Pleiones -- Paul Cumbleton's hybrids

[Paul Cumbleton]

Erling, I have no list this year - note that the message below about a list is an old one from 2015

Paul

[Paul Cumbleton]

Many Pleione growers have been seeing increasing levels of virus infections in their collections. While I have always rigorously disposed of any plants with symptoms, this does not seem to have helped and this year has seen my collection with an unprecedented number of plants showing symptoms. Seeing so many spoilt flowers brings me little joy and therefore with some sadness I have decided to stop growing Pleiones.

My entire collection is going to a friend who has isolation facilities and he will grow them on to try and pick out any that still appear virus-free. Those plants he will then grow and hopefully propagate so that at least some of my hybrids will still continue to be available at some stage in the future.

While somewhat sad, I prefer to be positive about this; I have grown Pleione for over 30 years and had much pleasure from them. The space created means I can try growing new things, and less time spent re-potting hundreds of Pleione pots will give me much more time to develop the outside garden which I am much looking forward to. Onward and upwards!

Paul

[Maggi Young]

A sad time, Paul - but probably the wisest move.
Good that you have a positive attitude to the situation.

[Alex]

So sorry to hear this, Paul. I have been seriously worried by the virus problem for a few years now and the thought of stopping because of it has certainly crossed my mind. Do you think that a quarantine approach will be enough if it is true that virus can be completely dormant in an infected plant perhaps for years? Do you know if Karel's new test that he has mentioned is ready for use yet (experimental use only perhaps but still valuable)?

I have bought viruses material from more than one nursery this year and had one well established nurseryman simply deny the classic symptoms. It is so hard when you really can't trust even the bigger name suppliers.

On a related note, I really do hope very much that your wonderful hybrids are not lost to us. I adore the shades you have achieved and would love to grow some more of them some day.

Alex

[Paul Cumbleton]

Thanks Maggi & Alex.
Karel's work is ongoing and his testing of my plants contributed to the reasons I decided to give up. As you point out it has become increasingly clear that Pleione can have latent virus that is not expressed - at least not in certain conditions. These plants may be sold in good faith but then in a different micro climate with different treatment the virus may show. I feel sorry for the nurserymen who sell stock that seemed OK but then expresses virus in the new home of the purchaser. When I have sold plants I always did it in good faith and never offered anything I was remotely suspicious of - but it seems that is no longer sufficient and I don't want to risk spreading virus around even if inadvertently. No, quarantine on its own won't and whatever plants emerge from that looking clean will need testing to see if they truly are so.

Walking into a glasshouse and seeing many distorted and discoloured flowers and leaves is simply disheartening and this is my prime reason for calling it a day.

There are so many wonderful plants out there I'm sure I'll soon have other things to bring me joy!

Paul

[Alex]

It is all a bit depressing on the Pleione front. If your collection turned out to contain a lot of viral plants, including those not showing symptoms (I'm reading between the lines and making assumptions here, sorry if wrong!), then little hope for the rest of us to be clean it would seem.

I agree that here are lots of other great plants out there though....perhaps more Frits and SA bulbs and even a list of these in time? I am particularly keen on the Frits. Good luck with all of it in any case.

Alex

[Anders]

Paul, do you know if the latent Pleione vira can infect plants from other genera? Pleione with the slightest sign of virus infection always go straight to the garbage bin, but some of my Bletilla flowers looked a bit fishy this year, perhaps it wasn't because of the wet summer. And what about Liparis and Calanthe...and...and.... Very depressing.

Anders

[Alex]

Right, Anders, depressing it is because we are powerless as it stands. We can't identify the infected plants and have to just wait for symptoms to emerge wherever they do. 

THe only useful measure seems to be very regular spraying to prevent further spread. I've been spraying an oil-based agent every 2-4 weeks so hopefully that at least stops whatever plants are clean from being affected

[Tim Harberd]

Hi Guys,
         This all sounds very sad... I've almost given up on peonies (note the missing 'l' !!) for similar reasons.
   On the subject of Pleiones: How long ago do you reckon virus started to be a problem? I’ve not added any stock from outside sources for some years… and fortunately I don’t recognise Paul’s description of ‘seeing many distorted and discoloured flowers and leaves’ so maybe I’m free of the problem?

Tim DH

[ian mcdonald]

I only have a few Pleiones and they seem to be ok. The leaves are broad and green and the flowers were not distorted. Mine are grown in a sand tray in the greenhouse with a top dressing of chipped bark. They hardly get any feed. Perhaps they are more hardy against disease? Here,s hoping.

[erf]

And what about the future for Pleione. I am not willing to give up. I have fallen quite in love with this plant and visa versa . For sure we have to dispose of Pleione with is affected with virus and for sure this alone will not do the trick. I think that Pleione is a fantastic hobby and I will keep on to my collection. I will for sure dispose of anything that shows signs of disease as I always have, but I will for sure also still offer surplus bulbs for sale. I think that is the best one can do, and then we have to live with some amount of virus. But Pleione have still so many good moments to offer. Just my opinion. 
Best wishes
Erling

[karel_t]

Tim, there is very difficult to say if your healthy looking plants are really virus-free without testing.
Here is one example:
This Pleione scopulorum we tested by EM in September 2012, because one plant showed brown blotches on the leaves. I didn't expect any virus just bacterial infection - the result you can see on EM picture - potyvirus.
In the next years we tested more than 100 samples and many of them didn't show any visible symptoms.
Unfortunately I'm pretty sure that all pleione collections have at least one viral plant 

Paul, I'm sure you will find another treasures for your pleasure. I look forward to see your new plants in the garden next year
K.

[ian mcdonald]

Perhaps too much feed to improve the size of bulbs and flowers has resulted in weaker plants where disease is concerned? Maybe the plants should be grown in harder conditions to improve disease resistance? Perhaps Paul could try this regime with a few Pleiones?

[sjusovare]

Ian, I doubt feeding regime has any influence when it comes to virus unfortunately, either the plants are in contact of those virus through insect wounds, bark, water.. in which case they get contaminated (without necessarily showing signs during a long period, during which they can contaminate the others...), either they simply don't... It's not like animals who have a direct immune system allowing them to destroy the pathogens when they encounter it, in which case the general health is important

[johnw]

Julien - Actually in Nerine there are both species & cultivars that have latent virus.  Too much nitrogen and the virus appears but by with-holding nitrogen the symptoms can recede, sadly this applies to only a few.  There are those that seem permanently infected and yet perform and flower normally.

john