What is that?

[rauhaariger]

Does anyone know what that is, it is an intermediate form of drying up and rotting, especially on soft-leaved Phragmipedia like besseae, besseae hybrids but also on Limoinierianum and others. The young shoots are particularly affected. If it hits the heart leaf, the shoot is destroyed.

Thank you for your help!

 

[treefrog]

I wish to know too!!!! This has been a nightmare with my besseae hybrids too. For most of my plants, switching them to a sphagnum moss based substrate helped a lot.

 

[big923cattleya]

According to the Saint Augustine Orchid Society web site, it looks a lot like Psuedomonas sp. a fungal disease. Clip and treat with cinnamon or any other suitable fungicides. Improve air movement.

 

[Ray]

It’s tough to diagnose some things. My first thought was pseudomonas as well - a bacterial disease - but anthracnose, a fungal infection, may look similar.

A treatment with a copper-based product can help with either.

 

[big923cattleya]

Gosh, I always thought it was fungal. My bad.
No doubt these diagnoses can get tricky. Sometimes the more i look into it, the harder it gets.

 

[richgarrison]

in my experience, and knowing these are phrags (with a couple hundred of them growing in my greenhouse)... they weren't getting enough water at some point in their life cycle. could be because the roots aren't in good shape, or just because they weren't watered as frequently as they desired. Again in my experience (in my greenhouse) this isn't a disease related symptom.

Fix the watering issue and cut off the offensive looking parts of the leaf with a sterile blade.... and move on... should be easily solveable.

 

[mrhappyrotter]

they weren't getting enough water at some point in their life cycle.

I agree. Whenever it happens to plants in my collection, I can pretty much always narrow it down to a cultural issue (ex: the saucer dried up and I didn't notice).

The terminology for these symptoms that I tend to use is "vascular collapse". Not sure if that's actually scientifically accurate, though.

Although it can appear in almost any Phrag, I notice that it's a bit more prevalent in phrags with longer rhizomes and is a bit more likely to occur on newer growths before they have had a chance to root -- especially for the ones that like to reach for the sky.

 

[rauhaariger]

Thank you very much, that helps a lot. I can confirm that it is particularly common in freshly potted plants and in plants that were previously in poor condition. Couldn't it be that it is still a fungus that prefers to attack the weakened plant?

 

[cnycharles]

I’ve seen very similar on phrags I’ve incorrectly watered and dried too much, it looks like dry down damage

Different diseases (and insects) can affect weak tissue; some when the leaf is still alive and others when the tissue is mostly or completely dead

 

[richgarrison]

Thank you very much, that helps a lot. I can confirm that it is particularly common in freshly potted plants and in plants that were previously in poor condition. Couldn't it be that it is still a fungus that prefers to attack the weakened plant?

Not a plant physiologist and I don’t even play one on TV.. but I can say that in my collection, not only do these symptoms not spread to other plants, the symptoms don’t spread on the same plant once the plant is given the water it needs.

 

[gonewild]

Not a plant physiologist and I don’t even play one on TV.. but I can say that in my collection, not only do these symptoms not spread to other plants, the symptoms don’t spread on the same plant once the plant is given the water it needs.

My experience as well.