Multifloral rot

[Rick]

I think that was good that you resurrected the topic of asprin Naoki. I've not experienced any conclusive help from it, but I wouldn't leave anything off the table.

 

[SlipperKing]

I'm going to go ahead and jump in here for support of Rick's ideas of elemental relations. Its a well know fact and its been mentioned here before that K is one of the mobile elements within plant tissue. As plants discard their old leaves, K is being relocated into the new tissues. Its my understanding potassium (K) is involved in 50-60 different enzymatic reactions within any given plant so it needs to be mobile. The fact plants keep their K probably is one of the reasons you find very little in the "environment" It is in the environment but its in plants not the dirt Back to the rot issue, I maybe wrong but the way I look at the K, Ca, Mg relationship is; in an unnatural environment, say a greenhouse, feeding too much K throws the balance out of whack. The plant cannot shed off K so it has to store it somewhere. What better place then where Ca and Mg go? Hence, weaken cell walls do to the wrong element. Soft weak growth ready for the eating(rotting).
I had two plants rot this summer, both with poor environmental conditions but not the fed water. M. Koopowitz with bad media-saved. A malipoense with poor light and air movement- may loose.
I've been following Rick's Klite. At first I started out at 100ppm N as I had with the old fert. Still lots of rot but the new leaves were shinny and a nice green. The more the forum discussed the issue of Klite I dropped my fert concentration down to the 50-60ppm N range then 20-30 range but very third watering. Currently I'm at 5-10 ppm of total N each watering which means the P and K is very low. I'm seeing tremendous growth in all Paph species, esp. strap-leafs. Two reasons for lowering the total nitrogen to the 5-10 range, Lance's reports coming out of Peru and at Rick's recommendation.

I've put a number of plants, mostly species, into baskets (less then a year) and I'm happy to report good progress so far. Two randsii seedlings from Sam with his wire twist-tie roots have put on nice roots. The better one has double in size. A BS single growth of Dollgoldi I had previous rot issues with has cleared up since putting into a basket.

I think a 2 year commitment is needed with the Klite trial. Time to clear the toxic levels of K out of your collection, time to get pass side issues such as rot and to see if plants you never bloomed actually do!

That's my 2 cents.

 

[Rick]

Thanks Rick. Given the size of your collection, 2 plants in a summer would seem very low compared to what we've commiserated with over the years.

For me some of the bigger numbers are with seedling success rates. The first year out of flask or compot I would loose much more than now. It's almost a curse these days with flasklings and compots piling up all over the GH.

 

[Trithor]

Thanks all for the response. Yes it was my suspicion that it was erwinia, but I am unaware of a specific treatment for it other than a bonfire. So as I said, I started with the steps that I can control. I removed the plants from the greenhouse, unpotted them, paid special attention to washing out the root zone, and soaked the plant in a Captab suspension for half an hour or so (I always believe that infections tend to be mixed, so if I can remove the fungal component, I am dealing with plain erwinia) I let the plants dry on a rack outdoors over night. I have just finished potting them into fresh mix, and have placed them back on the rack outdoors. The asprin is something I had not considered, so off to the local superette to get Asprin and cinnamon. I am unsure how well powdered cinnamon will work (I have not had any success in the past, so I will buy both powdered cinnamon which I will dust all affected areas, and cinnamon bark which I will steep in warm water and place in a small spray bottle and spray the affected plants once or twice a day).
I am not aware of any change in any conditions in the greenhouse, other than as we go into Spring, the temperatures are obviously rising (perhaps the temp increase and more frequent watering has been the trigger) My greenhouse is still split into two treatments, Low K and regular K zones. Both sides have been equally affected. I am wondering if I should not supplement Ca, as our council water is very low in both Ca and Mg? Perhaps I should add small amounts of calcium and Magnesium nitrate to the water tank?(I run council water into a 2000liter tank which has home made carbon filter on its inflow (in an attempt to remove Chlorine and Flourides from the water).
Well off to the shops I go........

 

[Trithor]

Here are some of the pics

Firstly some of the plants affected (infected?)
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A pic of another plants leaf tip (this from a kolo)
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This pic showing a roths with the base affected, and the plant next to it with a problem at its base. The plants have all received cinnamon and asprin. Later I am going to spray them with my cinnamon extract.
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[Justin]

that one on the far right in the bottom pic next to the roth, with the rot in its crown looks like a goner. I would pitch that plant before it spreads

i feel your pain!

if you can get it, Phyton 27 is effective. A similar copper spray may help.

Ca and Mg are a must for multis...

 

[Rick]

Gary

Something that is generally not characteristic of Erwinia is for the infection to start in the middle or end of a leaf. Generally it starts in an axial and works outward along the leaf (surgery is tough in this case).

The kolo leaf pictured and the smell you described sure looks like Erwinia, but weird to see it at the distal end of the leaf. At least that is easy to cut off without affecting the base of the plant.

I've seen some odd things like this in Spring when still running heaters, but fluctuating cool mornings. I was concerned that condensation dripping off of hanging plants or the GH ceiling was hitting the plants with concentrated nasty bugs.

