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Author Topic: Pleione 2015  (Read 50840 times)

karel_t

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Re: Pleione 2015
« Reply #15 on: February 16, 2015, 03:15:55 PM »
Alex, which temperature changes do you mind? If you grow all your plants in the same conditions and this symptoms show only a few plants, and the others are OK, it means that something in the plant is wrong. If it would be a temperature, the same symptoms would be seen on the most of your currently flowering plants. If not, it is probably a disease.
As I already wrote here - in most of plants showed the similar symptoms, which we tested by electron microscopy during last three years in our research about Viruses in Pleione Culture, was detected a virus. All such odd-looking plants should be quarantined and tested.
K.
« Last Edit: February 16, 2015, 03:21:18 PM by karel_t »
Prague, Czech Republic
www.pleione.cz

SteveC2

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Re: Pleione 2015
« Reply #16 on: February 16, 2015, 05:52:14 PM »
Well that didn't take very long did it ;D.
Every year we have this discussion about viruses and having followed the topic in other years I must admit the V word shot into my head as soon as I saw the picture.
But, purely for discussion purpose, following on from Alex's thoughts, could the fact that the early flowering time suggests that these bulbs have been seriously forced at high temperatures have any effect?


Alex

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Re: Pleione 2015
« Reply #17 on: February 16, 2015, 09:45:40 PM »
Karel, one thing I'd disagree with there is the idea that if only a fraction of a group of plants shows changes they are likely to be non-environmental in origin. Changes are mostly the product of environment x genotype rather than just environment, and in a collection of diverse species and hybrids, it is quite possible that some could respond to environment in a way that others won't.

Steve, I hesitated for a while before posting in suggestion of "the v-word" because I too have read these threads before and we all know the score by now...but I was intrigued because the blotching is so similar to what I saw on my scopulorum, and I wondered if anyone had any information on this *specific* symptom.

Cheers,

Alex

Maren

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Re: Pleione 2015
« Reply #18 on: February 17, 2015, 09:13:18 AM »
Michal,
that is a very odd looking P. Cosmos 'Shooting Stars' indeed. And much earlier than my other ones, which hardly show a bud yet and flowered last year in mid March, a month later than yours. This makes me think that yours has been forced, which would also account for the slightly misshapen flower.
Forcing pleiones is not a good idea in my experience. I sometimes tried it to meet exhibition dates and had to leave the forced plants behind because they did not look good.
Virus is, of course, a possibility, but not a certainty. If my plants look like yours when they flower next month, you'll get your money back. I hope you think that's fair. :)
Maren in Marlow, Buckinghamshire, United Kingdom - Zone 8

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Tim Harberd

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Re: Pleione 2015
« Reply #19 on: February 17, 2015, 11:21:56 AM »
Pleione forcing is fraught with difficulty. I once gifted a Ducat to someone who was interested in having a yellow pleione.. They flowered it a full six weeks before me, and, reportedly, it had no yellow! Sadly they didn’t photograph the flower, which would have been interesting. I haven’t heard from them since… so I guess it is no more anyway.

Tim DH

karel_t

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Re: Pleione 2015
« Reply #20 on: February 17, 2015, 12:35:39 PM »
Steve, this is a very interesting idea, however a very difficult answer. If we would accept, that the changes on the plants were caused only by temperature or humidity shock, which of course could be possible, we must first ruled out that the plant is infected by virus .
Given that none of nurserymen doesn’t tests viruses in Pleiones systematically, there is a high probability that plants may contain a virus in a latent stage.
As our research has shown, there is a percentage of plants containing spherical viruses, that doesn’t show any symptoms (if the plant is grown in standard conditions). These plants multiply, bloom and grow normally. However, we don’t know what will happen when we expose the plant to a temperature or humidity stress. It may just be the tripper of virus activity. The same situation is with filamentous viruses (CymMV and ORV were detected just in a few tested samples).
In many cases of tested plants, the virus activity was showed after changing growing conditions. While nurserymen have seen no symptoms, in the buyer’s conditions we could find changes on the flowers and leaves and a virus was detected.
As I have already written, the virus can not be identified only from picture, but caution is always on the spot!

Maren, I also disagree with forcing Pleiones. I think that see, for example flowering P. formosana in February, is really crazy.
K.
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Michal Mikita

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Re: Pleione 2015
« Reply #21 on: February 17, 2015, 03:20:50 PM »
Michal,
that is a very odd looking P. Cosmos 'Shooting Stars' indeed. And much earlier than my other ones, which hardly show a bud yet and flowered last year in mid March, a month later than yours. This makes me think that yours has been forced, which would also account for the slightly misshapen flower.
Forcing pleiones is not a good idea in my experience. I sometimes tried it to meet exhibition dates and had to leave the forced plants behind because they did not look good.
Virus is, of course, a possibility, but not a certainty. If my plants look like yours when they flower next month, you'll get your money back. I hope you think that's fair. :)

Maren, English is not my mother tongue, but I'll try it. My pleiones are in a cold room, on windowsill, without direct sunlight. While other pleiones sleep or begin to grow, Pln. Cosmos 'Shooting Stars' is blooming. My pleiones didn't force. I still have something to learn ;) I enclose a photo od Pln. Cosmos 'Shooting Stars' from a different angle, and my windowsill with pleiones.
Michal Mikita, Banská Bystrica, Slovenská republika

Paul Cumbleton

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Re: Pleione 2015
« Reply #22 on: February 17, 2015, 04:47:40 PM »
Michael,
I agree with Karel that it is impossible to know for sure without a test if a plant has virus. And also agree that the effect of temperature isn't a simple factor; while some have observed that these symptoms can be caused by temperature (and so they think a virus is not involved), you have to ask what is it that the temperature is actually doing to cause this effect?

