Question
I did search the FAQ's first, but found nothing that relates to my questions.  
Here goes:

I have a Brown Turkey plant I bought 5 years ago and put it in a 16" pot on
my patio in Redding, CT. with plenty 6+ hours of full sun. (zone 6)  

I take it into my cold cellar every winter (20-30 degrees)  It survives every
winter, and has no dead limbs.

I have pruned every Spring (obviously not NEARLY enough)  It has been
getting huge, with many main branches.  Two years ago I moved it into a
much larger pot- 36".  It responded by getting even bigger.  I am sure it is
root bound.  Here is it's fruiting history:

Year 2- small. Inedible figs. Mid Sept- leaves yellow and fall off.
Year 3- medium sized figs that never ripened.  Maybe 40 of them. Med Sept.
leaves yellow-fall off.
Year 5- Med- larger sized figs, maybe 60, about half of them the size of a
walnut.  Maybe 20 were edible, but not great.  It may be because I           
moved it to another spot. Same mid Sept yellowing, timed just about when
the figs are trying to ripen

Year 6- No fruit, not even small. Yellowing occurs now, a Month early.  The
first year with no figs, just the little bumps that might have been.

Now, I have been watering every other day.  Lightly fertilizing with fish
emulssion/seaweed mix, alternated with Cock a doodle doo, chicken poop
fertilizer every 3 weeks or so.  Leaves are always healthy.

My limited research tells me I need to do a bunch of things.  Prune heavily in
the spring.  And  replace the soil.  But I fear I need also to cut many of the
roots out of the root bound gigantic pot.  The tree weighs maybe 100-150
lbs at this point.

Is it too late to save this plant?  Should I give a number of trys to remedy the
situation, or toss it and get a small one next year and keep on top of it.  
Obviously I let it go, afraid to cut too much, and foolishly thought a giant pot
would end my problems.

Any help would be greatly appreciated.

Joe Chapura

Answer
In my research, there were twenty pages of material to answer your question. I will attempt to reduce it to a simple "how to get a fig on my tree."
Figs need as much sun as they can get. Up to eight full hours or more of direct light. Less sun means fewer fruit that won't ripen as quickly.
Prolonged hot dry weather can cause fruit to toughen, and fall prematurely. Supply adequate water and, move the tree to a cooler location with some shade. But move it back into the sun, when it cools down.
In July, trim the long shoots to stimulate branching, there by increasing the amount of fruit baring wood.
Actively growing trees can be damaged at 30 degrees, but dormant trees are hardy to 12-15 degrees.
Thirsty figs drop yellow leaves, and drought stress may express itself later in the year with lower fruit yields.
Prune your tree to shape it, and growth control. Bear in mind that since the fruit crop is produced on last year's wood, heavy pruning might reduce next year's harvest. Plan your pruning after the last frost and before the spring growth has started. Root pruning is beneficial, but not necessary. Figs like to be a little root bound. They seem to produce more fruit then.
Regular  fertilization is necessary for potted figs, but don't over do it. Too much nitrogen encourages green growth at the expense of fruit production, and can also cause improperly ripening fruit. Nitrogen can promote succulent growth late in the growing season, a condition or problem that makes plants susceptible to winter injury. Excessive nitrogen also results in light fruiting, fruit splitting, and souring.
If your tree occasionally drops mature fruit, it could be due to excessive nitrogen, or shade, winter injury,
drought, or poor soil drainage.
In conclusion, I would change how much nitrogen fertilizer you are using, keep the tree moist, but not wet, be careful how you prune, and give it more light.