|
microfungus
if you go to Google groups at
http://groups.google.com/group/rec.gardens.orchids/ and search the archive of this newsgroup for the term "microfungus" you will find threads in which the term has been mentioned as far back as 1995. I don't think anything conclusive has ever been posted about it and I tend to think of it as a kind of 'internet' lore, because I have not been able to find anything written about it anyplace else. I have even asked a few agriculture extension agents I know... None of my text books on botany or pest management mention it, but they all talk a lot about fungus problems. And most fungus diseases that infect living plant tissue are microscopic so the term is somewhat confusing and misleading to begin with and probably applied a bit loosely when nothing else seems to apply... Whenever this term comes up I wait to see if somebody can post something definative. "van" wrote in message oups.com... I was talking with an orchid grower today who warned me about a problem that orchid growers seem to be having, but don't know much about it or what to do. It is called a microfungus and once it sets in it eventually kills the orchid. It spreads very easily throughout a greenhouse or collection and affects phrags, paphs, phals, and other things. Small brown or orange lesions appear mostly on the undersides of leaves and discoloration eventually spreads killing the leaf or entire new growth or eventually the plant. Healthy established plants may have the microfungus symptoms but still grow and bloom. Apparently not much is known about this and there is no known cure. Phyton 27 may help control it but it never seems to go away. One West Coast commercial greenhouse operation apparently lost an entire greenhouse orchid collection to what was attributed to this mysterious "microfungus." Anyone know more about this "microfungus?" Thanks |
microfungus
The best and only write up on the topic that I know of are in BobGordon's
books "Culture of the Phalaenopsis Orchid" and '"Phal Cultu A Worldwide Survey." The pages on cure are well worn in my books. Two of the three required fungicides are not sold in home consumer sizes. If you do not already have Subdue, that will set you back over 200 bucks. I have bought Triadimefon (Bayleton) as Strike 50% WDG (under $100). If I was a hobby grower and it showed up I would try Daconil (consumer size available around $20) and (and not or!) Cleary 3336 (around $50, but a good chemical to have if you have a greenhouse.) treatments for six improvements. If I saw no improvements after 6 months I would toss the plants. Do not assume the plant is cured until you get clean leaves for a year without chemical treatments. A few years back someone in this group posted very good examples of what I call microfungus. I do not think he ever cured it. Based on what I have read in this group it sounds like it can spread to Oncs and maybe other orchids. Pat "al" wrote in message news:BOkNg.3297$xh3.3254@trnddc01... if you go to Google groups at http://groups.google.com/group/rec.gardens.orchids/ and search the archive of this newsgroup for the term "microfungus" you will find threads in which the term has been mentioned as far back as 1995. I don't think anything conclusive has ever been posted about it and I tend to think of it as a kind of 'internet' lore, because I have not been able to find anything written about it anyplace else. I have even asked a few agriculture extension agents I know... None of my text books on botany or pest management mention it, but they all talk a lot about fungus problems. And most fungus diseases that infect living plant tissue are microscopic so the term is somewhat confusing and misleading to begin with and probably applied a bit loosely when nothing else seems to apply... Whenever this term comes up I wait to see if somebody can post something definative. "van" wrote in message oups.com... I was talking with an orchid grower today who warned me about a problem that orchid growers seem to be having, but don't know much about it or what to do. It is called a microfungus and once it sets in it eventually kills the orchid. It spreads very easily throughout a greenhouse or collection and affects phrags, paphs, phals, and other things. Small brown or orange lesions appear mostly on the undersides of leaves and discoloration eventually spreads killing the leaf or entire new growth or eventually the plant. Healthy established plants may have the microfungus symptoms but still grow and bloom. Apparently not much is known about this and there is no known cure. Phyton 27 may help control it but it never seems to go away. One West Coast commercial greenhouse operation apparently lost an entire greenhouse orchid collection to what was attributed to this mysterious "microfungus." Anyone know more about this "microfungus?" Thanks |
microfungus
Cool.
