some patches again. Kenni mentioned a
heavy duty miticide which kills the up and comers as well as the adults.
Very pricey. Kenni, are you out there?

Diana

"danny" wrote in message
.. .
I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing tissue
on the bottoms and bases of leaves of all types of phals, which tends to
stop progressing if I hit them with miticides, so I assume that is just
mite damage (which mites hit the phals? I can't see them. They must be a
lot smaller than the spider mites on the catasetums.)

-danny

one *guess* as to the pale chlorotic blotches on thin leaved Phals would be
what Christenson says in his book on page 29, the last paragraph about
"leaves":

"The leaves of many species of subgenus Polychilos show mosaic patterning of
several more or less pallid green shades that may be a result of nutritional
deficiencies in cultivation. Species related to P. lueddemanniana, in
particular, typically produce foliage mottled with minute sectors of paler
green coloration. Although falsely attributed to a "possible" virus, the
cause of this mottling is unknown. Specific studies should be undertaken to
ascertain the possibility of calcium or other mineral deficiency in this
species cluster."

When ever I see this on my thin leaved Phals I think it could also be an
internal "systemic" patch of fugal infection. I have even wondered if this
is something that might be attributed to what my botany teacher called MLOs
so when I read Christenson's paragraph I found it to be a of relief sorts, I
thought, "so it may be normal for the species under stress and may be a
nutritional deficiency."

The buzz words "silvery areas with collapsing tissue" indicate a mite
infection to me, especially on Phals. At least that's what I would treat
for first. I like a miticide called "Ovation" It's stains everything the
unmixed chemical touches a pretty pink color so you know when you have
inadvertently smeared it on things like fingers and drinking cups but it is
known to kill all growth stages down to the eggs. P.S., if you ARE
discovering pink stains on things, you should reveiw the section of the
label that talks about appropriate protective gear when handling this
chemical.

The common name for Tenuipalpus pacificus is "Phalaenopsis mite" but there
is a Tenuipalpus species called T. orchidarum I saw mentioned recently
someplace. I think that is suppose to indicate it lives on orchids. The
mites from the genus Tenuipalpus are called 'flat mites". I don't think
they make webs like the ones in the genus that contains 'spider' mites. I
also think they are about 1/2 to 1/4 the size of spider mites, so they are
tiny and flat and live in the very small depressions that they create from
feeding and tend not to move around much. You need a loop (okay, a loupe)
to see them clearly, unless you have a whole lot of them in which case you
probably found the symptoms first, "silvery bumpy areas followed by tissue
collapse. A heavy mite infestation is almost surely accompanied by
secondary injury from opportunistic fungi and bacteria that enter the plant
through the damage caused by the mites feeding on the weakend plant. In my
experiance I have not found that 'shake the leaf over a white sheet of
paper' trick to work well with the very tiny mites, but maybe that's just
me. Its pretty fool proof with spider mites, if you have enough of them.

"danny" wrote in message
.. .
I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing tissue
on the bottoms and bases of leaves of all types of phals, which tends to
stop progressing if I hit them with miticides, so I assume that is just
mite damage (which mites hit the phals? I can't see them. They must be a
lot smaller than the spider mites on the catasetums.)

-danny

I just hit them with a couple shots of Avid but I need to buy some more
(just noticed some damage on the phals upstairs too). I think that's around
$100 for 8 oz. I got a little bit (1/2oz.?) in a group order from another
plant society I was in last year. Some of the miticides run $200-$300 a
bottle. I think I have some Pentac that a friend gave me around here
somewhere. I think the Pentac knocked down the population last year. I
really need to get better about spraying several applications to make sure I
get all of them.

I can see spider mites on plants without a magnifying glass. I don't really
see webs on the catasetums but the bugs look like the spider mites I've seen
on some of our other houseplants. I guess if I did look at them with a
magnifier then maybe I could look up some mite pics on the web and verify
what they are.

If Kenni has a recommendation for current miticides I'd like to hear it.

-danny


"Diana Kulaga" wrote in message
...
Danny,

Which miticide do you use? Last spring, I noticed flower and leaf damage
on our Phals, and also fine spider webs. Couldn't see anything, even with
a mag glass, and a "white paper test" was inconclusive. I assumed spider
mites. (I know - assumptions. But what else can one do?)

