leaf forms in Wendy's Gold and Virus questions

[mark smyth]

I think the answer is yes, Anne.

What virus affects Iris reticulata?

[RolloP]

Crikey,questions questions, I will answer them as best I can.

 ronm -  Please don't get paranoid by viruses in Snowdrops. Their rate of spread is very slow. It is not the same as the driver of the no.32 bus sneezing and half the town gets flu 2 days later. Viruses have been in Snowdrops for very long time. At present 13 varieties out of 30 tested have been virus infected. The plant seems to be very tolerant of virus compared to other genera e.g. Narcissus, Nerine, Iris etc. In these genera the virus symptom is much more pronounced and therefore more able to have infected plants rogued out.

ChrisD - Only very few viruses can be spread by true seed, incl. pollen. Most, if not all, the Potyviruses
are spread by sap transmission, aphids,leaf hoppers etc. Most of the Cucumber Mosaic Virus strains are also spread by sap transmission, but a few can be seed transmitted ,incl.pollen. It is not known if any of the CMV strains in Snowdrops are seed transmitted. I suspect, if any, they are very few. However, virus particles can be spread by adhering to the out side of the seed, This I think is a much more likely pathway for virus to get into new seelings.

johnw - re-Stagonospora. There is a huge amount of research, worldwide, to find and develop new wide spectum fungicides. The main driver is the market for fungal control of Cereal and other crops worldwide.
Bacillus subtilis -Serenade, which is the QST 713 strain of B.subtilis, is available in the UK for control of Botrytis in soft fruit. I think this is the same strain which is available in North America. I think it controls Glume Blotch (Stagonospora sp.) in wheat in North America, so it may well be worth a try, if available, for Stagonospora control on Snowdrops.
  In Europe, Stagonospora on Narcissus is controlled by Azoxystrobin ( sold as Amistar), and is very effective. This is not available to private gardeners but most plant nurseries, estates and farms will have it in their Chemical cabinet.
 Viruses are not easily spread by casual contact. It would require the leaf surface to be broken to produce sap and similar in the recipient plant for the virus to be transmitted.

davey1970 - It is impossible to say for sure that all Snowdrops with green on their outer petals are infected with virus. By what I have seen so far, this may be a possibility. Only by testing all or most of these varieties will it be possible to know for sure.  6 out of 7 green tipped varieties, so far tested, have had virus confirmed.

 Martin Baxendale - Please see my reply to ChrisD.  Although some viruses can be spread by pollen, I would say that Stagonospora cannot be transmitted this way. The only way it might be possible if there were some fungal spores adhering to the outside of the seed coat.
 I would suspect that virus spread via pollen not the major source of infection to new seedlings, but strange things can happen in the natural world.

 annew -  Narcissus have about 15 or so viruses that can cause symptoms, and I don't know the situation regarding virus transmission via pollen on any of them.  Probably very few, if any.

johnw - With the current state of knowledge regarding virus in Snowdrops, it may well be a coincidence
that "Trym" and similar varieties are infected with CMV. It is reports of variance in the progeny of micro-chipped bulbs of these varieties that may indicate that it may be more that a coincidence. I don't know, the evidence is there - you decide.

annew - If my suspicions are correct, the quickest way to get a yellow "Trym" or a greentipped "Godfrey Owen", is to exchange as much sap as possible, from one to the other. This could be done by cutting a slice off one or more sides of  suitable bulbs and then sticking them together to see what transpires.

mark smyth - re virus in Iris reticulata. Probably one of the Iris mosaic viruses. There are, I think, 3 types.
 Mild,severe and something else. None of them have been found in Snowdrops.

[Martin Baxendale]

Rollo, thank you very, very much for taking the trouble to give us all such detailed and thorough answers. As a snowdrop breeder (and dabbler with crocus and narcissus) your answers have been very interesting, helpful, and reassuring.

[ronm]

Amazing stuff RolloP, thank you . Most interesting, and reassuring that someone is watching . I'll sleep better in my bed tonight.  .
But ...... if an aphid sucks on an infected Galanthus, and then on my clean Iris stocksii ( I wish !! ), can it transfer? I think so. Hence my 'Typhoid Mary' reference.
6 out of 7 is up there !

[Maggi Young]

Renaming this thread to reflect valuable Virus info.

[Hans J]

In last year Wolfgang and I have written anything about Azoxystrobin :
http://www.srgc.org.uk/forum/index.php?topic=6697.msg186134#msg186134

I hope it will find now more interest here ...

Hans

[johnw]

Hans  - There seems to be quite a few formulations of Callaflor Azoxystrobin on the site Wolgang mentioned. Which one do you use and can you tell us how far it goes?  I think it said makes 10 litres.

johnw

[Hans J]

John ,

here we have : Saprol ( for hobby gardeners )
http://www.celaflor.de/pilzkrankheiten/produkte/Gemuese-Pilzfrei-Saprol.html

or Ortiva ( for profi gardener )

I use 0,1 %  ( = 1 ml for 1 liter )

Today just back from spraying my Galanthus - the temperatur is now 15° ....so it is possible to spray ..under this temperatur it makes no sense because the plants can not use it ( it is a systemic fungicid )

Hans

[ronm]

Are we drifting somewhat towards fungi now?
Not that this information is not valuable ... of course it is.

[Maggi Young]

Hans J was replying to Rollo's point about the carrying of fungus on pollen, and the use of various chemicals to prevent this.
Since there is a possibility that virus and fungal infections may be transmitted in ways that we may, as yet, not fully understand,  there is scope for "cross fertilisation" of these matters, I think.

[ronm]

accepted, 

[RolloP]

Some wires got crossed here.
 Azoxystrobin is a fungicide developed from an antagonistic fungus and is effective as a wide spectrum fungicide which includes Stagonospora on Snowdrop bulbs and foliage.
 It may be available for private gardeners on the continent but is only available to professional growers and farmers in the UK.

[annew]

Thank you for the information, Rollo. I rather fancy the challenge of doing a Dr Frankenstein and grafting 2 bulbs of, say, Trym and Wendy's Gold together to see what happens.
I need to find a henchman called Igor. Any applicants?

[Alan_b]

Well I'd certainly rather dig up Trym and Wendy's Gold than the things Igor had to dig up.

[ChrisD]

Thank you for the information, Rollo. I rather fancy the challenge of doing a Dr Frankenstein and grafting 2 bulbs of, say, Trym and Wendy's Gold together to see what happens.
I need to find a henchman called Igor. Any applicants?

Sounds like a fascinating experiment - I will change my name 

Igor