What do these two books say are the symptoms to look out for? Does Bob Gordon say if the term "microfungus" refers to a specific pathogen or group/subgroup of fungus pathogens? It is such a funky word. I am not saying it does not exist as a pathogen to be dealt with... Steve posted links to pictures and the thread you are referring to is mentioned among the threads that come up in the search I mentioned. I don't know if the pictures can still be accessed. I also scanned the links and read some of the symptoms describe when the term was used and they didn't sound like what Van described, of course this means nothing except I didn't see any common buzzword symptoms in the verbal descriptions. I do remember thinking Steve's pictures looked like a mite infection to me, but that's a memory. I didn't try to access the picture link he posted. I also noticed about 3 or 4 over the counter fungicide names that were mentioned as being a cure or treatment in these links. And what you listed used over a 6 month treatment period would cure just about any fungus nature could throw at an orchid plant. "Pat Brennan" wrote in message ... The best and only write up on the topic that I know of are in BobGordon's books "Culture of the Phalaenopsis Orchid" and '"Phal Cultu A Worldwide Survey." The pages on cure are well worn in my books. Two of the three required fungicides are not sold in home consumer sizes. If you do not already have Subdue, that will set you back over 200 bucks. I have bought Triadimefon (Bayleton) as Strike 50% WDG (under $100). If I was a hobby grower and it showed up I would try Daconil (consumer size available around $20) and (and not or!) Cleary 3336 (around $50, but a good chemical to have if you have a greenhouse.) treatments for six improvements. If I saw no improvements after 6 months I would toss the plants. Do not assume the plant is cured until you get clean leaves for a year without chemical treatments. A few years back someone in this group posted very good examples of what I call microfungus. I do not think he ever cured it. Based on what I have read in this group it sounds like it can spread to Oncs and maybe other orchids. Pat "al" wrote in message news:BOkNg.3297$xh3.3254@trnddc01... if you go to Google groups at http://groups.google.com/group/rec.gardens.orchids/ and search the archive of this newsgroup for the term "microfungus" you will find threads in which the term has been mentioned as far back as 1995. I don't think anything conclusive has ever been posted about it and I tend to think of it as a kind of 'internet' lore, because I have not been able to find anything written about it anyplace else. I have even asked a few agriculture extension agents I know... None of my text books on botany or pest management mention it, but they all talk a lot about fungus problems. And most fungus diseases that infect living plant tissue are microscopic so the term is somewhat confusing and misleading to begin with and probably applied a bit loosely when nothing else seems to apply... Whenever this term comes up I wait to see if somebody can post something definative. "van" wrote in message oups.com... I was talking with an orchid grower today who warned me about a problem that orchid growers seem to be having, but don't know much about it or what to do. It is called a microfungus and once it sets in it eventually kills the orchid. It spreads very easily throughout a greenhouse or collection and affects phrags, paphs, phals, and other things. Small brown or orange lesions appear mostly on the undersides of leaves and discoloration eventually spreads killing the leaf or entire new growth or eventually the plant. Healthy established plants may have the microfungus symptoms but still grow and bloom. Apparently not much is known about this and there is no known cure. Phyton 27 may help control it but it never seems to go away. One West Coast commercial greenhouse operation apparently lost an entire greenhouse orchid collection to what was attributed to this mysterious "microfungus." Anyone know more about this "microfungus?" Thanks |
microfungus
It was indeed Steve, and I think he lost some plants that he had owned for
many years. I don't know if he ever found a cure. I had never seen anything like what he posted. Diana "al" wrote in message news:HanNg.10072$OI1.7228@trnddc05... Cool. What do these two books say are the symptoms to look out for? Does Bob Gordon say if the term "microfungus" refers to a specific pathogen or group/subgroup of fungus pathogens? It is such a funky word. I am not saying it does not exist as a pathogen to be dealt with... Steve posted links to pictures and the thread you are referring to is mentioned among the threads that come up in the search I mentioned. I don't know if the pictures can still be accessed. I also scanned the links and read some of the symptoms describe when the term was used and they didn't sound like what Van described, of course this means nothing except I didn't see any common buzzword symptoms in the verbal descriptions. I do remember thinking Steve's pictures looked like a mite infection to me, but that's a memory. I didn't try to access the picture link he