sometimes over fertilized soil can cause this to happen. how many are affected. if its just a few it could be due to a bit of stone that the roots encountered.

I think she lives next door to us! Leastways neighbour has pink jeans!

Thank you Owdboggy,you made me laugh.

Snap, made me giggle :-). It really does look like someone bending over. :-).

That 'soil' looks like rather dry clay to me, in which case root veg. will possibly bifurcate if they can't push straight down. Root veg., other than potatoes (which aren't actual root veg.) need a fine tilth that has not been manured that year.

I agree with all above. You can mix in some coarse sand to loosen it up. That's what I do for my beets, carrots & parsnips. The earthworms like it too. Clear out all underground rocks, roots, etc. Don't use chemical fertilizers. Opt for organic compost.