Neither clubroot nor Rhizoctonia. Likely to be cabbage maggot. Found a good image of damage on canola root at http://www.canola-council.org/gallery/855/pests_insects.aspx?photo=12 So I guess you'll be studying up what to do next year to avoid. For one, you need to plant in a different place. Most likely, local agricultural/garden people in your region have info for you. In the meantime, take a look at what the University of California says at http://www.ipm.ucdavis.edu/PMG/r108300111.html Good luck. Here is a link that might be useful: damage on canola root

If you're positive there are no caterpillars then you should go out at night and check for slugs. The little bugs flying around sound like fungus gnats caused from having the mix in the pot too wet or from having a dirt/compost component in the potting mix. Their larva can do damage to the roots if they are in high enough concentrations but they don't damage leaves. What size pot is? What type of mix is it planted in? How much are you watering? And how much sun does the plant get? Rodney

hard to defeat the cabbage maggot, but if you look carefully for the distinctive pupa in the soil in that area, you might be able to eliminate a lot of'em - then if you plant cole crops again, put the collar around the plants that link explains - I don't think they'll affect leeks, at least I've never had a problem w/ leeks, and I grow lots of'em every year - also a floating row cover is helpful w/ that pesky white cabbage moth which is everywhere up here Bill

Many beetles are actually beneficial - the Calosoma Beetle being the best-known to me. Large and black with iridescent green and blue coloring, these predators will climb trees in search of their favorite food: caterpillars, particularly tent and gypsy moth caterpillars. (This info confirmed by Clemson Univ.) From an orgnization in the UK, I read that "...the vast majority of ground beetles are extremely beneficial and important predators which help in the natural control of many garden and crop pests, such as grasshoppers, crickets, termites, aphids, plant bugs, leaf beetles, weevils, wireworms, chafer grubs, butterfly and moth caterpillars, sawfly caterpillars, crane flies (leatherjackets), fruit flies, gall midges, many other fly pests, as well as slugs and snails." Therefore, I make no special attempt to rid my yard of beetle grubs, but do watch for harmful adults and eliminate them. Diane