# Spotting on leafs



## andre (Sep 28, 2014)

Wow. I have not put up a post for a while...
Question to you Paph. growers out there. What do you think the spotting is from? Somehow over the summer many of my mottled leaved species... 
I have sprayed them with Captan recently, the number of spots have increased, but they have more defined margins on both top and bottom surfaces. I also have some RD20 around, but have not used it yet.






I grow under a 1000 watt metal halide light. The paphs are 6 feet away, intermediate temperatures, 50% humidity, and a oscillating fan covers the whole room. 



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## troy (Sep 28, 2014)

I have some orange stuff on mine I was looking into using bleach in a dilute or colloidol silver


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## andre (Sep 28, 2014)

I'm sure the problem can be cured... I'm sure the plants are ok... Bacterial, or fungal, pests?


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## Justin (Sep 28, 2014)

Looks like minor.fungal infection. Your culture sounds genarally good...maybe more airflow? Also avoid water splashing across the plants maybe.


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## andre (Sep 28, 2014)

So the captan should do the trick then. 


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## eggshells (Sep 28, 2014)

It looks like Colletotrichium. Its contagious and spreads to other plants as well via water. Treat with systemic fungicide and isolate the plants. Its curable but you have to be patient. You have to wait for new leaves until you will know its if you were able to neutralize it. Treat with Azoxystrobin. Not sure if mancozeb and Thiomyl will be effective. Worth a try perhaps.


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## Erythrone (Sep 28, 2014)

So you think it is anthracnose, Eggshell?


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## eggshells (Sep 28, 2014)

Erythrone said:


> So you think it is anthracnose, Eggshell?



Some sort of colletotrichum I think. Could be anthracnose. It starts as yellow then turns to brown in the middle? I could be wrong as well. But for sure its a bacterial infection and can be cured.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582005000400021


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## Erythrone (Sep 28, 2014)

Colletotrichum is a fungus oke:


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## eggshells (Sep 28, 2014)

Erythrone said:


> Colletotrichum is a fungus oke:



Thanks for the correction. 

The systemic fungicide I stated above should work. It was recommended by Xavier. 

http://www.arpnjournals.com/jabs/research_papers/rp_2007/jabs_0507_48.pdf


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## troy (Sep 28, 2014)

Do you think diluted bleach will work, or colloidol silver?


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## lepetitmartien (Sep 28, 2014)

Yup maybe fungus, there's others candidates in the fungus world but the treatment will be over the same lines. As it's anyway inside the leaf, something systemic is mandatory.

And please, check for mites, Brevipalpus especially (smaller, no web)


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## abax (Sep 28, 2014)

Cleary's 3336 and yes, I know I keep harping on Cleary's. It works.


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## troy (Sep 29, 2014)

What do the mites look like? Color, size etc..


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## lepetitmartien (Sep 29, 2014)

Best is to check with a bit a surgical cotton, with alcohol 70° (Cooper for example). Pass it under all leaves (start with the healthy ones, or best, one cotton per leaf) if you have some yellowish-brown-reddish stains, bingo.

Mites can be of different colors, we call them red spiders in French though only one stage of one species is red… The common species like Tetranychus are so small you have to use a magnifier at least but if you have very very good eyes, you can see them if you know where to look at. Those common ones are making small webs on the plants, close, to help them moving between plant parts. The false spidermite on the other end is even smaller (one fourth of Tetranichus), and waves no web but even more than the others brings nasty things with it, like a mandatory fungus, and OFV (orchid fleck virus) for the lucky ones.

For this plant other things can match like Acidovorax bacteria (stop splashing these leaves!), Guignardia/Phyllosticta fungus at its round stage, and certainly others.

Bleach won't be enough though can help for bacteria. But I'd avoid splashing sane leaves with water coming from the bad ones. Bordeaux mixture can help a lot.

If it's a fungus (I'm more in this direction btw), a systemic is necessary. And I'll cut those affected leaves, the necrotic parts are sporea flowerings, it'll spread.

The closest thing I know looking like it are damages I've seen on Vanillas either mine, at the MNHN (french natural history national museum) in their orchid collection and the Serres d'Auteuil (Paris city botanic garden). I guess it's a fungus, but I don't know more, and the gardeners at the museum are at loss too. I occurs only in summer, I'm not around when it happens so can't watch stages. It looks like small craters.


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## Bjorn (Sep 29, 2014)

Seen it in my collection, its Colletotrichium. Seems to get arrested by spraying a combo of mancozeb+thiomyl+copper.
Are those plants "jungle-plants"?


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## andre (Sep 29, 2014)

Very hard to find systemic anything here in Canada. I usually have to cross the border to Washington to get things. Do any Canadians here know of a legal systemic? I do have Bayer 3 in one. 


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## eggshells (Sep 29, 2014)

Well Bjorn mentioned copper so perhaps this copper spray will work? Though I am not sure what is the efficacy of that one as I have not tried one myself.

The systemic ones.. I don't think you can get those here in Canada. Sorry, not much help on that.


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## SlipperFan (Sep 29, 2014)

troy said:


> What do the mites look like? Color, size etc..



There is also the two-spotted spider mite. very tiny. Can't see them without a magnifying glass. They are a pale yellowish-brown with two dark spots on their backs. They love Paphs, Phals and Catasinae.