 

[Trithor]

Rick, at this time of the year our humidity is very low. I only water early mornings, and may wet the floor during the day. I try to dry the plants by sundown, even if it means opening the doors to dry before the cool of evening. There are no drips at this time of the year, but they might start as general humidity rises in about a fortnight or so. I posted the pic of the kolo leaf tip as it was atypical of the rest of the infections. I thought that could have come from infection of a damaged area (the plants are so damned big, this plant measures 1.4m across and gets bumped all the time) I tried to cut the leaf with adequate clear tissue.
All the plants have now had a spray of cinnamon extract, and are starting a course of clindamycin in the morning

 

[Ozpaph]

cut back the watering in the GH and add a fan or two.

 

[slipperscout]

Bacterial rot in all orchids

In my experience drenching the plants with dilute Physan (0.5-1) tsp/gallon in early September and repeated early in October will markedly reduce the incidence of bacterial rot of the new soft growth of phals and paphs here in northen New Jersey. Coupled with very good air circulation the fall Physan drench will control this problem remarkedly well.

 

[TyroneGenade]

This looks very much like what I was fighting. Start watering with bleach (5 mL domestos in 5 L of water) and hope the infection will stop spreading. Infected plants may be irrecoverable. I suppose the best would be to cut away infected tissue and soak the plants in the bleach solution. I found new growth was especially sensitive and the leaves could rot literally overnight. For some strange reason my insigne and Leeanum were totally resistant.

I suppose increasing the Ca and Mg in the feed might also help in disease resistance.

I suggest you go through your plants and look at them very carefully. Don't hesitate to tug on new leaves. I found the leaves looked OK but if tugged on slightly they would come loose and you could that they were rotten. Try to remove all plants with signs of rot.

 

[John M]

Something that is generally not characteristic of Erwinia is for the infection to start in the middle or end of a leaf. Generally it starts in an axial and works outward along the leaf (surgery is tough in this case).

The kolo leaf pictured and the smell you described sure looks like Erwinia, but weird to see it at the distal end of the leaf. At least that is easy to cut off without affecting the base of the plant.

I agree. Odd that the rot is starting in the middle and the end of the leaves.

Do NOT throw anything out, even if ALL the leaves are lost. I've had Paphs with this lose all but one leaf, barely hanging on and the rhizome eventually sent up a nice, new growth. They grow quickly because there is still a full adult root system feeding the new growth. It's not like starting from a seedling.

I don't see the use in sprinkling the Cinnamon on the surface of the leaves. Cinnamon is powdered tree bark. Tree bark has natural anti-rot properties. That's why it's so durable in nature. I use Cinnamon to dust on moist wounds that are exposed to the air. Dusting it onto a leaf that has soft rot inside; but, the "wet" rot isn't exposed to the air, really isn't going to be affected. You need to remove all the rotted tissue and dust the leftover, healthy; but, freshly exposed tissue with the Cinnamon to get the protective effect. I don't know what "Cinnamon Tea" would do, if anything.

Be VERY, VERY careful if you decide to water your plants with Bleach. I'd never do that for any reason. I tried to sterilize my rainwater holding tank with bleach about 18 years ago. I was told to do it by someone at Agriculture Canada. What a mistake! My plants suffered horribly! The bleach burns the plants and throws the pH WA-AAAAAAAY out of whack. My plants turned yellow and became stunted and generally looked awful for months, until they grew out of it. The pH swing dramatically interupted the plant's ability to absorb nutrients. The plants literally starved for weeks and that showed up as bright yellow new growth and a sickly green on the old growths. I'll never, ever do that again.

To sum up - here's my advice (What I do):
Any rot on the mid section or end of a leaf should be cut off.....cut well into the heathy tissue.

For growths with rot at the base, peel the leaves off one at a time, from the outside - in, right down to where they join the rhizome. Keep peeling until you get ALL the affected leaves. If that means all the leaves are removed and nothing is left but a stump on the rhizome; so be it. Spray the freshly damaged tissue where the leaves were removed with No-Damp, or some similar anti fungal / anti-bacterial spray (Physan?...3% hydrogen peroxide?). Dust liberally with Cinnamon powder. Place plant in increased air movement. Allow to dry thoroughly. The next day, spray the entire plant, including both sides of all leaves with Aspirin water. You can even drench the pot with the Aspirin water as well. Keep the plant in good light and in a fresh, boyant atmosphere with lots of air movement. Watch closely. Respray with No-Damp (or other), in a day or two. Respray with Aspirin water in a week.

If the plant is in bloom, pollinate a flower. I have NO IDEA why this works; but, whenever I've had a Paph with Erwinia that was in bloom, no matter how much of the plant that was lost, the rot stopped dead in it's tracks as soon as I pollinated one of the flowers. I once had a Paph. liemianum that was gorgeous. It was multi growth and in bloom with one spike. It got Erwinia. It lost growth after growth until finally, all the growths were gone except the one in bloom. Then the foliage on that growth began to rot as well. All the leaves were lost and I was left with a pot full of roots and a leafless flower stem. Not a single leave was left; but, there was a rather large green bract on the stem; that's it for green. I selfed the flower and cut off the growing point to prevent more sequential blooming. The rot stopped suddenly. The capsule fattened and grew. New growths began emerging from the leafless rhizome. As the capsule was nearing harvesting age (~9 months), the plant had a couple of nice, healthy new growths well on the way. It's a nice plant again; albeit, not as big; but, very healthy and rot free. I'll get blooms again next year, I expect. This was a plant that most people would've just tossed and given up on. Never give up unless all the tissue and rhizome and roots are dead.

