Erwinia or minor infection?

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Well-Known Member
Aug 5, 2015
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Athens, Greece

Saw this on my P. kovachii this morning:

I applied a topical gram + and - antibiotic and the progress slowed down but it still is spreading, but quite slowly thankfully. Is this Erwinia or a minor rot of no consequence? That scale like leaf has been wrinkled since I got the plant a couple months back and I always expected that leaf to dehisce but the upper part of it has been healthy(the lower is dirty from the Erwinia infection it arrived with which ruined the mother rosette but I saved the pups with sanitation, hydrogen peroxide and antibiotics)and the lower has been hanging on with no active infection, till today morning(now it's night). Can I leave it there or shall I remove it? It's just that I have been waiting for it to bulk up and grow big and now I saw this, don't want to have to remove something yet again. If it's a minor infection, I would prefer to leave it dry there. Or I could bruise the damage on the surface to accelerate drying. Or just keep on the antibiotics till the plant kills the infection and infected tissues with its phenols

Thank you very much in advance!
The leaf was starting to yellow and the infection was moderately spreading, so I ended up removing the whole leaf. I see no infection below, did an antibiotic wash, dried the wound and the leaf bases below and hope all is clear again. The plant is growing well
I've been fighting this kind of bacterial infection on a couple
of Phrags. all summer. If the blotches return, get some
Dragon's Blood. I tried just about everything you've tried and the infection kept returning. The Dragon's Blood has
stopped it completely.
Thank you very much for your replies!

I agree Troy, it's probably that but it's currently indoors and airflow can only be so much indoors and close to windows. I don't wet the plant though.
I will try placing it in another spot that may allow a little more air circulation. If that doesn't solve it, I may have to get it outdoors again but I cleaned it when reporting and want to risk snails again

I will try getting some dragon's blood if it reoccurs. Do you apply that on top of the infection or do you still have to excise the infected tissues?
I don't see any real problem here. Maybe there is an "infection" on this dying lower leaf since many fungii and bacterias colonize dying or dead tissues. But most of the time they are unable to establish on a healthy plant.

You wrote the scale llike leaf has been wrinkle since a few months. Trying to rescue a shrivelling/yellowing leaf with such a spot is not a good idea IMO and if you apply antibiotics as soon you see a spot, the bacterias (if it is a bacteria) can become antibiotic resistant.

IMO such a small lower leaf dying is not really of concern ... Just remove it. If you are afraid of infection on the remaining growth, I would just apply dragon's blood or cinnamon.
I put the D's B directly on the affected area and put enough
to slide down into the area and down into the root zone.
Usually two or three drops does the trick if the area of bacterial infection isn't large.
Thank you very much Erythrone, great to know there was no real problem!I know exactly what you say, dying tissues are easily colonised by saprophytic microorganisms with no consequence for the plant usually as they have already been cut off by the plant.

Yes, that scale like leaf was wrinkled for months, but only the last day before removal did it start to yellow. It probably was its time to go as you said.

The rest of the plant is fine and growing well, no infection of the point of leaf dehiscence.

Thank you abax, i will keep it in mind and order some eventually
My newest P. kovachii arrived today with this on a couple of its leafs. What is it? I dont see any patterning on the newest leafs so i think that excludes virus. The seller told me that this happens in high temperatures and its probably mesophyll cell collapse. What do you think? I think he might be right about what it is but mine never did that in the high heat i grew it. It may be culture and fertilizer/water quality related maybe, such as too much K or too poor water in Ca or Mg making the leafs susceptible to it? Not sure but i think i should not see any of this under my care

In certain areas of a few leafs, i saw a yellow powder like covering the leaf underside in a patch. Thrips?