What I used was 2 Tb. dish soap + 2 Tb. cooking oil/gal water as a drench,
twice. Seemed to work, but I'm seeing some patches again. Kenni mentioned
a heavy duty miticide which kills the up and comers as well as the adults.
Very pricey. Kenni, are you out there?

Diana

"danny" wrote in message
.. .
I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing tissue
on the bottoms and bases of leaves of all types of phals, which tends to
stop progressing if I hit them with miticides, so I assume that is just
mite damage (which mites hit the phals? I can't see them. They must be a
lot smaller than the spider mites on the catasetums.)

-danny

I *think* Alan Koch's article was in the IPA Journal a few editions ago. He
talked about his feeding regimen in that article. He also talks (perhaps it
was in the Orchid Digest article) about using Iron sulfite (not the form
that is in Ironite)(I think) in dilute concentrations as well as using algae
solution in his water. Says the plant hormones in teh algae solution aids
in root developement...

Anyway, I think the chlorosis is a trace mineral deficinecy.

K Barrett

http://www.aospacificcentral.org/articles/koch.html
"danny" wrote in message
.. .
I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing tissue
on the bottoms and bases of leaves of all types of phals, which tends to
stop progressing if I hit them with miticides, so I assume that is just
mite damage (which mites hit the phals? I can't see them. They must be a
lot smaller than the spider mites on the catasetums.)

-danny

I stopped my infection by watering my plants once a week with Spectracide
Immunox mix. I don't know if I had the same microfungus that everyone spoke
of here (it looked and acted the same) The Spectracide Immunox stopped what
was killing my phals and they've been clean for over a year now. Note;After
I started seeing an improvement I then used the mix once a month. This may
only work with a collection small enough to be hand watered. I had about
100 Phal plants under lights at the time.


http://www.spectracide.com/ProductCa...e/SpectracideI
mmunox/

Grow well and bloom magnificently

dusty

I don't think I tried that one. What is the active ingredient? I assume
it's not the same as Clearys 3336. (I can look this up for myself later,
when I have a few more minutes.)
I don't believe I've ever seen a systemic fungicide (or systemic
anything, for that matter) that was labeled for use on fruit trees. How
do they get away with that?

Steve

Dusty wrote:
I stopped my infection by watering my plants once a week with Spectracide
Immunox mix. I don't know if I had the same microfungus that everyone spoke
of here (it looked and acted the same) The Spectracide Immunox stopped what
was killing my phals and they've been clean for over a year now. Note;After
I started seeing an improvement I then used the mix once a month. This may
only work with a collection small enough to be hand watered. I had about
100 Phal plants under lights at the time.


http://www.spectracide.com/ProductCa...e/SpectracideI
mmunox/

Grow well and bloom magnificently

dusty

I'll ask Kenni what the name is again. I do remember that the cost is around
$240/quart, but it's highly concentrated. So, a group purchase would be the
way to go.

Diana

"danny" wrote in message
. ..
I just hit them with a couple shots of Avid but I need to buy some more
(just noticed some damage on the phals upstairs too). I think that's
around $100 for 8 oz. I got a little bit (1/2oz.?) in a group order from
another plant society I was in last year. Some of the miticides run
$200-$300 a bottle. I think I have some Pentac that a friend gave me
around here somewhere. I think the Pentac knocked down the population last
year. I really need to get better about spraying several applications to
make sure I get all of them.

I can see spider mites on plants without a magnifying glass. I don't
really see webs on the catasetums but the bugs look like the spider mites
I've seen on some of our other houseplants. I guess if I did look at them
with a magnifier then maybe I could look up some mite pics on the web and
verify what they are.

If Kenni has a recommendation for current miticides I'd like to hear it.

-danny


"Diana Kulaga" wrote in message
...
Danny,

Which miticide do you use? Last spring, I noticed flower and leaf damage
on our Phals, and also fine spider webs. Couldn't see anything, even with
a mag glass, and a "white paper test" was inconclusive. I assumed spider
mites. (I know - assumptions. But what else can one do?)

What I used was 2 Tb. dish soap + 2 Tb. cooking oil/gal water as a
drench, twice. Seemed to work, but I'm seeing some patches again. Kenni
mentioned a heavy duty miticide which kills the up and comers as well as
the adults. Very pricey. Kenni, are you out there?