posted. I also noticed about 3 or 4 over the counter fungicide names that were mentioned as being a cure or treatment in these links. And what you listed used over a 6 month treatment period would cure just about any fungus nature could throw at an orchid plant. "Pat Brennan" wrote in message ... The best and only write up on the topic that I know of are in BobGordon's books "Culture of the Phalaenopsis Orchid" and '"Phal Cultu A Worldwide Survey." The pages on cure are well worn in my books. Two of the three required fungicides are not sold in home consumer sizes. If you do not already have Subdue, that will set you back over 200 bucks. I have bought Triadimefon (Bayleton) as Strike 50% WDG (under $100). If I was a hobby grower and it showed up I would try Daconil (consumer size available around $20) and (and not or!) Cleary 3336 (around $50, but a good chemical to have if you have a greenhouse.) treatments for six improvements. If I saw no improvements after 6 months I would toss the plants. Do not assume the plant is cured until you get clean leaves for a year without chemical treatments. A few years back someone in this group posted very good examples of what I call microfungus. I do not think he ever cured it. Based on what I have read in this group it sounds like it can spread to Oncs and maybe other orchids. Pat "al" wrote in message news:BOkNg.3297$xh3.3254@trnddc01... if you go to Google groups at http://groups.google.com/group/rec.gardens.orchids/ and search the archive of this newsgroup for the term "microfungus" you will find threads in which the term has been mentioned as far back as 1995. I don't think anything conclusive has ever been posted about it and I tend to think of it as a kind of 'internet' lore, because I have not been able to find anything written about it anyplace else. I have even asked a few agriculture extension agents I know... None of my text books on botany or pest management mention it, but they all talk a lot about fungus problems. And most fungus diseases that infect living plant tissue are microscopic so the term is somewhat confusing and misleading to begin with and probably applied a bit loosely when nothing else seems to apply... Whenever this term comes up I wait to see if somebody can post something definative. "van" wrote in message oups.com... I was talking with an orchid grower today who warned me about a problem that orchid growers seem to be having, but don't know much about it or what to do. It is called a microfungus and once it sets in it eventually kills the orchid. It spreads very easily throughout a greenhouse or collection and affects phrags, paphs, phals, and other things. Small brown or orange lesions appear mostly on the undersides of leaves and discoloration eventually spreads killing the leaf or entire new growth or eventually the plant. Healthy established plants may have the microfungus symptoms but still grow and bloom. Apparently not much is known about this and there is no known cure. Phyton 27 may help control it but it never seems to go away. One West Coast commercial greenhouse operation apparently lost an entire greenhouse orchid collection to what was attributed to this mysterious "microfungus." Anyone know more about this "microfungus?" Thanks |
microfungus
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 "Diana Kulaga" wrote in message ... It was indeed Steve, and I think he lost some plants that he had owned for many years. I don't know if he ever found a cure. I had never seen anything like what he posted. Diana "al" wrote in message news:HanNg.10072$OI1.7228@trnddc05... Cool. What do these two books say are the symptoms to look out for? Does Bob Gordon say if the term "microfungus" refers to a specific pathogen or group/subgroup of fungus pathogens? It is such a funky word. I am not saying it does not exist as a pathogen to be dealt with... Steve posted links to pictures and the thread you are referring to is mentioned among the threads that come up in the search I mentioned. I don't know if the pictures can still be accessed. I also scanned the links and read some of the symptoms describe when the term was used and they didn't sound like what Van described, of course this means nothing except I didn't see any common buzzword symptoms in the verbal descriptions. I do remember thinking Steve's pictures looked like a mite infection to me, but that's a memory. I didn't try to access the picture link he posted. I also noticed about 3 or 4 over the counter fungicide names that were mentioned as being a cure or treatment in these links. And what you listed used over a 6 month treatment period would cure just about any fungus nature could throw at an orchid plant. "Pat Brennan" wrote in message ... The best and only write up on the topic that I know of are in BobGordon's books "Culture of the Phalaenopsis Orchid" and '"Phal Cultu A Worldwide Survey." The pages on cure are well worn in my books. Two of the three required fungicides are not sold in home consumer sizes. If you do not already have Subdue, that will set you back over 200 bucks. I have bought Triadimefon (Bayleton) as Strike 50% WDG (under $100). If I was a hobby grower and it showed up I