I also found orchid snails in the substrate. How do you deal with this and how do you get rid of them? I think they can damage orchid roots pretty extensively from what i have seen in other orchids of mine

Thank you very much in advance :)
I think I'd send the pictures to the seller. The vendor should send you either a replacement or your money back.
This discoloration and snails too is just too much crap to
be sending this to a buyer. I'd be quite angry if I received a plant with this kind of damage.
I did sent them asking for info on cause and what to do. Got a short reply about it. I can't say I am angry about the damage as it's something that tends to happen and kovachii hate the drying out 1 and a half weeks in the mail can do. Packing could have been different to keep it moister, but it was very well packed in general. I saw photos of the plant prior to shipment, the broken leafs were broken from back then and I can just barely discern that the dark discoloration on the leafs was present from then, but the angle of the photos doesn't allow easy viewing of it. Any idea what causes this? I am thinking malnutrition in conjunction to some kind of stressor as i see none of it on the new leafs. All ideas welcome :)

No matter from which orchid nursery I have purchased, orchid snails and slugs have been pretty universal hitchhikers with very few exceptions where I am pleasantly surprised! With a very thorough repot, I have gotten some of my orchids rid of them but it's not possible with all orchids as many retain a fair amount of medium stuck on the roots. I also don't like repotting just to get rid of the snails, if there is another way totally safe for the plant and non-toxic for me, it would be great
Thank you very much Erythrone, great to have some confirmation on it! This is past damage, not under my care, so its not saying me anything yet. The weather is cool currently, right in the good growing temperatures for this species and i let it enjoy the fresh, humid air(its been raining).

A Paphiopedilum callosum that arrived alongside with it, is starting to show some fresh damage on it, something like mesophyll collapse as well. Maybe from the dryness during the trip or maybe the parcel got exposed to heat during transit? No idea
The very beginning posts, anytime you see suspicious browning like that, it is best to trim off the affected leaf and keep a very close eye.
I think I see some mealy bugs although it is not clear. Perhaps a little piece of perlite or calcium deposit dried up on the leaf?

Regarding the new purchase, I am very picky and do not accept anything with marks and this seems to my preference, is shocking. lol
I have not seen this kind of things happen even in the over 90 summer days in my dry apartment.
Strange things can happen in the dark box during the shipping.
I would still trim that leaf (hopefully just one leaf?) and see if any more browning occurs.

Those little bush snails are such a pain for me as well, and many pots come loaded with them.
I think repotting is a great way of instantly getting rid of majority of the population. You will eventually see them again because tiny babies and eggs might be stuck on the root hair and other little bits of old mix that are stuck on the roots.

I have not tried any chemicals for bush snails, but I either repot, hand pick them out every night until I see none (I know this is tedious but works quite a bit). I also find drowning them works. You can soak the pot over night. This won't hurt the plants but snails will either crawl out or die inside the pots. Of course, some will survive, but I have had great success getting rid of them almost completely this way.

Regarding mail order, always contact the seller about the conditions of the plants. I have bought many via mail order although I do not like that because I prefer to buy in person after examining the plants myself very closely.

I have only had a couple of problems.
Trust me, don't keep any plants that came with browning. All the explanations are not exact diagnosis of what's really going on.
Most likely you are just getting sick plants and you will get more sick plants because of it eventually. Why not start fresh and clean? Things can only go wrong. Starting with clean and healthy plants and keeping them that way is easier and headache free.

Oh, and last, virus, just because there are no symptoms on the newer leaves does not mean anything. So there.
Thank you very much for your extensive reply, i truly appreciate it that you took the time to see my post through and reply :)

None of the plants have mealy bugs(for my original one i am sure, the other you never know till some days after) but there do are a few salt crystals from guttation and calcium deposits as well as soil and packing material remnants on the leafs which could appear like tiny progeny of mealy bugs.

I understand what you mean. I generally don't like marked leafs on orchids or any plant that holds the leafs for quite a while but its ''acceptable'' to me given that misfortunes can happen to any plant even under the best care. And even under our care. Getting a plant in awful condition in the mail is something that definitely happens unfortunately. Most orchid nurseries pack very well and plants arrive in tip top shape. But both P. kovackii arrived at awful condition, the first with Erwinia, from which it recovered/is recovering and the second the way you see it....

If you check thoroughly through the photos, there are numerous yellow and dying leafs which from my experience so far, i think are beyond repair and will eventually die soon. We are looking at least for 3 leafs gone and some scale like leafs.

But from what i just saw, we may have not seen the worst of its damages still....Here are some pictures taken just now:

Watersoaked areas have appeared on many leafs right out of the blue. At least i didn't remember seeing them before, maybe due to the dehydration of the plant.

Something else i saw is that the tissue of some good leafs is whitened close to the petiole junction. I thought this happens when a leaf is about to die and not on healthy ones, so i didn't like seeing it on the 3rd newest leaf

Is it senescence related here or declaration stemming from a deficiency/light deprivation, whatever?

