Dear Penny, 

Thank you for contacting us about turnip pests. The damage you describe (furrows, tracks) are not likely caused by club root which usually creates irregular growth (see attached photo). Wire worms are a possibility, as are root maggots. 

https://pnwhandbooks.org/insect/vegetable/vegetable-pests/common-vegetable/vegetable-crop-cabbage-maggot

https://pnwhandbooks.org/insect/vegetable/vegetable-pests/common-vegetable/vegetable-crop-wireworm

I suggest you take a sample to the Marion County Extension office where they can inspect the damage. The garden help desk is generally open Mondays thru Fridays from 9 am to 1 pm.
1320 Capitol St NE #110, Salem, OR 97301
Garden Help Desk: 503.373.3770

I hope this is helpful information. Please write again whenever you have a gardening question.

Thank you!
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