What is this brown blotching?

[Ernesto]

Found on a brachy x multi hybrid two days ago. Immediately moved away from the rest of my plants. What is it? I sprayed it down with Physan 20 and hoping it doesn’t progress. I’m also considering spraying everything else down with the stuff as a precaution but wanted to get some opinions here first. The only thing I could think it could be is the same bacterial infection I had on another Paph, which I sprayed with Physan and let dry with a fan— this plant was the closest one and maybe whatever the pathogen was blown over to it?

 

[musa]

I had similar irregular and sunken in forms on some leaves as well, only they stayed green. I was told these were caused by dryness. If your spots are dried al little further or if the brown color is a secondary infection I do not dare to say. Desinfection and quarantaine is certainly a good idea.
Is ist possible that bacterial infections can be "blown over"? I Thought touching was necessary? Hope that there is s.o. with more frofound knowledge than me...

 

[Ernesto]

I had similar irregular and sunken in forms on some leaves as well, only they stayed green. I was told these were caused by dryness. If your spots are dried al little further or if the brown color is a secondary infection I do not dare to say. Desinfection and quarantaine is certainly a good idea.
Is ist possible that bacterial infections can be "blown over"? I Thought touching was necessary? Hope that there is s.o. with more frofound knowledge than me...

Drying is definitely possible. Where the plant is positioned normally it was always the closest one to the fan.

 

[Ray]

My first thought was "mesophyll collapse" that is often caused by cold water hitting sun-warmed tissue.

 

[Ozpaph]

I think exactly like Ray, mesophyll collapse - tissue damage. Not infectious.

 

[SouthPark]

Just watch it like a hawk. It is probably not getting attacked by pathogen. But in your kit - consider some copper spray, and also consider monterey garden phos ---- in Australia, we have yates anti-rot phosacid.

Also - keep a tab on things like temperature change in the growing area - ie. does the plant experience a significant change of temperature in a fairly short space of time .... etc. Eg. growing area temperature change ....... or whether cold water or warm water is dumped on leaves all of a sudden, etc. Or - do the leaves get exposed to say relatively high temperature for long times?

 

[Ernesto]

I’ve been thinking about y’all’s replies and I think I know what could have happened. At night I’ve been opening the air vents to allow cold air into the basement so that I can get a temperature swing at night. My fans are located below this air vent, and this week I had them blowing directly on my plants (I watered late in the day and needed to dry my leaves before dark) and forgot to redirect the airflow away from them. I noticed this week another Paph (this time a brachy) exhibit mesophyll collapse, without the browning.

 

[SouthPark]

That's probably it. Fairly large temperature swing (in leaf etc) may be ok ..... within reasonable absolute temperature limits that is ------ as long as the swing is 'gradual enough' - relatively slowly. Too quick will probably lead to that the cell busting effect.

 

[Happypaphy7]

It is most likely infection. I water all over the plants and nothing like this happens. Yet, plants that were not wet on the leaves would develop something very much the same as this in the past. The ones affected were similar hybrids of multi x parvi (Delrosi) and multi x brachy (Woluwense). They spread when left alone, and they stop spreading further when I applied Dragon's Blood.
So you might want to try that if you have Dragon's Blood, or spray antifungal/antibacterial and see if it helps.

 

[SouthPark]

I wouldn't put "dragon's blood" on that big area heheheh. While dragon's blood might work on certain things, I reckon that putting it on a wide area of a leaf might well start 'eating away' the leaf - and end up worse than what we started with. But I'm all for the just-in-case move - of anti-fungal/anti-bacterial spray.

 

[Ozpaph]

it will be fine. Just watch.

 

[SouthPark]

I agree - it should be fine. The boundaries of the sunken patches are very well defined - doesn't appear at all to be 'spreading' patches - which could be nasty (spreading patches that is).

 

[NYEric]

I wouldn't put "dragon's blood" on that big area heheheh. While dragon's blood might work on certain things, I reckon that putting it on a wide area of a leaf might well start 'eating away' the leaf - and end up worse than what we started with. But I'm all for the just-in-case move - of anti-fungal/anti-bacterial spray.

Dragon's Blood does not eat anything, it heals by drying and protecting. Unfortunately, I don't think it would help with this problem.

 

[SouthPark]

Dragon's Blood does not eat anything, it heals by drying and protecting. Unfortunately, I don't think it would help with this problem.

Thanks Eric. I was assuming dragon's blood might contain other chemicals, such as say solvents. Thanks for mentioning it anyway. I read about your good experience with that substance for some sort of rot - very nice to read and know.

 

[southernbelle]

When I use Dragon's Blood on a spot I'm not sure about, it leave a distinct brown stain. Is this normal, or is it the type of DB I have?

 

[SouthPark]

When I use Dragon's Blood on a spot I'm not sure about, it leave a distinct brown stain. Is this normal, or is it the type of DB I have?

That will be normal. That substance leaves permanent stains. But the substance will likely take out any bacteria that is in contact with it.

 

[NYEric]

Thanks Eric. I was assuming dragon's blood might contain other chemicals, such as say solvents. Thanks for mentioning it anyway. I read about your good experience with that substance for some sort of rot - very nice to read and know.

I swear by the product, the pure sap of croton lechleri. Unfortunately there seem to be some dubious products on Amazon.