Paph leaf issue, next episode: gratrixianum

[musa]

Hi,
my gratrixianum hasent bloomed for 8 years now, therefor I neglected it completely and didn't mind if leaves were getting wet in caring for neighbouring plants. Now by chance I discovered a severe damage. I think It is bacterial infection (acidovorax?).
Should I throw it out right away or try to cure it? Thanks for your oppinion!

upper side of the leaf


and below




habit


black spotting on upper leave side. As these are not described for gratrixianum, are these already signs of infection?
I haven't realized them as they are similar to the spotting of the lower leaf side.

 

[Ozpaph]

spider mites???

 

[musa]

There are definitely no mites on it, I checked it with a microscope, no signs of it, no imago, larvae, egg or olf shells. What I could see is that the brown spots are wet and go on a bit within the parenchyme...

Off topic:
Anybody has an idea what function the usual spotting at the base of the leaves has? There are less to no stomata in that area.

 

[Ray]

I don’t know that this has any connection to any of the issues you’ve experienced, but I was talking to someone recently who has access to a low-magnification microscope, and he was telling me he was able to see all sorts of mites and/or small insects at 50x that were not seen with a 10x loupe.

 

[Hardwood]

this is an excellent source of information about leaf problems.
https://www.staugorchidsociety.org/culturepests-diseases.htm

 

[Ray]

this is an excellent source of information about leaf problems.
https://www.staugorchidsociety.org/culturepests-diseases.htm

Yes, it absolutely is... But getting a reliable ID by comparing photos with what's in front of you is almost as "iffy" as correctly ID-ing hybrids from their blossoms.

 

[musa]

Ray, I use a stereo microscope with 40 x magnification, that gives already a good view into the cellular structure of a leave, I guess it will be enough to find all sort of mites.

Harwood, thanks for the link, it looks like acidavorax could be right.

 

[richgarrison]

Yes, it absolutely is... But getting a reliable ID by comparing photos with what's in front of you is almost as "iffy" as correctly ID-ing hybrids from their blossoms.

Ya know.... thanx so much for saying that.. I've been thinking that for years... and get very stressed at not being able to diagnose problems...

this was soo much easier with 5 plants.. ;-) (but what fun is that!)

 

[Brabantia]

I have the same issue on a Paph. hirsutissimum. I treated with a maceration of powdered cinnamon in iso-propyl alcohol. I wait and see....

 

[Ray]

You can simply add about 15-20 ml powdered cinnamon to a 500ml bottle of isopropanol, wait overnight and filter out the sediment. It gives you a decent bactericide loaded with cinnamaldehyde, which is a mild bactericide and fairly effective fungicide.

If you want a stronger fungicide, use cinnamon leaf oil in alcohol instead - it contains eugenol.

 

[werner.freitag]

Ray, how to apply ?
is the solution stable ?

 

[musa]

Never heared of connamon leaf oil. Any idea where I can get it?

 

[Ray]

I buy it from Cinnamonvogue.com, but I don’t know where it might be available in Europe. Their stuff originates in Sri Lanka.

 

[Ray]

I just took a look at their website, and they claim the now ship to EU - but I have no idea the cost. A little goes a long way.

 

[werner.freitag]

Ray, how to apply ?
is the solution stable ?

any idea?

 

[musa]

Thanks, Ray!

 

[Ray]

Sorry...missed that.

It appears to be very chemically stable, and is sold in a glass bottle with sprayer. I have used the cinnamon leaf oil on both plants (1% in isopropanol - I have never tried it undiluted) and myself (straight from the bottle) to cure a persistent toenail fungus issue, amazing my doctor and dermatologist.

 

[werner.freitag]

thank you, worth trying

 

[southernbelle]

I don’t know that this has any connection to any of the issues you’ve experienced, but I was talking to someone recently who has access to a low-magnification microscope, and he was telling me he was able to see all sorts of mites and/or small insects at 50x that were not seen with a 10x loupe.

Ray, I concur. I’ve dealt with mites for years on other plants, roses, etc. I’ve never dealt with ones that are barely identifiable at 40 power. Only if I wipe the leaf with a Qtip with alcohol and study the Qtip, then they are squirming so I can see them as insects. A 60x magnifier helps, except it’s so hard to hold it still it’s frustrating. A 10x loupe is pretty worthless for orchids imo.

 

[fibre]

If I have a damage like this I do apply some portions of Amblyseius swirskii, cucumeris and barkeri. And it works. So it must be a sort of Mites, if you see it or not.