Well, that is a good question.

I know one thing that tomato plant is very greedy plant. It will not give up until it is dead, Either killed by the gardener (sometimes) or diseases (often) and the killer frost(more often). So based on this characteristic, my personal answer to your question is : WHEN THE PLANT IS DEAD.

seyson . You must have misunderstood ! I'm asking about the individual fruit " NOT THE PLANT "

This post was edited by Marshallkey on Wed, Aug 21, 13 at 7:49

Lots and lots of variables but basically a fruit will "quit growing" in size depending on where on the plant it is located and the plant circulatory system it has available to use. So a fruit near the top growing on a secondary stem will be smaller in size than one growing at the same height but on the primary stem or ones near the bottom of the plant.

Just like the human body where the core size is bigger than the extremities and gets worse as we age. :-)

Some limited water weight could still be gained by the fruit as it ages but at least they don't have to worry about developing fat deposits like we do.

Dave

Agree with Dave on his answer.

Look at any plant's fruits and you'll see a range of sizes with ripe fruits for a single variety.

Internal distribution of water and nutrients can vary, as he mentioned, and that in turn can be variety related and also impacted by weather conditions.

There's also a bit of biological diversity going on which is why the experts say it's best when saving seeds to save seeds from fruits of different sizes of a single variety.

Just as there is biological diversity with tomatoes, in general, there's also biological diversity for single varieties and that inherent biological diversity is important in terms of variety preservation.

Carolyn

seysonn, your answer made me smile. This is exactly what I observed. I always grow the indeterminate kinds and they keep growing and growing and growing...... putting out flowers out in November, if weather is on a warmer side....