No doubt due to mutation of the genes for either pollen or the female stigma, but in the case of the hybrids probably due to incomplete manual pollination if male steriles were not used for seed production.

Carolyn

Over the years I have found a few and usually just rip them out and replace them once it is clear they won't set fruit despite ideal growing conditions.

Dave

I've seen many posts for stunted tomatoes, but all apply to the
plant. My plant is growing fine, its the fruit that has problems.

I am growing my tomatoes hydroponically indoors under LED lights in clay pellets. I am able to control grow room temps,
humidity, and nutrient temps within the recommended ranges.

I have four Kumato plants. Plenty of blooms, many set, I
have mature fruit on all of the plants.

My question concerns blooms that set to a BB size tomato
and grow no further. I have some that have been like this
for two months. I have other blooms that set and grow
fruit to the size of a large marble, then it stops.

On the four plants, I probably have 20 tomatoes like this. If
I could discover the cause of this problem I could greatly
increase my yields.

Conditions:
Using three part Flora nutrient in a flowering and fruiting formulation.

18 hours lights on, 6 hours off. Tomatoes do not need shortening days to produce flowers like some plants do.

Feeding six times per day for 15 minutes. Clay pellets, so the roots are getting a lot of O2.

Temperatures never get above 77 degrees F. Night temps drop to 62 -65 degrees F

Nutrient temps range from 65 - 70 degrees.

I maintain the nutrient PH between 5.8 - 6.3 and between
1100 - 1500 ppm.

I use Reverse Osmosis (RO) water and supplement with General Hydroponics CalMagic (Calcium and Magnesium).

Thanks for any ideas you might have.

Hope that helps,

Carolyn