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## Ozpaph (Sep 30, 2014)

andre said:


> Very hard to find systemic anything here in Canada. I usually have to cross the border to Washington to get things. Do any Canadians here know of a legal systemic? I do have Bayer 3 in one.
> 
> 
> Sent from my iPad using Tapatalk



Ebay works


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## lepetitmartien (Sep 30, 2014)

SlipperFan said:


> There is also the two-spotted spider mite. very tiny. Can't see them without a magnifying glass. They are a pale yellowish-brown with two dark spots on their backs. They love Paphs, Phals and Catasinae.


Call it Brevipalpus for short.


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## eaborne (Sep 30, 2014)

I would definitely increase the airflow along with treating it.


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## Happypaphy7 (Oct 4, 2014)

Those are not from mites, but disease spots.
You want to remove the affected leaves and spray.

One of the paphs I bought at a show from OZ was covered with them.
I only found out when I came home at night.
The plant did not do well in the long run.


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## Trithor (Oct 4, 2014)

It is worth remembering that our plants (and us) live in a contaminated world.they are surrounded by a whole range of fungi and bacteria and normally do not show any effect from them. The spots, rot and other ailments occure when there is a cultural problem, imbalance or a biting insect which breaches the plants normal resistance to illness. So to correct this we need to correct the cultural problem, correct the imbalance or remove the biting insect. Most often the first indication we have of a pest (other than mountains of wooly mealy bug, or textured surfaces of scale) are the results of infection of the insect bites. In this case we need to treat not only the insect pest, but the pathogen which has gained access to the plant tissue. I point this out, because all to often the discussion is centered around treating the one or the other in isolation, while the reality is that both are involved and in need of treatment. At risk of appearing foolish, I believe that a lot of the problems we experience is because we grow lots of a specific type of plant in an artificial environment and then use artificial feeds and add to the problem by using pesticides, fungicides and other treatments and so create an environment that is very out of balance and easily capitalized as a niche environment by a pest or pathogen, much as hospitals are environments in which really nasty bugs can thrive.
First correct the imbalance (improve airflow, reintroduce effective microbes, watch and treat for insect infestations and drink more beer)


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## SlipperFan (Oct 4, 2014)

lepetitmartien said:


> Call it Brevipalpus for short.



OK


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## Erythrone (Oct 4, 2014)

Trithor said:


> It is worth remembering that our plants (and us) live in a contaminated world.they are surrounded by a whole range of fungi and bacteria and normally do not show any effect from them. The spots, rot and other ailments occure when there is a cultural problem, imbalance or a biting insect which breaches the plants normal resistance to illness. So to correct this we need to correct the cultural problem, correct the imbalance or remove the biting insect. Most often the first indication we have of a pest (other than mountains of wooly mealy bug, or textured surfaces of scale) are the results of infection of the insect bites. In this case we need to treat not only the insect pest, but the pathogen which has gained access to the plant tissue. I point this out, because all to often the discussion is centered around treating the one or the other in isolation, while the reality is that both are involved and in need of treatment. At risk of appearing foolish, I believe that a lot of the problems we experience is because we grow lots of a specific type of plant in an artificial environment and then use artificial feeds and add to the problem by using pesticides, fungicides and other treatments and so create an environment that is very out of balance and easily capitalized as a niche environment by a pest or pathogen, much as hospitals are environments in which really nasty bugs can thrive.
> First correct the imbalance (improve airflow, reintroduce effective microbes, watch and treat for insect infestations and drink more beer)



:clap::clap::clap:


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## Bjorn (Oct 6, 2014)

Trithor said:


> It is worth remembering that our plants (and us) live in a contaminated world.they are surrounded by a whole range of fungi and bacteria and normally do not show any effect from them. The spots, rot and other ailments occure when there is a cultural problem, imbalance or a biting insect which breaches the plants normal resistance to illness. So to correct this we need to correct the cultural problem, correct the imbalance or remove the biting insect. Most often the first indication we have of a pest (other than mountains of wooly mealy bug, or textured surfaces of scale) are the results of infection of the insect bites. In this case we need to treat not only the insect pest, but the pathogen which has gained access to the plant tissue. I point this out, because all to often the discussion is centered around treating the one or the other in isolation, while the reality is that both are involved and in need of treatment. At risk of appearing foolish, I believe that a lot of the problems we experience is because we grow lots of a specific type of plant in an artificial environment and then use artificial feeds and add to the problem by using pesticides, fungicides and other treatments and so create an environment that is very out of balance and easily capitalized as a niche environment by a pest or pathogen, much as hospitals are environments in which really nasty bugs can thrive.
> First correct the imbalance (improve airflow, reintroduce effective microbes, watch and treat for insect infestations and drink more beer)



About time to start with a holistic approach to the orchid growing? My experience is that if I have repeated problems with deceases, its either some very hostile pathogen(normally not) or the growing conditions are not optimal.
Sub-optimal growing conditions opens up the plants immune system to attack. A well-grown (not necessarily big and beautiful) plant is not prone to attack. So the counter-action in this case would be to spray, and if the attack repeats itself then look for your growing conditions. Is something missing? some stress? etc. While knocking down the repeated attack with proper action of course.


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## Trithor (Oct 6, 2014)

I agree, every time we treat an ailment, we should at the same time try and identify the cause and the circumstances which led to it. I firmly believe (even if I don't want to admit to it) that incorrect culture is the cause of most of the ailments which we see.


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