Need help/odd phrag spots turning transparent

[Krister Lawlor]

Hey guys, I have some worries about my phrag Saint Ouen. It has some brown spotting, but that’s not my biggest worry.

I worry most about these odd spots on the underside of the leaves that are turning a darker green but are turning translucent.

The topside of the leaves dont seem to change though. Attached are some pictures of the plant from topview, underview, and underview that is backlit.

Id really appreciate your help! Thanks!

 

[Ray]

An infection of some sort. Personally, I'd treat it with Inocucor Garden Solution, as it acts as a broad spectrum bactericide/fungicide and is nontoxic.

 

[Krister Lawlor]

An infection of some sort. Personally, I'd treat it with Inocucor Garden Solution, as it acts as a broad spectrum bactericide/fungicide and is nontoxic.

Hey, Ray,
Thanks for the reply. How should I apply -a fungicide/bacteriacide to my phrag? Should I just spray the leaves or soak the whole plant?

I also have a confession.. im using really crappy miracle gro fir bark and I think it was already decomposing because Im now seeing some white mold on top of the substrate after only two weeks.. Should I just repot too? I have some ultra fine orchiata bark I could pot it with. Would I treat the roots too?

 

[Krister Lawlor]

Heres a better photo now that its in better lighting. I can see the vesicles of the leaf now when backlit and its has that oddly straight line separating healthy tissue from not healthy. This is the largest spot, but there are littler spots on almost every other leaf on the plant

 

[Ray]

Spray every surface of the plant and soak the potting medium.

If you go with the Inocucor product, which is a probiotic comprised of about a dozen live, beneficial bacteria and fungi, I suggest that you unpot the plant, immerse it in the solution for several hours, then pot it up, watering it in with more of the soak solution. Keep some in a spray bottle, and for the next several days - up to a week - spray the leaves a couple of times a day.

 

[abax]

I wonder if Dragon's Bloom applied topically might
be of some help.

 

[Krister Lawlor]

I wonder if Dragon's Bloom applied topically might
be of some help.

I see this Dragons Blood a lot on the forums but I dont know what it is? Im assuming its some herbal topical?

 

[richgarrison]

looks like either erwinia or pseudomonas... (see Sue Bottoms article here "orchid pests and diseases")

the one thing to consider immediately is to isolate it from your other plants. most of these kinds of diseases are transmitted to other plants just by water splashing off the affected leaves. Also typically once infected, the affected tissue doesn't 'heal'. The most you can hope for is that it doesn't spread into the crown. Removing the affected tissue with sterile cutting equipment is what many of us do. and do something to treat wound once you cut the leaf. cinnamon, powdered neem leaves, etc...

 

[Ray]

FWIW, I got a case of erwinia on a phal once, and the Inocucor treatment stopped it cold.

 

[richgarrison]

Ray

in that particular case, did the affected area eventually collapse, leaving a permanent lesion?

 

[Ray]

Ray

in that particular case, did the affected area eventually collapse, leaving a permanent lesion?

Of course - nothing rebuilds damaged tissue - but it stopped it cold, and erwinia can be really aggressive.

 

[NYEric]

Umm, is it physical or cold damage?

 

[Krister Lawlor]

Umm, is it physical or cold damage?

Honestly, I'm not sure. I've heard that it is a lot of things, but it isn't spreading and I believe the spots have been there for a long time. I haven't touched the plant with any fungicides, only a quick alcohol rub. The spots are not soft and feel the same as the rest of the plant, the only difference being a transparent discoloration of the vesicles. Currently, I'm leaning on a nutritional deficiency being the cause..

I don't remember if the plant was outside last winter or not. If it were cold damage, I'd expect more death spots and decaying matter. This plant isn't really showing much decay though..

There is a new growth shoot growing like mad right now and I have been giving it proper nutrients for healthy growth. It does not show any symptoms like the mother plant, so that is good and gives me reason to believe the plant will be fine and I can just leave it as is.

Still wish I knew the cause for it, though

 

[JasonG]

I had very similar damage on a large besseae a couple of years ago. I never did discover if it was an infection but the plant fully recovered. There we some theories that it was an over hydration issue.

 

[Ray]

I had very similar damage on a large besseae a couple of years ago. I never did discover if it was an infection but the plant fully recovered. There we some theories that it was an over hydration issue.

Can anyone explain how a plant can get over hydrated?

I suppose that if it was over-fertilized, the excess salt content of the vascular fluids might cause the absorption of excess water to compensate, but that seems unlikely. Besides I fed my plants at 125 ppm N MSU RO for several years and never saw that - of course, I saw very little blooming, too!

 

[Spencer Garing]

Can anyone explain how a plant can get over hydrated?

I suppose that if it was over-fertilized, the excess salt content of the vascular fluids might cause the absorption of excess water to compensate, but that seems unlikely. Besides I fed my plants at 125 ppm N MSU RO for several years and never saw that - of course, I saw very little blooming, too!

oedema- I've only ever dealt with it in kratky-hydroponic plants. possible in orchids but sunken spots indicate bacteria:

https://staugorchidsociety.org/PDF/EdemaBlistersonOrchidsbySueBottom.pdf

http://www.missouribotanicalgarden..../pests-and-problems/environmental/oedema.aspx

 

[Ray]

Yes, I've read both of those before, and while they both claim to explain the reason for the symptom, I am still at a loss I fully understand what would cause a plant to take up more water than it needs.

I grew lots of plants in semi-hydro culture (with unlimited water), including all my slippers, in a well-sealed greenhouse which often had RH over 90%. If there ever was a condition in which the plants' ability to use or transpire the water was limited, that was it, and so by the conclusion of those articles, I should have had a very edema-prone collection, yet I've never seen it.

 

[Ray]

OK. I dug out a plant pathology book, and in a section on environmental factors that lead to disease, there was reference to the fact that damaged root cells, usually as a result of suffocation, can lose their selective permeability, potentially allowing the uptake of toxic levels of metals (like nutrients built up in the medium, perhaps?) or other poisons that can disrupt the "water-balancing" capabilities of a healthy plant.

Is that the explanation? You got me.

 

[Spencer Garing]

yeah I don't have a good handle on how exactly edema occurs. this looks to be bacterial rot, I had the exact same (looking) issue on a new growth of rossioglossum. soaked it in inocucor and the spot turned black but still grew normally.

 

[Ray]

The section I referred-to earlier also mentioned the likelihood that root damage can "open the door" to pathogens that had previously been held at bay by healthy tissues.

So... I suppose this means that "too much water causing edema" is akin to "overwatering causing root rot" - it doesn't do so directly, but the symptom is a result of a side-effect of doing so.