Disease symptoms on Phalaenopsis- and (upcoming) lab-confirmed diagnosis

[camille1585]

I have been battling against a few diseases on the majority of my Phal collection for the past couple of years. I am in the process of throwing out most of them (due to disease and also a never ending mealybug problem- but that’s an entirely different story).

But before throwing them out, I will, at last, find out what these diseases are. I started a new job in May, and the institut runs one of the main daignostic labs in the country. There is budget for personal projects, and I have greedy colleagues eager to get their hands on my diseased Phals…. I thought I would share this process with you, since having definitive diagnostics to match symptoms could be useful for other people.

I'm hoping that by knowing what pathogens are causing this, I can take steps to change things in my growing setup/conditions to prevent it from happening again once I restart my home collection.

So I have given them samples from 5 plants (photos in this order), representative of the general health status of all my phals :
Phal bastianii
Phal mannii ‘Dark’
Phal gigantea,
Phal Liodoro
Phal equestris x maculata

Before testing I suspected that the black spots were likely to be bacterial- probably Acidovorax cattleyae. I also suspect that my Phal gigantea is virused- on some of the older leaves there were tell-tale ringspots, and in the photo here the ringspot marks eventually got covered by generalized leaf pitting. The biggest mystery however, is what is the pathogen causing the pitting (spots and streaks). That one has by far caused me the biggest headache and spread to nearly all my Phals, even if they were on the other side of the room or a different room!

I’ll have the results in a week or two since private work is low priority, and it’s also going to take some time to run the full battery of tests. For any pathogen not already in their database they might not be able to get a pathogen ID more precise than genus level. (Still good enough for me!)

I’ll update this post once I have new information!