Diana

"danny" wrote in message
.. .
I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing
tissue on the bottoms and bases of leaves of all types of phals, which
tends to stop progressing if I hit them with miticides, so I assume that
is just mite damage (which mites hit the phals? I can't see them. They
must be a lot smaller than the spider mites on the catasetums.)

-danny

Let's expand this to include other orchids. Some (not all!) of our plants
have a mottled color on the leaves, darker/lighter green. Thick leafed Catts
and some Dends are showing this. Flowering is normal. This does not look
like a fungus in any way, nor does it appear to be a virus. The leaves do
not drop, nor do they develop sunken spots. I initially attributed this to
drops in temperature last winter, but I'm seeing it more. (No severe temp
changes down here in many months.)

I haven't changed feeding regimens; we use Peters 20/20/20 w/micronutrients.
I am not seeing this condition on our Oncidium types. The only two Phals
that seem to be affected are a lueddemanniana and a tetraspis, and those
spots really could be left over from the Mite situation.

So, it's possible that what's causing this is a nutritional deficiency? How
would one determine what's missing?

Diana

"al" wrote in message news:Z22Og.3723$xh3.848@trnddc01...
one *guess* as to the pale chlorotic blotches on thin leaved Phals would
be what Christenson says in his book on page 29, the last paragraph about
"leaves":

"The leaves of many species of subgenus Polychilos show mosaic patterning
of several more or less pallid green shades that may be a result of
nutritional deficiencies in cultivation. Species related to P.
lueddemanniana, in particular, typically produce foliage mottled with
minute sectors of paler green coloration. Although falsely attributed to
a "possible" virus, the cause of this mottling is unknown. Specific
studies should be undertaken to ascertain the possibility of calcium or
other mineral deficiency in this species cluster."

When ever I see this on my thin leaved Phals I think it could also be an
internal "systemic" patch of fugal infection. I have even wondered if
this is something that might be attributed to what my botany teacher
called MLOs so when I read Christenson's paragraph I found it to be a of
relief sorts, I thought, "so it may be normal for the species under stress
and may be a nutritional deficiency."

The buzz words "silvery areas with collapsing tissue" indicate a mite
infection to me, especially on Phals. At least that's what I would treat
for first. I like a miticide called "Ovation" It's stains everything the
unmixed chemical touches a pretty pink color so you know when you have
inadvertently smeared it on things like fingers and drinking cups but it
is known to kill all growth stages down to the eggs. P.S., if you ARE
discovering pink stains on things, you should reveiw the section of the
label that talks about appropriate protective gear when handling this
chemical.

The common name for Tenuipalpus pacificus is "Phalaenopsis mite" but there
is a Tenuipalpus species called T. orchidarum I saw mentioned recently
someplace. I think that is suppose to indicate it lives on orchids. The
mites from the genus Tenuipalpus are called 'flat mites". I don't think
they make webs like the ones in the genus that contains 'spider' mites. I
also think they are about 1/2 to 1/4 the size of spider mites, so they are
tiny and flat and live in the very small depressions that they create from
feeding and tend not to move around much. You need a loop (okay, a loupe)
to see them clearly, unless you have a whole lot of them in which case you
probably found the symptoms first, "silvery bumpy areas followed by tissue
collapse. A heavy mite infestation is almost surely accompanied by
secondary injury from opportunistic fungi and bacteria that enter the
plant through the damage caused by the mites feeding on the weakend plant.
In my experiance I have not found that 'shake the leaf over a white sheet
of paper' trick to work well with the very tiny mites, but maybe that's
just me. Its pretty fool proof with spider mites, if you have enough of
them.

"danny" wrote in message
.. .
I get yellow chlorosis on quite a few of my thinner-leaved phals, without
any other symptoms. Anyone know what may cause that? It doesn't seem to
seriously harm the plant. I also get silvery areas with collapsing tissue
on the bottoms and bases of leaves of all types of phals, which tends to
stop progressing if I hit them with miticides, so I assume that is just
mite damage (which mites hit the phals? I can't see them. They must be a
lot smaller than the spider mites on the catasetums.)

-danny

OK, I looked it up this is what it is:
http://www.pesticideinfo.org/Detail_...p?Rec_Id=PC120


Steve wrote:

I don't think I tried that one. What is the active ingredient? I assume
it's not the same as Clearys 3336. (I can look this up for myself later,
when I have a few more minutes.)
I don't believe I've ever seen a systemic fungicide (or systemic
anything, for that matter) that was labeled for use on fruit trees. How
do they get away with that?

