[Salty]

Afternoon; In the last week my sweetcorn has developed sideshoots low down on the stem. I have never seen this before, is it normal?
I have removed the sideshoots with a sharp knife but after only three days new sideshoots had developed on three or four of the plants again.
The side shoots had developed on almost all of my first sowing of sweetcorn. Approx 20 plants. Sweetcorn is Swift F1.

[Subversive_plot]

Not seeing the appearance of these side shoots, are you sure you are not cutting off what could have become ears of corn?  The ears will develop on the side of the stem.  That tends to be in the middle of the main stem:

The shoots could be tillers.  Removing them is not beneficial, but might not be harmful.  See: https://www.agry.purdue.edu/ext/corn/news/articles.03/Tillers-0623.html

[JayG]

I've grown many varieties over the years, including Swift, and some of the plants always develop tiller shoots from the base. In theory, you could get additional cobs from the tillers, but even in sunny Sheffield the summers aren't long enough for that happen. 

The plants without tillers seem to crop the same as those with them, so I just leave them to it.

[Salty]

Thanks for the replies.
The sideshoots are growing from the base of the stem so I dont believe they would have developed into ears of corn.

[Yorkie]

I tend to just leave them be too (only because I'm too lazy to make any decisions about them  )

[pdblake]

I get these most years and just ignore them.

[mumofstig]

Thanks for the replies.
The sideshoots are growing from the base of the stem so I dont believe they would have developed into ears of corn.

I leave them alone, and sometimes they do   

[cc]

I don't know what you are talking about!

[Subversive_plot]

I don't know what you are talking about!

Google "corn tiller", view images.

For you convenience, I included a link at the bottom of my June 26 post.

[AndyRVTR]

From what ive read over the years, some gardeners remove the suckers believing that the sideshoots reduce sweet corn yields by diverting energy from the main stalk and developing ear. Apparently, they develop on plants that are spaced too far apart & giving too much nitrogen and too much water will also promote sucker formation.
In the fields, farmers don't cut off the suckers, they just let them get on with it.