why are tomatoes smaller at the end of harvest

[chastom]

why are tomatoes much smaller once the summer heat comes on ,is it just the end of the normal growing cycle or have they used up all there nutrients?

I have plenty setting but they go from being tennis ball size to quarter size after say 40 to45 days

we do have extreme heat here in tx 95 to 100+ is pretty common

[NarnianGarden]

Soil & nutrient issues?

[PaulF]

Farther north than Texas I think the length of daylight and sunshine and the angle of the sunlight has something to do with it. Perhaps we need to add fertilizer to add nutrients. Maybe the plants themselves are running out of the ability to produce large fruit. I feel like in the fall of my life I don't produce like I used to be able to.

[Sun City Linda]

Yep, I'm runnin' out of steam myself