Steve

Dusty wrote:

I stopped my infection by watering my plants once a week with
Spectracide Immunox mix. I don't know if I had the same microfungus
that everyone spoke of here (it looked and acted the same) The
Spectracide Immunox stopped what was killing my phals and they've been
clean for over a year now. Note;After I started seeing an improvement
I then used the mix once a month. This may only work with a collection
small enough to be hand watered. I had about 100 Phal plants under
lights at the time.


http://www.spectracide.com/ProductCa...e/SpectracideI

mmunox/

Grow well and bloom magnificently

dusty

With respect to the "microfungus," I've often wondered if it's not
something like impatiens necrotic spot virus (INSV), which used to be
known as tomato spotted wilt virus (impatiens strain). It could also be
latent INSV that manifests only in conjunction with a fungus infection,
which would explain how it apparently goes through a collection so
quickly: a vector spreads the INSV, which stays latent for a period of
time, appearing only when weakened by a fungus that spreads more rapidly.

Agdia makes an ImmunoStrip test kit; $50 for 5, or $97.50 for 25
tests, and it's simple enough anyone can do it in their own greenhouse. I
don't know as anyone has ever run a test for INSV in this manner.

Really, almost any state department of agriculture should have a
competent plant pathologist that can do some basic tests. In New Mexico,
we were fortunate enough to have a PhD in plant path that worked for
Stewart's when she was either an undergrad or a grad student. Here in
Arizona, I've had an "anthracnose-like" fungus teased out of a sample I
sent them once. These aren't exactly hotbeds of orchid agriculture, so one
hopes that Florida and California would have more experience with this
sort of thing.

The address in the header isn't valid. Send no email there.

Cheers,

-AJHicks
Chandler, AZ

I got a chance to talk to Dr. Griesbach as he was leaving NCOS judging last
week. He said microfungus is a real thing and a couple of species are know
to inflict orchids. I did not ask for species names, I knew I would never
remember. Sorry Al, I forgot to ask what the difference was between a
microfungus and a fungus.

Dr. Griesbach said claims of microfungus infections are not as common as
they were 5 - 10 years ago for a couple of reasons. First, when microfungus
was first being discussed, a lot of plants with false spider mite damage
were being labeled as microfungus. Second, it seems that virus tests from
this time period had problems and a lot of false negative results were
reported. Based on these false negative reports, viruses plants were being
reported to have microfungus. Dr. Griesbach said that today's virus testing
antigens are much better and have greatly reduced the number of false
negative results.

Dr Griesbach said most microfungus problems resulted as a secondary
infection. I asked if curing microfungus required the approach recommended
by Gordon or if newer fungicides such as Clearies 3336 would work. He said
fungicides such as 3336 should work but you had to follow the label in terms
of both strength and minimal time before respraying. We both agreed it was
a hard, but not impossible, thing to get completely cured.

Pat


"Pat Brennan" wrote in message
...
BobGordon "Culture of the Phalaenopsis Orchid"

. . ."sometimes a condition prevails that is caused by a systemic
infection of microfungi. As there are literally hundreds of these, the
symptoms vary from plant to plant.

Some of the more common are a spotty, ill-defined chlorosis; a streaky
chlorosis beginning at the edge of the leaf where it looks as if the leaf
edge had been burned with a match or candle; a red-brown coloration
appearing at the apical third or half of the lower leaves followed by a
dehydrated and senescent (old) appearance and also mesophyll tissue
collapse where deep pitting becomes apparent on the surface of the leaves.
This latter condition can also be caused by cold water and by virus
infections. However, in the latter instance, the pitting is usually
dark-brown to black in appearance rather than the white to light fawn
caused by fungi.
.
.
.
We still don't have a handle on what is causing the disease yet or even
what it is, but efforts are underway at two state universities. It may be
a fungal disease and virus in combination, confusing the diagnosis, but
there is little question that the disease weakens the plant and leaves it
susceptible to more common ailments such as Pseudomonas cattleyae.

Bayleton may be the agent that is correcting the problem, however, There
have been reports that the Bayleton alone will correct the problem. There
is one report that Subdue alone corrected the problem.

