Sweetcorn trouble

Dear All

This is my first year growing sweetcorn, we picked our first two yesterday, they are a supersweet variety called Butterscotch. The "pods" (if that's what they are called) were not completely full of kernels, there were lots of gaps where they hadn't formed kernels.

Has anyone got any ideas about what might make this happen? They are inter sown with runner beans and squashes.

Cheers

Thanks for your reply, yes they are planted in blocks, and I did lots of tassel shaking (!!), maybe I was just unlucky with these two and the other will be better........?

Unless it could be something else?