Unpruned gives you more production by far. It would be impossible for a single-stem plant to match the production of multi-stems much less come close to that of an unpruned plant.

Literally hundreds of discussions about this question over on the Growing Tomatoes forum here.

Dave

No doubt you can get more tomatoes per plant if you do not prune it at all. But at the same time you will use almost three as much garden space. I grow mine in average 3 sq-ft per plant ( 21" by 21" or 18" by 24"). The widely recomended spacing for un pruned indet plant is 3ft by 3ft , that adds up to 9 sq-ft per plant. In the same(9 sq-ft) space I can plant 3 tomatoes and harvest more fruits than a single plant of the same variety. I have read some market growers use about the same spacing in their high tunnel. Because space is a valuable resource and you want to maximize your returns.

But in the end of the day, we do what we do and we have our reason, whether biased or based on logic.

You would not have 1 sq. foot each. The minimum recommendation for even a single stem plant is 2 sq. foot.

So the comparison would be 2 plants (not 4) vs. 1 plant and the 1 unpruned plant would still win the production challenge.

Again, as I suggested above, this is frequently discussed over on the Growing Tomatoes forum and many of those discussions include links to documented studies done on this very question rather than just personal opinions.

Please understand that much of the pruning done by its advocates is for aesthetic reasons only, for appearance, for garden eye-appeal, and for convenience for the gardener. It is not done for the benefit of the plant or for production,

They may live in a climate where sunscald of exposed fruit is not an issue. For you, and for us in the south, sunscald of exposed fruit is a very real problem. And given the predominance of some of the diseases we in hot climates have to deal with, the health of the plant so it can better resist those disease is vital. Drastically reduce the photosynthesis ability of the plant by pruning it aggressively can easily reduce its over-all health.

That is a lesson many of us have had to learn the hard way over many years.

A caged or staked or trellised plant grown in the proper spacing can still be lightly pruned as needed - any branches that touch the ground, any large leaflet branches that block access to the fruit can be trimmed back or removed, and late season sprouting suckers or bloom rellis can be pinched off, etc. But that in no way justifies radical pruning.

Dave