So I posted this in Jon's seedling topic, but it got lost.  Nobody got the message.  What do you think?  Does heat really kill FMV?

Remember my Panachee that had no more than 2-3 leaves for 3 years?  Jon, you suggested moving the pot to a shadier place and dousing it good with miracle grow, and when I lifted the pot, it was so hot I needed pot holders to move it!  I was frying the roots!  It has recovered now, and it's really big with NO signs of FMV.  I rooted it from a UCD cutting (they all are infected), and I'm thinking that heat may have done the virus in!  I did get a back-up Panachee from a member because I feared I'd lost the other.  It shows heavy FMV, but not the one I fried!  I like them both and am just going to watch and see what happens.  The FMV free one is at the new property.  The back up is still here, and will be planted far from the FMV free one, but mites do travel.

I should take a picture, but it's down there, and we are here today.  It's got beautiful FMV free massive leaves!  And it was a start from a UCD cutting.

Suzi

don't think heat kills them. my trees stay out in 100+ weather during the summer. they all show FMV now and then. i heard cold might kill them. read few post indicating that members in north east have fewer sign of FMV in certain trees. FMV, if like other virus, might go dormant when in certain situations. 

Pete, this was serious heat!  Over 120 degrees.  Seriously, I had to get pot holders to move that container to part shade, and douse it with miracle grow.  It did survive beautifully, with no signs of FMV, but it suffered the heat!  I think the heat killed the FMV.

Suz

There are not many things I remember from high school biology but one thing is the electonmicroscopic image of a virus that sort of looked like the lunar lander from the apollo missions.  It was geometric and mechanical looking.  It is a very ancient form of life and is basically just the genetic code to take over another living cell.  It enters the cell and reprograms it for its own purposes.  I could be wrong but I thought man has never cured a virus to date.  We might be able to inhibit it and disrupt it but not destroy it.  That's why they are so dangerous.  Anyway perhaps panache is one of the varieties that can handle FMV and once you solved the heat stress problem the FMV is now more masked by the healthier tree.

Suzi, Heat regimes (thermotherapy) are reported to eliminate FMV in tissue culture of apical meristems. One of the reports has the temperature of the culture shifting from 94oF to 104oF (35oC & 40oC) during the light/dark periods every 24 hours for several weeks. So, you may have eliminated the FMD causing virus(es) from your tree after all. Cool! I will be interested to hear if the FMD free phenotype holds-up.

My recollection was similar but less specific to what DWD2 posted.  I also thought that fevers in our human bodies help in combating bacterial infections and viruses, not just to make us miserable.

When it gets big enough take a couple cuttings and grow them..you'll know with the first few new leaves if it has really been banished or just in hiding.

If heat is the solution,
why is FMV so prevalent in California ?

Possibly because almost all figs grown in California are grown in the ground, not in pots, so the soil doesn't get anywhere close to as hot as Suzi's potted plant.  In addition, most figs are not grown in hot desert conditions like Suzi is growing them.  Madera is probably the area with the biggest concentration of figs in the state ("fig heaven") and it's a little warmer there than my place, but still only getting perhaps 5-8 days over 100F each summer, on average.

Where I live the summer temps routinely get above 110.  I have trees that still show signs of FMV.  My trees are in the ground not in containers, so that may have something to do with it.  But if it was as easy as just heating a plant up to kill FMV then FMV would probably already be cured by now.  For most trees that have FMV the symptoms are most prevalent when the plant is young.  Many trees stop showing signs of FMV as they grow larger and mature.

I think Harvey could be right and soon that Panachee will be in-ground.  Although it rarely goes over 110 degrees at the new property, the roots underground are much cooler.  The roots in containers are so hot, here in the desert, I just keep them all under the canopy of the citrus or grapevines.  I learned my hard container lesson with that Panachee.

I will do as you suggest, and take cuttings when the tree gets big enough.  We will see if the cuttings show FMV.  It's one of my 1-5 gal trees that does not show any signs.  The only other FMV free one is an unknown that I got cuttings from a year ago.  It's FMV free so far, but I don't know if that one is a caprifig or a common fig.  Time will tell.

Suzi

Harvey is correct. There is a significant temperature differential between an in-ground plant's roots and the above ground portions. The plant's roots act as a reservoir for FMD viruses. Suzi's plant's roots in the pot sound as if they got to a much higher temperature than had they been in ground. The 1998 ActaHort paper by R. Gella et al describing thermotherapy of fig apical meristems references 2 papers from 1966 & 1978 that report the generation of "healthy fig plants" by the use of "traditional thermotherapy." It sounds as if Suzi is a traditionalist!