In my opinion, the most likely answer is that the temperature is affecting the level of activity of a virus. At one temperature virus activity may be high and symptoms appear, while at another temperature virus activity may be low and symptoms do not appear. This may be why the same plant may exhibit symptoms in one year but not the next. But again, this idea cannot be proven without testing.

Temperature can certainly directly affect the colour of the flowers, but in my experience this is an "even" affect, where you may get more pink  for example in flowers that are kept warmer. But colour changes that appear as blotches are I think much more likely to be due to virus.

I feel sorry for the poor nurserymen & other suppliers who may supply a plant that has not shown any problem for them but which under the different conditions of the purchaser produces these worrying symptoms.

Paul
Paul Cumbleton, Somerton, Somerset, U.K. Zone 8b (U.S. system plant hardiness zone)

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see http://ebay.eu/1n3uCgm

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Michal Mikita

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Re: Pleione 2015
« Reply #23 on: February 17, 2015, 05:02:00 PM »
Michael,
I agree with Karel that it is impossible to know for sure without a test if a plant has virus. And also agree that the effect of temperature isn't a simple factor; while some have observed that these symptoms can be caused by temperature (and so they think a virus is not involved), you have to ask what is it that the temperature is actually doing to cause this effect?

In my opinion, the most likely answer is that the temperature is affecting the level of activity of a virus. At one temperature virus activity may be high and symptoms appear, while at another temperature virus activity may be low and symptoms do not appear. This may be why the same plant may exhibit symptoms in one year but not the next. But again, this idea cannot be proven without testing.

Temperature can certainly directly affect the colour of the flowers, but in my experience this is an "even" affect, where you may get more pink  for example in flowers that are kept warmer. But colour changes that appear as blotches are I think much more likely to be due to virus.

I feel sorry for the poor nurserymen & other suppliers who may supply a plant that has not shown any problem for them but which under the different conditions of the purchaser produces these worrying symptoms.

Paul

Paul, thank you for your answer.

Michal
Michal Mikita, Banská Bystrica, Slovenská republika

goofy

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Re: Pleione 2015
« Reply #24 on: February 18, 2015, 11:25:17 AM »

Dieter, many of your photos are not now visible  - when I try to access them direct by their link, thisis the message I get ;
I hope that this will only be a temporary problem  and we will soon be able to enjoy your pictures again.

hello Maggi,
unfortunately I am not an "IT specialist",
so I dont understand why to acces my pics form their "LINKs".
and what do you want to "check" there?

They can be seen easily from the forum,
and indeed I really do not know about the problem.
()Khadija can see the pic of the "humilis for example)

maybe some earlier pics are already "deleted" from the server :(

BUT if you are interested in some special pics,
I can send them to you personally in "original size"

cheers

Maggi Young

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Re: Pleione 2015
« Reply #25 on: February 18, 2015, 12:04:16 PM »
Hello Dieter - it must have  been a temporary problem- because the photos are t showing again now.  When I wrote that message earlier I could see no picture, only an external link, which did not lead to the photo. All is now well!
Margaret Young in Aberdeen, North East Scotland Zone 7 -ish!

Editor: International Rock Gardener e-magazine

goofy

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Re: Pleione 2015
« Reply #26 on: February 18, 2015, 04:24:48 PM »
........All is now well!

tks Maggi,
that makes me happy :)

dieter

ashley

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Re: Pleione 2015
« Reply #27 on: February 22, 2015, 11:49:43 AM »
I  haven’t grown pleiones before but  recently received a pseudobulb of P. humilis which looks fine except that the developing flower bud has withered.  Does this affect its chances of producing a leaf bud and recovering?
Ashley Allshire, Cork, Ireland

Catwheazle

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Re: Pleione 2015
« Reply #28 on: February 22, 2015, 01:07:30 PM »
flowering now  ;D .... the first on my Pleiones this year.

Pleione forrestii

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Steve Garvie

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Re: Pleione 2015
« Reply #29 on: February 22, 2015, 01:08:03 PM »
No, not at all Ashley.

The pseudobulb was probably exposed to fluctuating temperatures after initial bud development causing the bud to abort, but leaf and root growth will be unaffected.

The critical period is when new roots start to develop -if the substrate is too damp the developing roots will rot; a bone-dry substrate doesn't work well either. Humilis naturally grows as an epiphyte/lithophyte in moss. I find it does well grown in living sphagnum within a vented plastic pot (I melt holes in the plastic pots using an old soldering bolt). Early in the season I keep the sphagnum just damp by misting the moss. When the new leaf has almost fully formed the pot can sit in a shallow saucer of water, this needs frequent top ups as the capillary draw of the sphagnum is surprisingly effective. Watering is best using rain water, be careful with feeding. Avoid urea/ammonium nitrogen sources and always flush well between feeds with rain water.
They like the same growing enviroment as petiolarid primulas but avoid frosting.
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Steve
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