Phragmipedium disease

[Jaljala]

I have had this disease on a Phrag Hanne Popow for more than 2 years now, it keeps coming back and I am not sure how to get rid of it. The plant had a similar spot on a leaf when I got it and it did not expand at first. Then it appeared on a new leaf, which I removed quickly. I tried several treatments for bacterial infection (which I think it is...) and it kept the disease from spreading further.
Eventually a new growth started and was exempt from the spots, so I got rid of the old growth.
Then it came back... that growth still bloomed properly and the disease stayed quiet for a while. Now another new growth is almost mature and developed the spots again... removed all parts infected and treated with H2O2.

I was thinking of Erwinia, but if it was that I think the plant would be long gone already... any imput would be much appreciated. And it does'nt smell of rot, nor it is wet. The parts of the leaves that are affected are dry to the touch. On the pictures , an old leaf on the left had the spot for more than a year, and on the right is the new leaf I removed.

 

[NYEric]

Let me know if you want to try Dragon"s Blood.

 

[SlipperFan]

Eric once mentioned a dusting of a combination of powdered lime and cinnamon. I've had some success with it.

 

[abax]

I've seen that on a couple of 4N plants in my collection and used
DB and it hasn't spread and new growths are clean. Mine looked just
like your examples though less developed. I still don't know what
caused it, but DB seems to clear it up.

 

[troy]

It's brought on by some sort of stress, the stress weakens the plant, bessea does not grow very well warm to hot, I found my bessaes prone to this from growing to warm, overfertilizing, and lacque of fresh air flow

 

[Jaljala]

Thank you all for your answers!
Eric, i'll PM you if you box isn't full...

 

[John M]

'Looks like a Bacterial rot. Forget H2O2. That is a topical and this disease is systemic.

Remover ALL affected tissue. Spray entire plant thoroughly (top and underside of ALL remaining leaves), with Aspirin water (one 325 mg tablet disolved in 1 litre of water). A pill will disolve within minutes into a pile of granules....like white sand. The granules take longer to disolve into solution. I use a hand-held spray bottle. I add a dozen glass marbles to help break up and pulverized the ASA granules when I swirl and shake the spray bottle. I also take off the nozzle tip so that the solution is not atomized; but rather, it comes out in gentle shots of liquid (instead of a mist), every time you squeeze the trigger. If you don't take the atomizing tip off, tiny granules that don't get broken down will clog it.

Spray the plant once a day, for about 3 days. Also, immediately after the first spraying, dust the wounds with liberal amounts of pure cinnamon. Then, place the plant where it gets MORE air movement and MORE light. Most of the time, this will solve your problem. Also, Phrags hate old, sour potting medium. Keep your Phrags up to date with a regular repotting schedule. Best is to do it annually, or at least, every 2 years.

However, you should also review your culture. Something stressed the plant enough to make it susceptible to the disease. Make sure you are not feeding too often. About once every 2 to 4 weeks at 1/4 strength is good enough. Do not overfeed calcium. That causes micronutrient deficiencies which lowers the plant's ability to resist opportunistic pathogens such as this bacterial disease.

If the plant is in spike, self a flower. I have done this with about a couple dozen Paphs and Phrags, so far. Contrary to popular beleif, carrying a capsule does not weaken a plant and make it less able to fight off disease, it stimulates a plant to work harder at fighting systemic disease. Every single plant that I was having rot problems with that was in bloom and I was able to set a capsule on, has immediately stopped having rot problems and gone on to mature the capsule and recover from the rot. It's almost as if once you give the plant a "purpose" in life (to produce a future generation), it has a greater will to live. I'm not sure of the mechanism; but, I do know it's worked for me 100% of the time that I've tried it. In the case of multiflorals, or sequential bloomers, I remove the extra flowers/growing point, to allow the plant to spend energy only on producing the one capsule. I currently have a number of Phrags at the moment that had Erwinia and which got down to just one or two leaves, with a flowering stem. I selfed a flower, broke off the rest and treated as described above. Again, as expected, the rot stopped and the plants are not only growing a capsule, they're putting up nice new growths, too.

