oriental mustard under attack

[col mustard]

I'm growing oriental mustard for the first time and after 3 weeks of good cropping most plants now have at least 1 white maggot at the base of the stem finishing off the plants. Any one got experience of this and future remedy? I'm thinking cabbage root fly but not convinced as the maggots are above ground.

[burnie]

Sorry Colonel, never grown it, but welcome to the forum