Spotting on leafs

[andre]

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.



Sent from my iPad using Tapatalk

 

[troy]

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

 

[andre]

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


Sent from my iPad using Tapatalk

 

[Justin]

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

 

[andre]

So the captan should do the trick then.


Sent from my iPad using Tapatalk

 

[eggshells]

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.

 

[Erythrone]

So you think it is anthracnose, Eggshell?

 

[eggshells]

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

 

[Erythrone]

Colletotrichum is a fungus oke:

 

[eggshells]

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

 

[troy]

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

 

[lepetitmartien]

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)

 

[abax]

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

 

[troy]

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

 

[lepetitmartien]

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.

 

[Bjorn]

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

 

[andre]

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

 

[eggshells]

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.

 

[SlipperFan]

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.

 

[Ozpaph]

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