 

[Linus_Cello]

If the plant is in spike, self a flower. I have done this with about a couple dozen Paphs and Phrags, so far. Contrary to popular beleif, carrying a capsule does not weaken a plant and make it less able to fight off disease, it stimulates a plant to work harder at fighting systemic disease. Every single plant that I was having rot problems with that was in bloom and I was able to set a capsule on, has immediately stopped having rot problems and gone on to mature the capsule and recover from the rot. It's almost as if once you give the plant a "purpose" in life (to produce a future generation), it has a greater will to live. I'm not sure of the mechanism; but, I do know it's worked for me 100% of the time that I've tried it. In the case of multiflorals, or sequential bloomers, I remove the extra flowers/growing point, to allow the plant to spend energy only on producing the one capsule. I currently have a number of Phrags at the moment that had Erwinia and which got down to just one or two leaves, with a flowering stem. I selfed a flower, broke off the rest and treated as described above. Again, as expected, the rot stopped and the plants are not only growing a capsule, they're putting up nice new growths, too.

Fascinating tip. Thanks!

 

[Jaljala]

Thank you John, great info! I'm already doing lost of what you say though...(aside from selfing the flower, will give it a try if it blooms again)

 

[abax]

John, that's a very interesting approach to the problem.
Perhaps I'm just lazy, but I tend to just grab my DB and
hope it works. It usually does.

 

[eteson]

Does it smell like rotten potatoes? If the answer is yes it is erwinia... you can use dragon blood but also try to find the root of the problem. It could be not enough light or more likely not enough temperature oscillation between day and night.
The tip of selfing it works very well as was said by John.

 

[Rick]

Contrary to popular beleif, carrying a capsule does not weaken a plant

How long have I been saying this John:sob:

 

[Jaljala]

Does it smell like rotten potatoes? If the answer is yes it is erwinia... you can use dragon blood but also try to find the root of the problem. It could be not enough light or more likely not enough temperature oscillation between day and night.
The tip of selfing it works very well as was said by John.

No there is no smell...
I am hoping it will bloom soon, the main growth if almost mature and a small bud of a new growth is visible...

 

[Rick]

Do not overfeed calcium. That causes micronutrient deficiencies which lowers the plant's ability to resist opportunistic pathogens such as this bacterial disease.
.

John the priority of cation antagonism in plants is ammonium > potassium >
magnesium>calcium. So before implicating calcium as a cause of micronutrient deficiency you have 3 way more powerful trace metal blockers to look out for.

Also during a plant immune response the plant normally tries to dump K in favor of Ca (required for strong cell wall growth to combat spread through tissues. A ways back I posted a link to Dr. Eastewood's work showing that plants with low tissue Ca (high K) were unable to withstand erwinia or botyritus challenges. Plants with the converse were able to withstand the disease challenges.
http://www.fluidfertilizer.com/pastart/pdf/36p16-19.pdf
However I would agree that calcareous materials (i.e. calcium carbonate) in the potting mix are capable of absorbing metals and phosphorus, and a high pH caused by the alkalinity released by pH buffering materials will also make it difficult for the plants to uptake micros.

So need to be specific about form of calcium salt applied. Calcium nitrate, calcium sulfate (gypsum) and calcium chloride do not alter pH and do not bind micros in the potting mix.

 

[littlefrog]

Rick, would you use CaCl2 as a supplement? I've always heard that chlorine is bad for plants... Never was sure why though, it might be a myth. CaCl2 is dirt easy thing to find, though, at least around Michigan in the winter.

 

[Ray]

Don't do it, Rob.

I've got several 5# bags of calcium nitrate to part with at greatly discounted pricing before I move... (I'm closing the store this weekend.)

 

[Rick]

Rick, would you use CaCl2 as a supplement? I've always heard that chlorine is bad for plants... Never was sure why though, it might be a myth. CaCl2 is dirt easy thing to find, though, at least around Michigan in the winter.

CaCl2 provides the chloride (salt) of the halogen and not the oxidizing disinfectant (chlorine or hypochlorite) form. So not really a big deal.

However, I'd use either calcium nitrate or calcium sulfate. And if you are already applying a fertilizer with nitrate in it, then I'd opt for the sulfate salt (otherwise known as gypsum).

If you use calcium nitrate (like Brandon Tan at Huntingon does) then don't add other fertilizers.

 

[NYEric]

You know what to treat it with.

 

[littlefrog]

Don't do it, Rob.

I've got several 5# bags of calcium nitrate to part with at greatly discounted pricing before I move... (I'm closing the store this weekend.)

I actually have some calcium nitrate I've never used, but I'll take a few more. You know where to send it, send me a bill.

 

[Ray]

Please,place your order online, Rob. I need that "independent record" (i.e., not documented by me) for the accountant.

Someone else here already grabbed a bag.