I had a similar thing happen to a spectacular Paph. St. Swithin last winter. It was in bloom and it started getting Erwinia. I'd get it to stop...and then it would start up again. Finally as a last ditch effort to save the plant, when all the other growths were gone and half of the leaves on the blooming growth had been lost, I selfed a flower. The rot stopped dead in it's tracks and the capsule grew and ripened normally and was harvested recently. The plant is now putting up 5 new fans; all coming from the base of the bloomed growth which has just 3 small, remaining leaves.

Good luck!

 

[gonewild]

If the plant is in bloom, pollinate a flower. I have NO IDEA why this works; but, whenever I've had a Paph with Erwinia that was in bloom, no matter how much of the plant that was lost, the rot stopped dead in it's tracks as soon as I pollinated one of the flowers.

This is an interesting observation. Perhaps when the plant begins to develop the fertilized seeds it translocates potassium from the leaf tissue to the developing seedpod. Or some other minerals get transferred that causes the leaf tissue to become unfavorable to the infecting pathogen.

 

[TyroneGenade]

This is an interesting observation. Perhaps when the plant begins to develop the fertilized seeds it translocates potassium from the leaf tissue to the developing seedpod. Or some other minerals get transferred that causes the leaf tissue to become unfavorable to the infecting pathogen.

Or it starts producing something (a plant hormone) that increases the plant's immune system or that stunts the bacteria? Many possibles.

I had no trouble with dilute bleach and it did seem to slow the infectious agent provided I kept watering constantly. I suppose H2O2 with a little detergent would also work and break down quickly into something harmless. Another option is glutaraldehyde. It is used as a surface sterilant as well as a carbon source for plants. The down side is that it is very toxic in concentrated form and needs to be handled with care. The fumes are more toxic than the liquid. It can be bought in South Africa as Seachem Excel. The plant aquarium folks (such as myself) use it as a carbon source and general purpose algaecide. At the manufacturers instructed dose it is very effective and should be safe. You may actually want to use a higher dose. You can safely (i.e. nothing dies outright other than algae) dose up to 3x the recommended dose. You will need to add a wetting agent like Sunlight Soap. I want to repeat myself here: this stuff can be very dangerous so you have to work with it deliberately and carefully. No enclosed spaces!

 

[John M]

Or it starts producing something (a plant hormone) that increases the plant's immune system or that stunts the bacteria? Many possibles. There's definitely something going on like you and Lance suggest. The reason why I pollinated the liemianum flower in the first place was to try to get a green pod go far enough along to get viable seed embryos. However, to my astonishment, the rot stopped and the rhizome began to sprout new leaf fans....AND it carried the capsule to full term! And like I said, now I've got a nice plant again. Shocking! So, finding out that selfing a flower was a way to halt the rot, was a happy accident. I had given up on the mother plant and just thought I'd be lucky to get some seeds. However, because it worked with that plant, I deliberatley selfed the St. Swithin with the hopes that the rot would somehow be halted.....and it was! Now, I've got the seeds AND a plant well on it's way to a great comeback.

I had no trouble with dilute bleach and it did seem to slow the infectious agent provided I kept watering constantly. The issue is probably the dilution rate. Clearly, it was too strong for my plants. I was not happy with the "scientist" at Ag-Can!

..

 

[gonewild]

Or it starts producing something (a plant hormone) that increases the plant's immune system or that stunts the bacteria? Many possibles.

Do plants have immune systems?

If it is the result of produced hormones then someone needs to discover the hormone compound!

 

[abax]

Might Cleary's 3336 be effective against Erwinia?

 

[naoki]

It is a very interesting observation, John. As Tyrone said, there are fair number of hormonal changes due to fruits (e.g. auxin and downstream ethylene). It would be very interesting to find out why fruit bearing plants can escape from infection.

Lance, yes, the plants do have "immune" system, but they are not MHC (major histocompatibility) based:

http://www.nature.com/nature/journal/v444/n7117/full/nature05286.html

 

[naoki]

I know we are talking about Erwinia, but it's interesting that this nature review paper talks that one species of Pseudomonas (not sure if it is the same species for orchids) produces jasmonic acid mimic (which suppress salycilic acid based defense system). So for this, it sounds like aspirin "could" help.

 

[John M]

Interested in the Aspirin method of preventing and stopping rot? Read this thread. http://http://www.slippertalk.com/forum/showthread.php?t=25983&highlight=aspirin

Although, I'm not now as much exclusively an ASA user (I started dusting with Cinnamon or Sulfer again and I've started using No-Damp first, then following with the ASA spray the next day), I still consider the ASA a major component in my arsenal against rots.