Melons seem to have rotted of in the pot

Not sure i might have watered to much some are fine but lost a few i noticed this evening while i been out in the garden pottering about. 

Cut worm where stem meets earth?, same thing with slugs?
Cukes, melon,pumpkin, all these sorts of things need watering from the bottom to stop the neck staying wet.......lost 3 cukes this year cos of this.......and i know i shouldn't do it. Somebody slap my wrist