# Growing brown spot on leaf



## Hamlet (Nov 30, 2016)

Last week I noticed a brown spot on my Paph. philippinense var. album. I covered it in cinnamon powder to see if it would help, but now I see the spot has doubled in size. At this point I should probably remove the leaf completely, yes? Does this look bacterial, erwinia maybe?












There's another tiny spot on another leaf, should remove that as well? Should I treat with anything or would removing the affected tissue (or the whole leaf?) be enough?






Thank you!


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## Stone (Nov 30, 2016)

I wouldn't rush to remove the leaf. This sort of thing usually does not spread far. I would just keep an eye on it. If it stops spreading, leave it be.


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## Don I (Nov 30, 2016)

I hope everything ends well. I feel your pain.
Don


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## abax (Nov 30, 2016)

Order some Dragon's Blood from Eric and paint those spots
with it using a Q-Tip. I don't take chances with damage
like this.


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## Stone (Nov 30, 2016)

It's not a disease. You see this almost always after deflasking green leaved paphs. Even after 2 weeks sometimes. Usually the area remains green for quite a while then as the dead cells which have lost all their water collapse they turn brown. (naturally) Obviously for the seedlings out of flask, the cells are not protected by a thick enough cuticle. It seems to always happen on the top of the curve of the leaf. The area exposed to the brightest light (where the light strikes the leaf squarely). I believe that it is a combination of the leaf which has not hardened properly for whatever reason, together with light without the humidity. For example, with the seedlings out of flask, the light intensity does not change but there is a sudden huge drop in humidity from 100% to 60% or so. I think it is the cells being destroyed by UV light because they are not protected enough by a waxy cuticle. Usually there is no need for any further action. 
The cause on a more advanced seedling like this? Could be anything from a nutrition thing or different combination of light, heat and humidity to a plant which is unable to tolerate it.
It will adjust by itself. The only thing you need to do is watch for secondary infection but I've never seen that happen.

That's my theory anyway....


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## Hamlet (Dec 2, 2016)

abax said:


> Order some Dragon's Blood from Eric and paint those spots
> with it using a Q-Tip. I don't take chances with damage
> like this.



I see this stuff mentioned on here a lot, I should get some!



Stone said:


> It's not a disease. You see this almost always after deflasking green leaved paphs. Even after 2 weeks sometimes. Usually the area remains green for quite a while then as the dead cells which have lost all their water collapse they turn brown. (naturally) Obviously for the seedlings out of flask, the cells are not protected by a thick enough cuticle. It seems to always happen on the top of the curve of the leaf. The area exposed to the brightest light (where the light strikes the leaf squarely). I believe that it is a combination of the leaf which has not hardened properly for whatever reason, together with light without the humidity. For example, with the seedlings out of flask, the light intensity does not change but there is a sudden huge drop in humidity from 100% to 60% or so. I think it is the cells being destroyed by UV light because they are not protected enough by a waxy cuticle. Usually there is no need for any further action.
> The cause on a more advanced seedling like this? Could be anything from a nutrition thing or different combination of light, heat and humidity to a plant which is unable to tolerate it.
> It will adjust by itself. The only thing you need to do is watch for secondary infection but I've never seen that happen.
> 
> That's my theory anyway....



Thank you very much for this post! Now I'm glad I made this thread before removing the leaf. I hope you're right and it's not a disease.

This plant is years out of flask (25cm leaf span). The damage is just as you described, though. On the curve of the leaf, and it's only visible on top of the leaf, not below. The spot is hard and not soft or mushy like rot.

Maybe the damage was caused by the flow of warm, dry air from the heater under the windowsill. Half the plant was exposed to this airflow. I moved it to a new spot with a bit lower temps and higher humidity. Hopefully that will stop the damage from spreading.


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