Dirty rings on Carrots

[Lofty54]

Hi and good morning, can someone please help me, my carrots have got like a dirty rings around them and they go right through the carrot i would love to know if i can in the future do something to stop this,...Thank you ..... Lofty

[veggiechicken]

Sounds like carrot fly Lofty
Any damage inside the carrots?

[Two_Sheds]

dirty rings around them and they go right through the carrot

Yep, carrot root fly