The only good thing is that its leafs have perked up considerably and that its guttating all over now. I think it grew some as well.

Thank you very much for the tips on the snails. I have been hand picking them at night too but they are not always in visible spots. Some more ''jungly'' pots i have are difficult to hand pick too and the bark wants to float when i try soaking. I tried the beer lures one but no snail got caught. I will try looking for some natural enemies like certain nematodes which parasitise and kill them fast. I know this works wonders with slugs but i am not sure about the normal snails. I will ask and probably try them anyway as its easy and non-toxic for us and the plants.

Buying in person is not an option for me here as there are no orchid nurseries in Greece for species orchids, so everything i want, i have to mail order. I usually buy from nurseries i know well and i know the plants arrive in tip top shape and it never ceases to amaze me how well they pack even brittle inflorescences. But even from those nurseries, i have gotten plants that arrived with an Erwinia outbreak or had all roots dead rotten/dead. So it happens even in the best families as we say. The seller of my kovachii is very well reputed in this forum. I have sent him the above photos i posted to see.

I pretty much have no alternative but to keep any plants that arrive in whatever condition cause even a half dead one is better than none of a certain species i want to grow. And i manage to slowly nurse them back to health. Its certainly annoying and gets me out of my way to save them but most sellers are definitely not happy to replace plants no matter how they arrive. I don't blame them and don't push for that as they did sent a plant, as agreed. The transport took a beating on it which can't be attributed in a definite way to anyone, though a packing fitting the plant's humidity and water requirements *may* have helped it arrive in better shape. One never knows how a replacement will arrive either.
If i show you how my official palm imports from Florida frequently look like on arrival, you would cry... i know i do when i see them. Worse than old lettuce on a market shelf and way crispier... All these need a huge amount of TLC to bring back to life basically and many months or a few years of patience till they can look like something again. But you can't tell the seller much either, cause its either order and suck it up, or you can't order again... I still order...And i definitely hate everything about how the plants arrive but at least i can get to grow some of the species i like that are not source-able in Europe.

If you think there is something i can do in this particular case, i would love to hear it. I don't like flaming people and i am usually reluctant to demand something that would make me an unwanted buyer. I don't like excluding myself from useful sources because a plant arrived in bad shape. Still i hate it when it goes so wrong

What do you mean with browning, the brown marks on the live leaf? Here is a fresh photo

How can i exclude the possibility of virus? It doesn't seem viral to me, the pattern doesn't appear right but it would be much better to know for sure.

I never use runners on my orchids nor cut any green/live tissue, plus i don't expose any of the orchids to the water of another orchid, so chance of virus transmission should be very low in my collection. I always keep these standards and new plants are quarantined away from others than can share pathogens or pests.

Thank you very much again for your help :)
You mean the last picture with the brown marks? Would be great if virus can be excluded from a possibility

As for the water soaked spots, I also don't think this second plant has Erwinia but rather something else, possibly less aggressive. The seller told me that he has seen this when he imported the plants from Peruflora 2 years ago. Some leaf parts were lost but it didn't kill the plants. Lets see how it goes
The plant has resumed fast growth now and is growing multiple cm of new leaf per day. It's also guttating.
The yellowed leafs are drying and not getting infected. I hope it's on its way to recovery now and whatever damage it got, is mostly finished and not progressing much

Any insight as to what caused the watersoaked areas to suddenly appear? What could the brown spotting be from? It was great to have confirmation from Erythrone that the brown patterning seems like mesophyll collapse and not virus. Any more info on cause, why probably happened and how to prevent it, would be awesome :)

Thank you very much in advance
The plant has resumed fast growth now and is growing multiple cm of new leaf per day. It's also guttating.
The yellowed leafs are drying and not getting infected. I hope it's on its way to recovery now and whatever damage it got, is mostly finished and not progressing much

Any insight as to what caused the watersoaked areas to suddenly appear? What could the brown spotting be from? It was great to have confirmation from Erythrone that the brown patterning seems like mesophyll collapse and not virus. Any more info on cause, why probably happened and how to prevent it, would be awesome :)

Thank you very much in advance

The water soaked areas could be from ruptured cell walls caused by extreme water stress/pressure differential.

I dont think the brown is virus either, if it were the spots would probably be discolored yellow and not drying tissue.