Monday, April 24

The root of the problem

Parts of our plot are affected by club root that affects members of the brassica or crucifer family. It is extremely difficult if not impossible to control. The disease thought to be related to slime moulds and has plant, fungal and animal characteristics. How scary a thought is that?

Club root affects all members of the brassica family including weed's such as shepherd's purse and crops such as oil seed rape. It is spread by infected plant material coming into contact with soil and releasing spores. The spores produce things called zoospores that can swim short distance through moist soil in search of brassica root hairs and so the infection begins resulting in the root of the plant swelling.
The  roots can then no longer support the plant and so it cannot take up moisture and nutrients and so becomes weak and often dies.

Once infected the spores can lurk in the soil for twenty years or so waiting for a suitable host plant. Most gardeners would find it impossible to avoid planting any sort of brassica into a patch of land for twenty years and when if they did self sown susceptible weeds playing host.

We know that our soil has been infected for years but in our early gardening days we used a dip on young plant roots that gave some protection. Unfortunately this was one of the gardening products that became unavailable and now there is little that can be done to treat cub root infested soil. Adding lime can help as club root doesn't like alkaline soil nor does it like well drained soil but as our soil is heavy clay this isn't something we can easily control.

Our option is to raise club root resistant varieties of brassicas. There are more varieties being developed but to date there doesn't appear to be a club root resistant variety of sprouting broccoli.

We also buy brassica plants early and sometimes late in the season. These are from well respected sources and should be club root free but are not varieties that are resistant to the infection. We've tried to plant these in beds where club root hasn't appeared to be an issue in the past but the disease is quite difficult to prevent from spreading. This year we are trying a different tactic and growing the bought in plants to a larger size before planting out.
The hope is that this will give them more of a chance against the disease.

Last week we did have one pleasant treat and cut a rather splendid cauliflower from a bed in which the rest of the brassicas failed to thrive. 
This - Aalsmeer -isn't advertised as a club root resistant variety so were we lucky of does the variety have some level of natural resistance? The roots didn't seem affected by the disease.
There are one or two more plants that may produce heads as they look to be growing strongly.
We do try in our battle against club root but I do wonder whether the battle is weighted against us succeeding. There seems to be so many ways that club root spores can affect soil and, other than growing plants under laboratory conditions, very little we can do to prevent it's spread.

As well as the cauliflower we also harvested a few leeks.
It's an amazing thought that next year the seedlings sitting in our greenhouse will be gracing our dinner plates.
To end a plea - if there are any plant breeders out there can you please develop a club root resistant variety of sprouting broccoli?

I am linking to harvest Monday hosted on Dave's blog Our Happy Acres




30 comments:

  1. That sounds like a pretty dreadful disease. I'm sorry you're struggling with that. Hopefully the breeders will heed that call!

    ReplyDelete
    Replies
    1. I would like to think so, Sue after all it can't be much more difficult than breeding a club root resistant cauliflower can it?

      Delete
  2. I don't guess I've ever seen club root before, and hopefully I won't see it here. It's too bad there aren't more resistant varieties out there.

    ReplyDelete
    Replies
    1. I hope you never have to see it in real life, Dave.

      Delete
  3. It is so frustrating to have such nasty diseases in the garden. Fortunately, I've not seen club root in my garden. Good luck on finding more resistant brassica varieties. That cauliflower looks like a keeper! The worst scourge in my garden the past few years is garlic rust, I can no longer grow garlic or leeks because the rust ruins it and so far as I know there are no rust resistant varieties of garlic or leeks and no effective organic treatments. So I'll add rust resistant garlic to that wish list!

    ReplyDelete
    Replies
    1. Let's hope the breeders are listening or maybe even reading, Michelle

      Delete
  4. I did not know about such serious problem, Sue. And I think I've never seen this club root disease. If I have in my garden fungi diseases I often use any chemical treatment.

    ReplyDelete
    Replies
    1. There is no treatment for club route available here, Nadezda. At least there is none available for the amateur gardener I don't know about the professional grower.

      Delete
  5. I've known about club root but never seen what it looks like before. It probably doesn't help on allotments where not everyone knows about it and therefore can help to try to stop to spread the disease. Have your committee tried to inform people? A really informative post Susan, thanks.

    ReplyDelete
    Replies
    1. We don't have an allotment committee, Julireanne however I think our problem has been in the soil for many years even before we took on the plot. Probably perpetuated by weeds belonging to the brassica family..

      Delete
  6. I've not seen club root before either - I suppose that may be one benefits of our alkaline soil. Have you considered or tried growing a few brassicas, such as the sprouting broccoli, in your home garden instead of at the allotment?

