Undiagnosed Leave problem in need of your help :[

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Biomedical Scientist
Sep 15, 2011
Reaction score
Hong Kong
Hi All,

I have encountered a problem with the leaves of my bellatulum alba. I have it for almost a year and previously it did not show any symptom like this.

Two of the recently matured leaves show patches with different sizes near the tip of the leaf. They are just like scars. They are brownish and dry. They emerge very slowly. And they only appear on those "new leaves" after I own the plant.

Since this is a slow process, I did not really remember when it get started. I assume this has been going on for a while since 2 months ago. Because of these features I assume I can rule out soft rot. I am thinking of the possibility of Anthracnose. However I really cannot give myself an answer to that even after some researches. This plant is so expensive so I need your help before anything goes bad.

I grow it under light, 20W purplish fluorescence. Now in summer i approximately water it once every 4 days. I use tap water but the tap water here is soft water. So I am kind of wondering if there's any Ca/Mg deficiency. But that does not explain why my other plants all appear normal. I grow it in mixture of perlite and charcoal, fertilizing 20-20-20, 1:2500 dilution approximately once every 3 weeks. Humidity is between 50 and 70%. Temperature now at night down to 20 degrees while in daytime up to 28-29 degrees. There's a fan running 12 hours in the daytime. At night I switch on AC so the AC would just do the same thing as the fan does.

1st Leaf. The most problematic one. Brown dried patch with little sign of merging the other patches. I draw a line around the patch with a marker for ease to monitor the infection process.

2nd leaf is having the same problem but less serious

Also the 2nd leaf. A different angle to take the picture.

3rd leaf. Seems healthy but there are small sunken areas which might proceed to the brown patches

The plant overall
You should check for red spider mites with a magnifiying lens. I use End All II insecticidal soap when I have this kind of problem. Fungus or bacteria usually do the damage far more quickly.
First what is that stick like thing on top of the media? Is that a fertilizer stick? Like urea foam sticks.
Maybe this has been happening longer than you think. I just noticed in the picture of the second leaf, the leaf under that one( a older leaf) has alot of sunken brown areas, they are just not as big as the other ones.
I think it might be nutrition related.

I see a few good looking root starts, but what do the rest of the roots look like? Ca only goes up through the roots and if the roots are poor, and you are using a standard high potassium fertilizer then you might be seeing a calcium deficiency.

Also brachy species coming from limestone areas may be more prone to K overdose. They are notorious for being "salt intolerant" even though many of them come from places exposed to ocean spray.

Sea water has lots of sodium chloride and magnesium sulfate. Although it has 400+ ppm of K, the K is buried by the amount of Mg, Ca, and Na.
i don't think it's nutrition-related. I have two plants that do this as well; they did it with their previous owners in their previous mix, and have continued to exhibit these symptoms in my greenhouse and in my mix. These are old plants and have done this for years. I can't seem to grow them out of it; the previous owner has not been able to grow his divisions out of it either, despite years of trying. The plants are Tiger Hill 'Royale Gleam' and Song-Bird 'South River', both awarded in the early 1980s. As far as I can tell it's not bugs, it's not fungal (or is resistant to a number of fungicides), I can't believe it's cultural (due to the experiences of the previous owners and because I have lots of other complexes right nearby without these symptoms) and I as well would love to know what it is.
The close-up of the bottom leaf does look like spider mite damage, but the other two leaves sunken brown areas don't have that appearance to me. Since those spots are near the tip of the leaf, but not at the tips, I think those are either nutritional or perhaps mechanical, like maybe sun damage after water sat on the leaf and became a magnifying glass? I've seen water damage that looks a lot like this in the greenhouse where I volunteer.
I think your nutrition is an issue. the leaves look a little pale and this could be caused by a poor root system? Also I believe albas cant tolerate as much light as normal varieties.
One thing is for sure, you have or have had mites (not you, the plant:)) so you should spray the entire collection a couple of times.
I would cut off the damage, (although maybe not needed), stop feeding and increase shade(?) and have a close look at your fertilizing regime as Rick suggests.
Cut the feed by 3/4 for a while when your sure the plant is growing. It won't starve.
I think these like to be grown rather hard for long term survival in my short experience with brachys.
Stone, would you please explain "grown rather hard?" I
haven't a clue as to what that means. Since the majority of my Paphs. are brachys, the statement is important to me.
Thank you all of you for giving me clues to rethink all the possibilities causing this.

