Mould on me tommy?

Evening all Bob flemming here,I noticed today i had a blacky/browny almost mouldy large spot on the underside of one of my tomatoes ,any ideas what this could be? I only give them a small watering everyday so don't think it's that.They are still green but just starting to turn,any replies greatfully recieved.Bob:thumb:

 

Hello Bob.
I think it`s Blossom End Rot.It`s usually down to the soil drying out especially when toms are grown in bags.You must give loads of water when the fruit is swelling.There`s not much to be done except to just cut that part away on eating.

 

I agree Bob, bottom end rot. Irregular/not enough water. Once the plants are burdoned with swelling fruit, they develop a thirst like there's no tomorrow. Another symptom is fruit splitting as it ripens. Both are common problems with tomato growing.