What Is This On My Paph?

[wilbeck]

I received this Paph. malipoense from Orchids Limited in spike aboout ten weeks ago. The bud rather suddenly died and I cut off the spike. There was some of this rusty stuff on the two lowest leaves (which died and were removed) when it arrived and the black spots you see on the others. The rusty stuff has now involved the youngest leaf. I would appreciate any information about the problem, its identity and how to treat it. Thanks. Here is a picture:

 

[gore42]

Ugh. I'd spray it with Phyton 27 if you have it, or Physan if you don't. Actually, first you should surgically remove it. Cut out all effected areas and then some. I can't tell from the photo what it is, but if it's getting worse, get rid of it as fast as you can.

- Matthew Gore

 

[wilbeck]

Phyton and Physan weren't available locally, so I bought a bottle of Consan 20, which, like Physan 20, is a 20% quaternary ammonium product. From reading directions elsewhere, it appears that I may even need to soak the plant and repot it in new mulch that has also been soaked in the stuff. Could the black spots and brown rot be botrytis?

 

[SlipperFan]

Phyton and Physan weren't available locally, so I bought a bottle of Consan 20, which, like Physan 20, is a 20% quaternary ammonium product. From reading directions elsewhere, it appears that I may even need to soak the plant and repot it in new mulch that has also been soaked in the stuff. Could the black spots and brown rot be botrytis?

No -- botrytis is a smut that you can easily wipe off with a little alcohol on a piece of cotton. It is something that seems to gravitate toward Cattleya, Dendrobium and a few others that are warm-humid growers. If you don't have the Phy...s, try spraying with hydrogen peroxide (after cutting off the rot) and when it dries, sprinkle cinnamon on the cut.

 

[Eric Muehlbauer]

I honestly can't tell you what that brown stuff is, but is it hard and dry? This is something that I freqently get on paphs, for some reason, always the innermost leaf...too close to the center to be able to cut out. The good news is, that in my experience, it is strictly a cosmetic problem. The dry brown area is restricted and does not spread, and eventually either grows further out as healthy leaf tissue grows in, or gets replaced by the next, healthy , leaf. I suspect it has to do with some kind of localised water damage....Take care, Eric

 

[Heather]

Is it wet and medicinal smelling? It doesn't look it. In my experience, Erwinia is wet and messy; unmistakenly so... and what Eric is saying is more reminiscent of what your photo shows than Erwinia. But that's just my experience and what I get from your photo....

 

[wilbeck]

Thanks all for the replies. I pulled the affected leaf off and will treat with the Cosan 20 and repot the thing and keep my fingers crossed.

 

[wilbeck]

It appears there is no cookbook answer, so, here's what I did: I repotted the plant in a 4in. terracotta orchid pot with the standard Repotme.com Paph-Phrag potting mix after cleaning off the roots, which didn't look bad to my untrained eye with no rot or mold, and after dunking the plant in a solution of the Cosan 20 at 1 tsp. per gallon water for two to three minutes and rinsing the potting mix in tap water followed by the diluted Cosan 20 solution. The plant, even the leaf I pulled smelled clean. Here's a picture of the nekkid Paph.:

 

[gore42]

Well, it looks like the plant is in good enough shape that it should pull through, as long as the infection hasn't spread beyond control.

- Matt