I've been reading through the threads about FMV and trying to look at other online resources. This is a 2 year old Brown Turkey. I just double-checked now: it isn't root bound, I had potted up a few months ago. I gave it a regular dose (label) of slow release fertilizer. The leaves shouldn't be sunburned, because I acclimated it the same as other trees that aren't sunburned. Any advice would be great. From what I've seen in pictures, this seems more of a "burn" of some sort. The somewhat stunted growth of the tree would suggest root bound, but in this new pot, it has at least 3 inches of open space all around. Is that enough for potting up? Does this need to be root pruned?
 
 
 
 

Oh no, poor looking tree. :-(

I am not an expert, but could it be more a sort of fig rust?

i'll say FMV.

Sometimes figs put out weird leaves.
Did you just bring it into the sun ?

In terms of sun, no - it's been acclimated over the last few months. Most the of the leaves on the tree are misshapen. It was brought into sun the same way/length of time as my other figs, and none have leaves like this.

If it is FMV, is that something you just live with and leave as is? Just let 'er grow? Prune the affected leaves/branches?

It looks a little stressed for some unknown reason.  Same mix as your other plants?  Could the mix have gone sour?
If you have good strong roots than that may not be the case.
If it were mine I might give it a little late afternoon shade(like 20% shade cloth.)
Keep it well hydrated (never let it go to wilt level but not wet).
I would keep fertilizer at 1/2 recommended level until I saw some improvement.
I would not prune leaves until lots of new healthy leaves are growing.
The miss-shaped leaves can still provide energy to the plant for new growth.
Make sure you have no bugs.
slow and steady will often bring plants around so be patient and don't try to rush to make it look good.

Arne,
IMO, It looks like nutrient deficiency and or a pH problem.
Does your fertilizer have micronutrients (many do not) and do you have a source of calcium in your potting mix?
Deformed new leaves are sometimes a symptom of Calcium deficiency.
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If it was severely root bound before you potted it up you may need to root prune.  I would give it 1/2 cup of Epsom salt and water real well, put in a shady/filtered sunlight place and let it alone.  It will be okay, leave it alone.

I would not root prune now!  Its very stressful, only root prune when dormant. 

However, I doubt that is your problem.  I agree either FMV or nutrient deficient.  Do you add limestone to your mix?  In addition to raising pH it adds calcium.  Micronutrients are needed as well.  Ironite has a lot of them, not sure if it completes all the needs assuming the major nutrients are satisfied though.  Some have seen that micronutrients and fertilizer helps with FMV symptoms as well.