[cloverley]

Why does some of my sweetcorn only have a few kernals, and don't look like the picture on the packets? Is it lack of water or food.

[tode]

Hello Cloverly, welcome to to the forum.
If you click on 'Search' and enter sweet corn' you should come up with quite a few discussions of corn and it's problems (and joys ! ).
Corn needs a lot of sun, warmth and water to grow properly, and they have to be packed quite tight together to ensure decent pollination. And then, with a bit of luck, you get delicious corn 
What sort of conditions did yours have ?

[DD.]

Just a few kernals certainly sounds like a pollination issue.

[chriscross1966]

Sounds like bad set....

two obvious causes... planting in a row rather than a block is one classic one, however getting unlucky with the weather can cause the male flowers (the tassels at the top) will be almost finished by the time the female flowers (the "silks" on the sides) become available..... I think some of my Blue Hopi popcorn has suffered from this problem this year, it's in a tight block but the male flowers were open a lot earlier than the females....

chrisc