would try Daconil (consumer size available around $20) and (and not or!) Cleary 3336 (around $50, but a good chemical to have if you have a greenhouse.) treatments for six improvements. If I saw no improvements after 6 months I would toss the plants. Do not assume the plant is cured until you get clean leaves for a year without chemical treatments. A few years back someone in this group posted very good examples of what I call microfungus. I do not think he ever cured it. Based on what I have read in this group it sounds like it can spread to Oncs and maybe other orchids. Pat "al" wrote in message news:BOkNg.3297$xh3.3254@trnddc01... if you go to Google groups at http://groups.google.com/group/rec.gardens.orchids/ and search the archive of this newsgroup for the term "microfungus" you will find threads in which the term has been mentioned as far back as 1995. I don't think anything conclusive has ever been posted about it and I tend to think of it as a kind of 'internet' lore, because I have not been able to find anything written about it anyplace else. I have even asked a few agriculture extension agents I know... None of my text books on botany or pest management mention it, but they all talk a lot about fungus problems. And most fungus diseases that infect living plant tissue are microscopic so the term is somewhat confusing and misleading to begin with and probably applied a bit loosely when nothing else seems to apply... Whenever this term comes up I wait to see if somebody can post something definative. "van" wrote in message oups.com... I was talking with an orchid grower today who warned me about a problem that orchid growers seem to be having, but don't know much about it or what to do. It is called a microfungus and once it sets in it eventually kills the orchid. It spreads very easily throughout a greenhouse or collection and affects phrags, paphs, phals, and other things. Small brown or orange lesions appear mostly on the undersides of leaves and discoloration eventually spreads killing the leaf or entire new growth or eventually the plant. Healthy established plants may have the microfungus symptoms but still grow and bloom. Apparently not much is known about this and there is no known cure. Phyton 27 may help control it but it never seems to go away. One West Coast commercial greenhouse operation apparently lost an entire greenhouse orchid collection to what was attributed to this mysterious "microfungus." Anyone know more about this "microfungus?" Thanks |
microfungus
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 |
microfungus
Wow. That was more information than one normally encounters crammed into a
single post. They sound like good books to have. "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 |
microfungus
On Mon, 11 Sep 2006 21:46:09 GMT in BOkNg.3297$xh3.3254@trnddc01 al wrote:
Whenever this term comes up I wait to see if somebody can post something definative. My gut feeling is that this started with a botany/biology type said "It looks like a Myco..., fungus" and didn't pause long enough. And the end result was not that different from the garbled re-introductions if I walk up to someone and say "Hi, I'm Pakrat" Then again http://en.wikipedia.org/wiki/Microfungus and http://www.devonian.ualberta.ca/uamh/ make me suspect that microfungus is just a confusing name for the most common fungi... Anyhoo, I'd rate 'microfungus' about as helpful as saying someone is a placental mammal. -- Chris Dukes elfick willg: you can't use dell to beat people, it wouldn't stand up to the strain... much like attacking a tank with a wiffle bat |
microfungus
Pat Brennan wrote:
........................... 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, that's about how it progressed on all of my Phals. Steve |
microfungus
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 |
microfungus
Steve,
I know they are plants and not people. But your loss is incredibly sad. I hope the troubles are over for good. Diana |
microfungus
What bothered me about what Bob Gordon wrote was that they still had not
identified the pathogen and suspected it might be a viral/fungus combination. Without the pathogen, how can it be identified as belong to a specific phylum? I found two terms in the library that lead to much more information about microscopic organisms that live inside plant cells and tissue and which may cause vascular plant diseases. Anyway, I heard about MLOs in botany 101 and since I went no furthur I know nothing more than that, as the instructor mentioned one day during this whorl wind introduction to botany, is that they are "ill defined organisms" that seem to be behind many plant diseases. For instance, the pathogen that causes Dutch Elm Disease is among the pathogens called MLOs. They are not all fungi. MLO (microplasma-like organism) seem to be heavily studied and there is lots of specific plants with named disease syndromes where MLOs have been isolated and determined to be the pathogen causing the symptoms. If you add the word orchid to a search of microplasma-like organism it turns up nothing. The terms mycoplasma-like organism and mycoplasmic organism were very helpful. Myco NOT Micro. Myco refers