Symptons of the problem are similar to those of a photo of a specimen of
fungal leafspot caused by Guignardia sp. shown on page 84 of the 1986
edition of the AOS's Handbook on Orchid Pests and Diseases. However, to
date, that disease only has been reported in vandas and ascocendas. If
the disease is fungal in nature, it does not respond to the standard
culture tests. At least three efforts have resulted in no germination."


BobGordon '"Phal Cultu A Worldwide Survey."

"Microfungus Phal growers may be facing a major newly-discovered
(observed?) problem. This is the yellow pitting, necrotic spotting of the
leaves, preliminarily diagnosed by John Miller and Rob Griesbach as a
micro-fungus.
. . . Growers who have followed various recommendations on ridding their
collection of this problem have largely been unsuccessful. Nothing
sprayed, drenched or applied in any manner seems to make any inroads on
the disease. . . .--T. Happer"

"Systemic Microfungus To my knowledge, Ernie Campuzano of Butterfly
Orchids in Newburry Park Ca, was the first grower to experience the
microfungus problem on a large scale. . . . Ernie had all the symptoms Tom
Harper talks about above and related the problem to John Miller, who in
turn related it to Don Baker of Stoufer Labs. Don identified the problem
as a systemic microfungus and developed the following therapy. . .
.-editor"

I would say symptom are, in the order of appearance, yellow chlorosis,
more defined yellow spotting, pitting, large areas of grayish brown tissue
collapse.

Pat

Yes, I had the exact same experience with about a dozen Phals & they looked
just like Steve's pictures.
I tried all kinds of fungicides especially made for orchids but nada?
Ended up throwing them all away! I remember writing in here was when I first
joined up, saying that it started like someone splashed bleach on the leaves, then
they pitted, turned dry & also black edges etc. etc.

--
Cheers Wendy

No Spam Email Address Invalid
"Steve" wrote in message
...
al wrote:

Here is the link to Steve's pictures and it works. (All praise the internet!) It
is hard to read the archived post but it looked like some people, including Pat and
Aaron (two people who from my point of view tend to know what they are talking
about)thought some of the pictures looked like what they called microfungus. (To
me one looks like mite damage, but not all of them. Taken together, the group of
pictures looks like a lot of different problems to me.)

Okay group, from top to bottom, refresh my memory....which pictures look like
microfungus?
http://www.geocities.com/tlswilso/Phal_problems.html
..............
........

Yeah, that's the page I made. I was going to show it if nobody else did.

I haven't done anything with it in a long time. The disease seems to be as incurable
as a virus but it spreads easier than most fungus diseases. (No physical contact
needed.)
At this point, I have one of the diseased plants left. It is my oldest orchid; the
first orchid I ever owned from back in the mid 70s. It has one small leaf left. It
looks normal but the disease will soon show itself in that last leaf and that will
be it. It's in a window away from my other orchids.
After that last one dies off, I believe I will be free of the disease. I hope it
isn't hidden in my other (non Phal) orchids waiting to reinfect any future Phals I
may buy. The original post mentioned Paphs and Phrags as being susceptible. I do
have a few of each showing some symptoms but I can't look at them and see the same
disease. Maybe I should look closer with that thought in mind.
I've been thinking lately that after the last Phal dies, I should go back and make
one last update to the Phal Disease page. Sounds like a project for some rainy fall
day.

Steve

Pat Brennan wrote:

I got a chance to talk to Dr. Griesbach...............
........ I asked if curing microfungus required the approach recommended
by Gordon or if newer fungicides such as Clearies 3336 would work. He said
fungicides such as 3336 should work but you had to follow the label in terms
of both strength and minimal time before respraying..................

When I was still trying to fight the problem I had with my Phals, I
sprayed with Clearys 3336 a few times and noticed not one bit of
difference. The disease just continued to progress as before.

Steve

In article ,
Steve wrote:

I don't think I tried that one. What is the active ingredient? I assume
it's not the same as Clearys 3336. (I can look this up for myself later,
when I have a few more minutes.)
I don't believe I've ever seen a systemic fungicide (or systemic
anything, for that matter) that was labeled for use on fruit trees. How
do they get away with that?

Steve


Why would you want a systemic anything for a fruit tree, unless you were
not planning on anyone eating the fruit?

Only fungicide that I have ever used on my fruit trees is copper.