I have to agree with Shiva, SLipperFan and Stone about red mites. They have been colonizing the plant before I own it based on the scars on the older leaves. However I don't think now red mite is the culprit behind this since the patches on those new leaves are somewhat different from the ordinary damages caused by red mites. Besides I regularly spray miticides (once a month or so) on all of my Paphs since March of this year. The patches appeared afterwards. So the red mite problem should be put under control and should affect minimally.

Summing up all of the your precious comments, I do agree that the patches now presumably indiciate one or more of the following problems:
1). nutritional
2). mechanical
3). Colonal (Inborn error?)

I agree with Rick and I am going to follow Stone's idea, to reduce the fertilizing frequency, and to supply more soluble Ca/Mg. And see how's that goes on afterwards.

I also agree with Slipperfan and Tim that the patches might refer to mechanical or inborn problem. I have been misting my Paphs more often when lights are on. And I have been spraying Neem oil recently. The two of them might cause some damages over the leaf cells. Let me try reducing these practices on this plant to see how it goes on.

Keep bringing up ideas, to stimulate my thinking about my cultivation. Really thank you all. I will keep updating the plant's status.
one possibility, not mentioned so far. Damage from a sensitivity to cold water. I did see this in my own collection. If I watered with cold water, especially in already cool weather, some Paphs, but not all would develop these types of spots of damage. Paph sanderianum seemed particularly sensitive to cool water. By cold I mean 55 F and the grow room was in the low 70's. The warm growing species had the problems. Some individual clones more so than others.

And of course, once the damage occurs all manner of fungi and bacteria will take hold in secondary infections/infestations.

Since then I installed a way to mix hot and cold water by using garden hose repair kits to reverse the male/female hose ends and a Y valve normally used to split the outflow from a faucet, I have had no repeat of this phenomena. I still occasionally have other pest problems, but the tissue collapse seems to have stopped. I mix the water to room temperature to slightly warmer than room temperature, especially in winter.
after reading all of this, you have a few things that could cause problems. cold water, off-feed and a few others have been mentioned; there could also be problems with particular plants that have been exposed to 1) neem oil, contact problem 2) pesticide damage - both could happen if the plant is too warm or cold, usually too warm and neem or pesticides are applied. some plants may show problems with some chemicals and not other plants/chemicals. though, damage under a leaf is usually pests/disease
Stone, would you please explain "grown rather hard?"
When I see a plant with hard, succulent or leathery leaves, I usually asume it has evolved to withstand rather extreme conditions for at least part of the year. Usually it involves a period of drought but it could be harsh light or drying wind.
If you look at brachypetalum (and some others) you see this tough succulent type of leaf, especially with niveum and godyefroyae but also to a lesser degree with concolor and bellatulum.
So by growing hard I mean less fertilizer (especially N), generally more light, greater air movement, a longer drying period between waterings and a definate dry (ish) rest during winter with plenty of light.
All this as opposed to how we treat the lush deep green ''leafmold'' type paphs which can take more N, shade, water etc.
Thats the way I see it anyway.
I also agree with Slipperfan and Tim that the patches might refer to mechanical or inborn problem. I have been misting my Paphs more often when lights are on. And I have been spraying Neem oil recently. The two of them might cause some damages over the leaf cells. Let me try reducing these practices on this plant to see how it goes on. .......
Isn't Neem a big no-no with brachys? I'm quite sure Nick Tannaci recommends not using it.
Ah, I finally found your reply to my question Stone. Thank
you so much. I didn't do this last winter, but I will this winter which is not that far away. KY winters are usually rather mild, but gloomy and overcast. Since I couldn't
think of a way to make my gh brighter, I placed mirrors
underneath my Paphs. cut to fit between the rows of plants. I don't see much in the way of improvement, but
it's only been two weeks. So "hard" it will be!
Thanks Leo. I have to pay more attention during winter. For now, the water seems fine. I would think it is a bit too warm for paphs. I guess over 25 degrees.

I agree with you goldenrose. Neem might be the higher possible culprit behind the problem. However since my 9 other brachys dont show symptom like this so I was not considering the damage brought by neem beforehand. I will cut down the use of neem on all the brachys and see.
Hi forks,

After a couple of days, I discovered that the other leaf, with less serious sunken brownish dry patches, has been worsening. The sunken area has expanded beyond the marker circle. Thereby I would confirm this as an infection.

Summing up all the ideas, I now could conclude this is a red spider mite attack followed by secondary fungal infection.

I have cut the infected areas, sterilizing the wound, and sprayed all my collection (targeting undersides of leaves) with bactericide, fungicide and miticide - a mixture solution in a slightly higher dilution (approximately 1:2000)



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