# infection



## Stone (Feb 25, 2013)

I have a fungal infection developing on 2 or 3 paphs. It always attacks the lower leaf where the leaves meet. It starts as a yellow discolouration and gradually turns brown. It distorts the leaf around the area of infection. Spraying with Chorothalonil seems to stop it (slowly). It seems to like warm humid conditions. What the hell is it?


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## wjs2nd (Feb 25, 2013)

Any pictures? Could it be rot?


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## Stone (Feb 25, 2013)

Pictures..













This the same thing about 12 months old




About 3 months old


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## Justin (Feb 25, 2013)

I used to get very similar rot, with the orange soft spots that would start in the new leaves. 

For me, the answer was to increase Ca and Mg in feeding. For immediate treatment, Phyton 27 is effective at stopping the rot from spreading throughout the plant.


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## wjs2nd (Feb 25, 2013)

Hmmmm, I'm not sure. Sorry I can't be more help.

How is your air circulation? Maybe a little more air movement would help. Try anything like H2O (hydrogen peroxide)?


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## Stone (Feb 25, 2013)

Justin. The spots are not soft, just yellow colour on the leaf. They get plenty of Ca/Mg.
Billy. Air has been good lately with the evap cooler on all day and a fan all night. But yes I think even more would be good, but the bills!!!!!!


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## gonewild (Feb 25, 2013)

Can you take closeup photo of the fresh damage?

It somewhat looks like it could be damage from tiny micro slugs or snails. The first picture looks a little like the trail left as the slug eats in a wandering pattern. But that is a guess from looking at the small image with not such good eyesight.


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## consettbay2003 (Feb 26, 2013)

I had similar damage and after checking the areas out with a magnifying loop discovered I had thrips. I think the thrips caused damage to the leaves that allowed a secondary fungus infection to set in. A systemic fungicide/pesticide cleared up the problem.


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## limuhead (Feb 26, 2013)

I have seen this on some of my friends intergeneric oncidiums. According to him, and he is a commercial grower with thousands of oncidinae and paphs, it happens sometimes when the fert level is too high and it is too damp and or not enough light. It made me sick to my stomach, but we ended up throwing away thousands of intergenerics and a bunch of paphs as well. I would isolate the plants that affected if possible...


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## abax (Feb 26, 2013)

Can you buy Cleary's 3336 systemic fungicide in Australia? What about
Orthene 97% granular systemic insecticide? I found that one or the other
takes care of just about any plant problems. I think OFE International
carries both.


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## Secundino (Feb 26, 2013)

As the first markings outline the leaf growing in the older leaf - a sort of open 'v' - I would say samething sits in the crown with the water und hurts the leaf tissue when it dryes up; that would explain the color and that it is no soft rot. 
Perhaps it's not necessary to increase the ventilation but to rise the affected plant about the level of the others - just by a topdown pot beneath. I too believe it's a secundary infection.
Could it be that while potting the affected plants, some dirt got into the crown? It resembles the same color than the lava - some kind of caustic dust (high iron-minerals?)? I always wash the lava a lot to get rid of this dust.
Just thinking aloud...
Luck!


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## wjs2nd (Feb 26, 2013)

Another thing, thinking out loud, I have found brown listerine very effective for killing/curing many things. Plus, it does hurt humans or poison the area.


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## dodidoki (Feb 27, 2013)

Are you sure that it is infection? There are few of my plants with orange spots- similar to your first picture-, I got these plants "with these spots", but these spots do nothing at all. Dry spots and no spreading at all....


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## labskaus (Feb 27, 2013)

This looks pretty similar to what I attribute to false spider mites in my collection.
Look here for more info:
http://www.hark-orchideen.de/Pflanzenschutz/Weichhautmilben/bilder.php?lang=en&navID=99


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## Stone (Feb 27, 2013)

dodidoki said:


> > Are you sure that it is infection?
> 
> 
> 
> Yes positive


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## Stone (Feb 27, 2013)

labskaus said:


> > This looks pretty similar to what I attribute to false spider mites in my collection.
> 
> 
> This definately a primary fungal infection. I have been spraying regularly for mites and mealybug. I have looked very closely for any pests and I cannot see any. Apart from one plant last year, the problem has affected about 4 plants now all in the space of about 2 weeks during very hot and humid weather/conditions. Maybe I helped to spread the spores by dipping the plants in the same bucket of water? As I said, I believe I can stop it with chlorothalonil and I also used micro-fine wettable sulphur on all the plants yesterday just to make sure but I would love to know the correct identity of this disease so I can research it. You must know your enemies well! The internet doesn't help very much.
> ...