    ReplyDelete
    Replies
    1. We don't have anywhere in the garden for growing vegetables, Margaret other than a few salads in a small raised bed. We have wondered though about planting one or two broccoli plants in large parts.

      Delete
  7. It's a terrible disease isn't it? I don't have that problem....yet. But brassicas hate my sandy soil and don't do terribly well. That is a mighty fine cauli! Wishing you luck with those new plants. I always find it odd when planting leeks, I have seedlings sprouting and mature plants in the veggie patch.xxx

    ReplyDelete
    Replies
    1. Your soil will be quite free dtraining, Dina and club root disease prefers moist soil. It's a pity that the brassicas don't like it either.

      Delete
  8. Great article, and good pics, I've never seen it before... luckily. I'd noticed that a few people on our site buy their brassica plants, maybe that's why.

    ReplyDelete
    Replies
    1. Buying brassica plants doesn't cut down the chance of having club root, Dicky. It can actually increase the chances if you buy plants from a source that isn't careful about producing disease free plants.

      Delete
  9. I guess the PSB is in the ground for so long that it is bound to succumb. Aside from the measures you have described rotation is supposed to be the best preventative measure, and I know you already do that. It reminds me of the white rot onion situation we have. In a wet year we will get white rot (smutty nose) on our onions and they will either rot on the spot or not store well. The books say not to try to grow onions on the same patch for 8-20 years!!! Disregarding this defeatism (but rotating and adding sand for drainage) we still get a reasonable crop - in dry years. I have yet to decide whether weed suppressant fabric helps or hinders this condition.

    ReplyDelete
    Replies
    1. It's just a shame that they took the dip that we used to use of fthe market, Mal it was really quite effective. I think it was something to do with the fact that it would be too expensive for the powder to have to undergo all the testing required by the EEC. I'm guessing that commercial growers have something that they can use. Of course it doesn't help when oil seed rape escapes from the fields and seeds everywhere.

      Delete
  10. What a pain! It is always something. I am thankful to say I've never heard of it and hope I never do!

    ReplyDelete
    Replies
    1. You are right, Bonnie and for brassicas there seems to be plenty of diseases pests and pitfalls waiting to catch you out.

      Delete
  11. It sound scary Sue! I have seen some of my vegetables root swelling and the plant died soon after. Mostly cucumber. Not sure what disease is that....

    ReplyDelete
    Replies
    1. I wonder if you actually have a club root problem in your part of the world, Malar. I wonder what it is that happens to your cucumbers though.

      Delete
  12. The brassica family is so large, so it makes sense how certain weeds can keep perpetuating the problem. The seedlings you've potted up look nice and healthy, and I'm always impressed with the size of your leeks.

    That's disappointing that your root dip disappeared off the market, club root is such a difficult disease.

    ReplyDelete
    Replies
    1. It is a shame when something that worked was taken from the market, Phuong. I think the rules on testing made it uneconomical.

      Delete
  13. I can identify with your frustrations over club root... we seem to have acquired it in one bed last year, goodness knows where from! I am trying resistant varieties this year: Simply Seeds stock a calabrese called Monclano which at least should provide some summer spears/heads I hope!

    ReplyDelete
    Replies
    1. Quite a few seed companies stock Monclano, Kathy. It's one of the varieties that we have grown successfully.

      Delete
  14. What a shame Sue! It is easy to get disheartened by things like this as they are such difficult problems to solve. On the positive side, the caulk and leeks look fantastic ! Gardening is so unpredictable !

    ReplyDelete
    Replies
    1. Gardening is full of such challenges, Janet. It's character building.

      Delete
  15. I hope growing your brassicas on in pots works for you Sue. I hadn't realised that club root could spread so easily. I'm growing leeks for the first time this year (starting in modules) and your last photo has given me an idea of how tall they should be before I plant them out. Do you leave yours until after the last frosts before planting out?

    ReplyDelete
    Replies
    1. You may find that you get a better idea of size in this post, Caro. We don't purposely wait 'til after frost but it tends to be then that the plantlets are at the right size.

      Delete

Thank you for visiting and leaving a comment - it is great to hear from you and know that there are people out there actually reading what I write! Come back soon.
(By the way any comments just to promote a commercial site, or any comments not directly linked to the theme of my blog, will be deleted)
I am getting quite a lot of spam. It isnot published and is just deleted. I have stopped sifting through it and just delete any that ends up in my spam folder in one go so I am sorry if one of your messages is deleted accidentally.
Comments to posts over five days old are all moderated.