Pleione 2014

[erf]

Hello Gordon
Thank you for the link. This link and many more have been read the last few hours. I treat my bulbs every year against mites etc. Also I use new compost material  every year. I still think it is the fluctuating temperature last spring, that is the main reason of the problem. But should it be virus, it is not more than 20-30 bulbs that need to be disposed. I will survive that, though it is frustrating.
Regards Erling

[Maren]

Erling, what makes you think your pleiones have virus? can you post a picture for us to see the symptoms?

[erf]

Hello Maren
Yesterday I got a mail from another grower of pleione. He had been looking trough the pictures on my page on facebook.

https://www.facebook.com/PleioneWorld

He wrote that he suspected some of my plants were infected with virus. If you have a look a the pictures on the page he suspect the following plants:

Pln grandiflora 'yellow lib', pln Eiger, pln Shantung 'Silver Anniversary' , pln Snow Monkey, pln. Kilauea 'Hoopoo', pln Zeus Weinstein and pln. Alishan ' Merlin'.

About Pln. zeus Weinstein it might be true, since it has been discussed fore some time. I have isolated them and already bought new once from two different nurseries.

The rest I still think it is due to temperature problems last spring. But I will wait and see. When these clones are flowering I will post 'before an after pictures'.

Regards Erling

[SteveC2]

Like you I suspect temperature problems may have caused some of the problems with your flowers.  I do wonder if you are forcing them with too much heat.  They do seem to be very early flowering.  I am not sure where you are but last spring in the u.k. and I believe much of Europe was very cold.  Even at the end of March I had very little moving, my flowers finished well into June.

[Maren]

Hi Erling,

I wouldn't be so hasty about virus. Some of your plants look as if they went through a very dry period and maybe sudden increase in heat when the petals developed, therefore they are creased and a little deformed at times. I put this down to environmental conditions i.e. what you do to them, not what they are.
By the way, grandiflora 'yellow lip' has a 'p' at the end.

[erf]

Hi Maren and Steve
Thank you for your analysis. I am glad that you agree on heat problem. This year my spring growing condition has improved very much. So lets see what happens to the clones suspected.
I have not tried to force my plants by increasing heat, this was just the condition I had earlier on. This year I can keep temperature around 6-8 C, hope that this will do the trick. At least, the near future will show whether temperature had anything to do with it.

And Maren, I will correct the name. As you know, English is not my mother tongue. 

Regards Erling

[Luc Gilgemyn]

Hi Maren and Steve
Thank you for your analysis. I am glad that you agree on heat problem. This year my spring growing condition has improved very much. So lets see what happens to the clones suspected.
I have not tried to force my plants by increasing heat, this was just the condition I had earlier on. This year I can keep temperature around 6-8 C, hope that this will do the trick. At least, the near future will show whether temperature had anything to do with it.

And Maren, I will correct the name. As you know, English is not my mother tongue. 

Regards Erling

I have more or less the same conditions as you do, Erling.  I grow my Pleiones in a unheated but frostfree veranda where temperatures tend to fluctuate strongly depending on the weather.  As soon as the sun shines, temperature rises easilly to 20° C or more even when it's fairly cold outside.  Without sunshine temperatures remain low in wintertime and early spring.  When we get a sunny and warm period in the early stages of the growing season I have also experienced buds develloping to quickly with colour streaks as a result or the occacional bud aborting...
I agree with what has been said by others, I wouldn't be too worried about virus at the moment and await flowering conditions in the coming weeks and months...  Fingers crossed !

[Slug Killer]

Some Pleione hybrids do seem to suffer more than others. Pleione Eiger does not like temperature change and often has streaks if it comes in to flower too soon but is fine the following year assuming the temperature is favourable. It's as if the pigmentation gets bleached out. Now I know everyone says not to water Pleione until after flowering and roots are well developed but in some cases it's just not practical with higher than average temperatures. Could watering over developing buds also cause a problem?

Erling I can't see anything wrong with your grandiflora apart from its shape which again may have been caused by heat or even cold problems at some point. If going by your pictures then the Erebus Redpoll looks suspect as well.

The biggest problem as identified in an earlier post by Paul Cumbleton which talks about tests carried out by Ian Butterfield years ago is that not all virus infected plants show any signs and grow as well as non infected Pleione. Therefore without testing every plant in your collection it's impossible to say which ones are healthy. You could burn a plant that you suspect is carrying due to a few petal streaks but the culprit may sit quietly in your collection not noticed for years to come.

How easily and at what stage a virus can get transmitted from plant to plant is also questionable. If transmitted by mites then presumably a newly acquired bulb potted up and sitting close to an infected bulb could be infected and then show signs when flowering?

Fingers crossed all will be well this year.

[Bart]

Hello Tamar and welcome!

Flower colours in pleione hybrids can show some variation from season to season. P. Zeus Weinstein is well known for that. It sometimes produces colour breaks, depending on climate variability during the development of the flower bud.

Have a look at last year's discussion about it as well.

Last year I made my debut on this forum asking questions about this very issue (see my pics of P. Eiger a few posts down from the quote).
After the input received, I decided to put my pot full of Eiger in my woodland patch where they got eaten within days by an army of slugs...
 Then I visited the Malvern Spring Show and discussed this matter with Ian Butterfield. His point was that it might well have virus, but if it doesn't affect the others, and the plants are vigorous, what's the problem. I subsequently dug my Eiger's up,  and raised them away from others to see what happens this year. They suffered because of their outing, but I might still get a flower or to.  I'll post the pic as soon as I get one.
It is clear to me now that it isn't clear!