to fungi. (So "mycofungus" would be wrong and annoying in a manner similar to using the terms fungi and fungus interchangeably: you'd have to have a clue in order to even notice.) Mycoplasma has it own wikopedia-like entry. http://microbewiki.kenyon.edu/index.php/Mycoplasma with general information that people worried about "microfungus" might want to read. When you connect this one of the '"myco" terms with "orchid" in a search you DO get a number of interesting hits. The term still refers to a group of parasitic fungi or fungi-like organisms living in the cells and that vascular tissue of plants AND animals, and does not refer to a specific pathogen, so this may be why symptoms vary so wildly. Mycoplasma-"like" also makes me think that whatever they are talking about are not true fungi and why fungicides, even strong systemic ones, sometimes fail to help. I think if the pathogen of this mysterious disease "microfungus" is ever isolated it my be more properly named/grouped with microplasma, mycoplasma or mycoplasma-like organisms "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 |
microfungus
What bothered me was nobody wanted to look for a pathogen. Fears that the
Ag Dept would poo-poo the condition, the tests would be too costly or no one would really take the time to elucidate a 'true' pathogen (like 'You got a virus. Take 2 aspirin and call me in the AM"). K Barrett "al" wrote in message news:2tWNg.1992$FS.1358@trnddc04... What bothered me about what Bob Gordon wrote was that they still had not identified the pathogen and suspected it might be a viral/fungus combination. Without the pathogen, how can it be identified as belong to a specific phylum? I found two terms in the library that lead to much more information about microscopic organisms that live inside plant cells and tissue and which may cause vascular plant diseases. Anyway, I heard about MLOs in botany 101 and since I went no furthur I know nothing more than that, as the instructor mentioned one day during this whorl wind introduction to botany, is that they are "ill defined organisms" that seem to be behind many plant diseases. For instance, the pathogen that causes Dutch Elm Disease is among the pathogens called MLOs. They are not all fungi. MLO (microplasma-like organism) seem to be heavily studied and there is lots of specific plants with named disease syndromes where MLOs have been isolated and determined to be the pathogen causing the symptoms. If you add the word orchid to a search of microplasma-like organism it turns up nothing. The terms mycoplasma-like organism and mycoplasmic organism were very helpful. Myco NOT Micro. Myco refers to fungi. (So "mycofungus" would be wrong and annoying in a manner similar to using the terms fungi and fungus interchangeably: you'd have to have a clue in order to even notice.) Mycoplasma has it own wikopedia-like entry. http://microbewiki.kenyon.edu/index.php/Mycoplasma with general information that people worried about "microfungus" might want to read. When you connect this one of the '"myco" terms with "orchid" in a search you DO get a number of interesting hits. The term still refers to a group of parasitic fungi or fungi-like organisms living in the cells and that vascular tissue of plants AND animals, and does not refer to a specific pathogen, so this may be why symptoms vary so wildly. Mycoplasma-"like" also makes me think that whatever they are talking about are not true fungi and why fungicides, even strong systemic ones, sometimes fail to help. I think if the pathogen of this mysterious disease "microfungus" is ever isolated it my be more properly named/grouped with microplasma, mycoplasma or mycoplasma-like organisms "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 |
microfungus
Hello, me again. I just got an email from someone with too much education
(SMILE): The acyronym "MLO" refers to both "microplasma-like organism" AND "mycoplasma-like organism", with the term "mycoplasma organism" being sufficient and considered to be correct and up to date. Moreover, while the root "myco" or "myc" means fungi in it's purist form, in this usage it does not refer *only* to fungi, but forms of bacteria, Mollicutes (a subgroup of bacteria) and perhaps other intracellular and extracellular organisms. ....and, yes, whatever it is, I too noticed the following line from the Bob Gordon quote and though it was an important part of the pest manegment problem: "It may be a fungal disease and virus in combination, confusing the diagnosis, (and here's the important part) ***but there is little question that the disease weakens the plant and leaves it susceptible to more common ailments***" "al" wrote in message news:2tWNg.1992$FS.1358@trnddc04... ...a bunch of stuff |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus
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 |
microfungus update
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 |
microfungus
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 |
microfungus update
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 |
microfungus
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. |
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