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fmv how is it spread?

hi friends,
  it seems all figs that i have planted in the ground are disease free
however many potted plants given to me  do show signs of the virus.
can i contain it?

marcantonio

Not from what I have seen.

But you have the fig wasp in California to help spread the virus.
I'm still trying to figure out why aphids aren't supposedly a vector.  Do they suck fig sap and die?  (I've seen a number of dead bugs on fig leaves as Herman previously pointed out.)
I had read about fig mites, pruning, budding or grafting spreading virus.  But if we're very careful, folks in the NE (or fig wasp free areas) should be able to avoid spreading it.

From USDA / UC Davis "which some attribute to mite vectoring.". See http://www.websitetoolbox.com/tool/post/figs4funforum/vpost?id=2153298

Apparently the wasp is not considered the source of FMV transmission, so not having the wasp will not make you safe.

Hmmm.  "which some attribute" - doesn't sound like consensus to me. 
So now I don't know why aphids AND fig wasps aren't considered transmission culprits.

It doesn't really involve the vector, but something I read suggested that FMV is not evenly distributed throughout the entire plant and that is why apical meristem culture is capable of clearing the virus (not as much virus in the apical bud because of rapid growth). Anybody else hear of such?

OK, I had a post, but when I uploaded pictures both the post and pictures seemed to disappear.
Scott, I have heard this and believe it.  I've been pushing my plants and the fast new growth doesn't show much of the symptoms of FMV infection.
 One is Bayernfeige Violetta and the other Neveralla.

I hope you can see the pictures!  If not, somebody tell me what I did wrong, or better yet, how to do it right.  LOL

Scott,
I wonder if that is why only one branch of my "Jacks Quarter Pounder" is showing signs of FMV, even the new growth on that one branch show it (lightly) but the others don't. A sucker shoot that came up from the roots has shown no signs at all. Am still keeping it isolated from all my others trees though, just to be safe since none of the others had shown any symptoms.
Woody.

Woody,

Coulds be. I have a few trees that are growing quite well on some branches, and other branches are clearly inhibited in their growth and affected more by FMV. Some branches "outgrew" it later in the season. I have pix, but don't have them ready yet.

As an experiment it might be interesting to remove the sucker shoot after it has sent out some roots, pot it up and see if it shows any symptoms.  The one branch that does show symptoms has had them since the first leaf out this spring, so if I take the sucker off after the tree has gone dormant the stress of breaking dormancy next spring might be enough for it to show up in it too (or not). Either way I will have 2 JQP's.
Woody.

The shoot will probably be infected.  The virus is not present in large enough quantities for the leaves to show symptoms, but it is there.  Usually, just the growing tip of vigorously growing shoots is used to make new, virus free plants.  But it is so small, it isn't practical to use it outside of a labratory set up for micropropagation - tissue culture.  Cutting it off (with a little more shoot for ease in handling) and rooting it is possible, but not easy.  Researchers have treated these small fig cuttings with heat and "cleaned them up", but again it is not easy without specialized equipment.
I tried again to post the Bayernfeige picture, but the file is too large and I'm not skilled enough to resize it (any hints for the electronically impaired? LOL).  The new growth is now starting to show FMV symptoms.

I keep wondering about propagating cuttings under heat (some type of greenhouse arrangement) and then air layering the top of the cutting. Not to eliminate the virus, but to weaken it?? I kept noticing on the GW forum that people in warmer climates seemed to have better success with UC Davis cuttings and less trouble with FMV than those farther north did.

Scott,
This web site (probably already viewed by many searching for FMV answers) seems to advise using high temperatures and long photo period (16 hours light + 8 hours dark) with 5000 lux intensity. The temp range seems to be 98.6 F during the light and 93.2 in the dark. Average sunlight is 32000 to 100000 lux according to wikipedia ( might be a little difficult getting the sun to shine for exactly 16 hours). Of course they were using meristem material from buds in a culture medium in a lab environment. So maybe a combination of HID lighting plus high temps could serve to weaken the virus to a point that severely infected ones could become healthier. I wonder what the effects could be with a full 24 hours of light and high temps?
Any way enough of  my fig induced rambling, here is the web site: http://www.actahort.org/books/480/480_30.htm

Woody.

It doesn't seem likely that you'll weaken the virus.  If anything you'll be selecting for the hardiest strain - the weaker ones might die, leaving the strongest to survive and bounce back when the heat treatment stops. 
The Bayernfeige picture shows the virus load building up and starting to show symptoms - it was  clear previously.  The Neveralla looks clear at this point, but it's very likely the virus is present in smaller amounts.   
I think that trying to airlayer a new cutting will take too much time.  Even if the quick growth outstripped the virus, by the time you have rooted the cutting (3 + weeks ?), it will have caught up and infected it.
A possibility is taking the growing tip from a fast growing shoot and grafting it on virus free stock (F. palmata or palmata crosses?), growing it out quickly and taking successive cuttings doing the same thing.  Possibility.
Lighting for 24 hours will mess the plant up big time.  Plants know up from down - day from night.  If you make it day all the time they get confused and shut down.  It is a powerful tool that commercial growers use to their advantage to control plant size - but it has to be used very carefully.
I really think that figs can be cleaned up outside of a lab setting - but it will take a bunch of trial and error to figure out how to do it.

Jon thanks for the help.


Jon, I've been having computer problems for weeks - very odd occurences.  Thanks for the help.

The top picture is Bayernfeige Violetta with the new growth to the left, just starting to show discoloration along the veins.  The old growth is distorted and heavily mottled.
The second picture is Neveralla, with the new clean growth to the right.
The virus is slower than the vigorous growth, but it does catch up.

Fignut,
If a way of controlling FMV or possibly eliminating it without resorting to using a lab would be great. Many discoveries have been made by the weekend tinkerer and with the group of fig folks that frequent the forums anything is possible. If  a lab can eliminate it using quick growth conditions combined with heat therapy it at least shows that the virus has vulnerabilities. Who knows, it could be something like using a green cutting placed in a hydroponic setup (ebb and flow maybe in something like turface), a broad spectrum light and humidity control. The light would be able to provide more than enough heat. I have used a similar setup in an experiment with photo-period dependent  induced  flowering, starting  with  a full  24 hours of light  and then  switching to 16 hours light and 8 dark, then finally 8 light and 16 dark over a 90 day period (have not tried this with figs though).
Theorizing possibilities and attempting new things  is what  keeps us going in life, otherwise we go stagnant. You never know where a crazy idea can lead unless you follow it, friends of mine didn't believe  that  I could grow  figs  in Kansas City  until they  saw the pictures  and tasted  the figs! 
I might be crazy but it sure is fun!
Woody.


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