[Bart]

Just tried to answer, opening with a quote from last years' thread where the same issue arose. But it appeared as an answer in the 'Pleione 2013' thread, where it doesn't make sense. Maybe Maggi the magical moderator can help transporting it over? Sorry!

[Maggi Young]

No worries, Bart - it's now the post no.38 on this page 

[karel_t]

Because I‘m the person who sent the e-mail to Erling, that some of  his plants look oddly and in my opinion show symptoms similar to viral plants, let me to write a several words about viruses in pleiones collections.

Here on the forum and elsewhere, is the problem about viruses very often discussed and were written many about that, but basically no facts and between growers are too many myths about viruses.

As many of you know, I’ve make for several last years a research in cooperation with the Crop Research Institute Prague - Department of Virology about spread of virus in pleiones culture and their influence on plants. Let me to summarize in epitome the findings, which we have reached so far.

Between growers still survives an idea that viruses are not harmful for plants, if they only cause changes of the colour of flowers or leaves and don’t lead directly to death of the plant.

It’s truth that pleiones are probably very resistant to destructive effects of viruses and viral plants can grow very vigorously. This fact is probably due to their one-year growing cycle, so unlike an evergreen orchids have viruses in pleiones very short time for visible showing their presence.

Viruses in evergreen orchids are the most noticeable on old leaves. The young leaves are usually without any symptoms. If we transfer this fact onto pleiones life cycle, we can found some viral symptoms on the leaves only in late summer, so, at the time when the leaves begin to physiologically turn brown and fall, so it is very difficult to tell whether the changes on the leaves are caused by a virus or plant just finish its growth.
That’s way we only can observe the changes on the flowers. It is true that changes of colour and shape of flowers, etc. can cause a lot of factors, but viruses are one of them and is better to be careful than sorry.

The tests we’ve made show that some plants contain a virus in a latent stage, which has no effect on the plant until the plant is exposed to some stress. It may be for example a bad temperature condition during bud developing period. Thus, reacted mainly spherical viruses which were usually found on the plants without any symptoms. In contrast, the filamentous viruses, with particles length from 430 to 3300 nm such as CymMV caused colour or shape anomalies of flowers always, without regard to condition changing.

As I said, it appears that Pleiones compared to evergreen orchids are more resistant to the virus. It means that viruses spread slower through the pleione collection, however they spread. We performed experiments with transfering of a spherical virus from secretion of pleione which didn’t show any symptoms on a host plant (Chenopodium amaranticolor). Host plants show at month many viral lesions. Next transfer was performed on Phalaenopsis with the same secretion - the plant after 1/2 year showed spots on the leaves and subsequently died.
Likewise, I believe that there is no other reasonable explanation for “Sudden Dead Syndrome”, what has been many times debated here, than the virus impact in a latent stage.

Reluctance nurseries to test their plants is obvious. The tests are too expensive and testing in one way may not lead to the true result. We are always performed three kinds of tests as ELISA, electron microscopy and host plants and in many cases, we obtained different results.
The problem with the ELISA test is that it works only for one specific type of virus. The problem of electron microscopy is that you can monitoring only a small part of the plant and the problem of host plants is their own resistance to some viruses.

Another factor is the popularity. None of the nurseries like information that their plants are viral. Therefore, rather proclaim that viruses not harm, or that the problems causing other factors.

I believe that in this short post I’ve explained how serious problem may be the viruses in our collections. Therefore I recommend, all odd looking plants keep into quarantine.
Our project should be completed this year, so, after that I will publish more details or photos.

K.

[erf]

Hi Karel and all
Thank you for explaining. I amnot disputing your resurch at all and think that you are dooing a good job on that. As I wrote i my mail to you and on this forum, disputed plants in my collection has been removed from the others, and will be followed closely. You are right, better careful than sorry.

The problems I raise, is of corse that can I trust that every grower will do so. I have put a lot of efforts and money into building up a god collection, buying plants from recognised nurseries. If I shall be able to develop my collection further, I need to be able to sell surplus to buy new ones. If the health of my collection is doubted, I have a problem. I know of corse that this is very egoistic. 

So let me state here, that all my plants being suspected will stay in carenteen for at least two years, and I will post pictures of them every year on my own page. Should they flower and look odly again, I will destroy them. Anyone who have bought plants from me, of the ones disputed may write me a pm or a mail, and I will immediately refund all their money. That is the best I can do.

I do hope that all other serious nurseries will do the same.

Funny how things can change from day to day.

Frustrated but still a happy pleione collector

Erling

[karel_t]

Hi Erling,
We of course can’t to recognise the virus only by photo – we are not fortune-tellers. However is better to keep plants several years in quarantine than risk that virus will spread around all collection.
Ian Buttrefield told me, that he throws all oddly looking pleione out. I thing that positive selection is only one good way.
K.

[Maren]

Karel,

yes I agree with Ian Butterfield's approach to throwing out at harvesting time any pseudobulb that looks suspicious, having lesions, discolorations, black or brown pits etc. That will minimise bacterial and fungal disorders. As for virus, it's hard to tell, as already mentioned.