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## cnycharles (Feb 27, 2013)

thrips are very resistant to many chemicals, if they are the problem. if you do have them, I would use the sugar-based novel insecticide that Ray B sells as it eats through them instead of being a poison




Stone said:


> labskaus said:
> 
> 
> > This definately a primary fungal infection. ... Maybe I helped to spread the spores by dipping the plants in the same bucket of water? As I said, I believe I can stop it with chlorothalonil and I also used micro-fine wettable sulphur on all the plants yesterday just to make sure but I would love to know the correct identity of this disease so I can research it. You must know your enemies well! The internet doesn't help very much.
> ...


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## Secundino (Feb 28, 2013)

Maybe I helped to spread the spores by dipping the plants in the same bucket of water?

Indeed. And not only if it is fungal infection. Whatsoever is the origin, you will spread it with this method. But I believe you knew this? If not: isolate the affected plants from the rest; look closely on the neighboring plants for any infection. Never work first with the affected plants and then with the healthy, try to find a 'quarantaine routine'. 
I'm still not convinced that it is a fungal infection primary. 
Wish you luck.


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## e-spice (Feb 28, 2013)

I would try dusting with cinnamon. Very inexpensive, nontoxic, and surprisingly effective.


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## Stone (Feb 28, 2013)

Secundino said:


> .
> 
> 
> > Never work first with the affected plants and then with the healthy, try to find a 'quarantaine routine'.
> ...


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## Erythrone (Mar 2, 2013)

consettbay2003 said:


> I had similar damage and after checking the areas out with a magnifying loop discovered I had thrips. .



Same for me.


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## Stone (Mar 4, 2013)

Erythrone said:


> Same for me.



Tell me more about these thrips..What am I looking for?


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## consettbay2003 (Mar 4, 2013)

I was much too complacent in that I am growing in an orchid room and thought I had control over most pest and diseases. Over a period of time I noticed an increase in leaf lesions that I originally attributed to a fungus problem. I sprayed with systemic fungicides but did not get the desired results. After close examination I diagnosed a thrip problem and when I instigated a systemic insecticide/fungicide regime my plants are spotless.


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## SlipperFan (Mar 4, 2013)

consettbay2003 said:


> I was much too complacent in that I am growing in an orchid room and thought I had control over most pest and diseases. Over a period of time I noticed an increase in leaf lesions that I originally attributed to a fungus problem. I sprayed with systemic fungicides but did not get the desired results. After close examination I diagnosed a thrip problem and when I instigated a systemic insecticide/fungicide regime my plants are spotless.


If I may ask, what products did you use?


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## cnycharles (Mar 4, 2013)

thrip are tiny orange insects that many can't see unaided; western flower thrip have either a black head or tail spot. they love to hide in flowers but often will chew on the underside of leaves if there aren't any flowers present. if you tip a flower over a piece of white paper and tap down on the flower, the thrip will fall out and then fly away. if you 'puff' into a flower lightly, often you will see them move up out and then fly away. you can catch them with yellow sticky cards; better with blue ones

I have never had thrip in my apartments, and this was when we had tons of them at the old jobsite! after interviewing for a job at a greenhouse nearby, I soon discovered that some thrip had followed me home either in my cloths or hair and a few were going after my pterostylis flowers (it's snow/winter outside!)


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## wjs2nd (Mar 5, 2013)

I had thrips, at least I believe they were, and killed them with brown listerine.


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## consettbay2003 (Mar 5, 2013)

brown listerine might work but I found it almost impossible to get the pesky thrisps to gargle.


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## SlipperFan (Mar 5, 2013)

consettbay2003 said:


> brown listerine might work but I found it almost impossible to get the pesky thrisps to gargle.



:rollhappy:


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## lepetitmartien (Mar 5, 2013)

No insect can survive an alcohol/soap dispersion (2-3 teaspoons of 70° alcool, one tsp soap, for one liter of water) and there's no resistance, provided it's touched by the mix. If there's thrips involved, a regular spray at least weekly for several weeks may kill the reproduction cycle.

Note that thrips eggs can hatch in 36 hours if it's hot enough, or take weeks if cold. So act accordingly to break the cycle.

Such spray can be done every 2-3 days if needed. But I'd be careful not to let the water between leaves for too long, especially as it should be repeated.

A cinnamon decoction can do but once in a while, as the cinnamon effect on roots is to be prevented.

I'm not sure a chemical path is interesting as they tend to be resistant to a lot of products already, save to fight fungus here, as something looking like Cercospora seems to spread.

My two cents, and reminder: I'm not a slippers grower (yet) So sorry if something I write is "slipping" heresy.


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## wjs2nd (Mar 6, 2013)

consettbay2003 said:


> brown listerine might work but I found it almost impossible to get the pesky thrisps to gargle.



Hahaha:rollhappy: I force them to drink it.:evil:

lepetitmartien: you are right. That is why I use brown listerine from time to time. It has alcohol in it.


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## gonewild (Mar 6, 2013)

When I was in the 3rd grade one of my friends drank brown listerine and he Thriped out big time.


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## lepetitmartien (Mar 7, 2013)

There's 21% of ethanol in it… maybe it helped.


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