Clubroot is a fungal disease that primarily affects cabbage but also other cruciferous vegetables. The pathogen is difficult to combat because its spores survive in the soil. Which really helps.

Clubroot can not be treated; Prevention is therefore the only solution

Table of Contents

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  1. the essentials in brief
  2. What is clubroot?
  3. damage and symptoms
  4. Prevent clubroot
  5. Fight clubroot
  6. frequently asked Questions

    7. the essentials in brief

    • Clubroot is a fungal plant disease that primarily affects cabbage and other cruciferous vegetables.
    • The bulbous, thickened roots are characteristic, and affected plants also wilt.
    • The fungus lives in the soil, which is why it is imperative to observe a break of three to five years after growing cabbage.
    • There are no direct ways to combat it, only preventive measures.

    What is clubroot?

    Clubroot is a fungal disease commonly found in cruciferous vegetables. The cause is a slime mold with the scientific name Plasmodiophora brassicae, which lives in the soil and forms permanent spores there. Once infested, these can last up to 20 years. The fungus penetrates through the roots and primarily allows the subterranean parts of the plant to proliferate uncontrollably. The resulting bulbous thickenings in turn damage the plant's pathways and ensure that the plant is no longer adequately supplied with water and nutrients. Affected plants wither and often die.

    Which plants are particularly affected?

    All types of cabbage are particularly frequently affected by clubroot, but especially kohlrabi and Brussels sprouts. Broccoli, cauliflower, red and white cabbage, savoy cabbage, kale or Chinese cabbage are also affected. Not only cabbage, but also other vegetables and ornamental plants are at risk, provided they belong to the cruciferous family. These include, for example:

    • canola
    • mustard
    • Rocket, garlic rocket
    • cress
    • radish
    • gold lacquer
    • bittercress
    • silver leaf

    tips

    If "weeds" such as shepherd's purse, meadowfoam or hunger flowers appear in the vegetable or ornamental bed, pluck them out as quickly as possible. They also belong to the cruciferous family and can carry the infection into the bed - especially the shepherd's purse is susceptible to clubroot.

    Identify clubroot - damage and symptoms

    Clubroot is best recognized by its thickened roots

    The clubroot pathogen feels particularly comfortable in moist and warm soil, especially if the pH value is also in the acidic range. In this environment, the slime mold finds the best living conditions and multiplies profusely. Its extremely hard-wearing spores survive in the soil for up to 20 years - which is why the disease, once it has occurred, can break out again many years later.

    You can recognize an infection with Plasmodiophora brassicae by these signs:

    • poor growth of the affected cruciferous vegetable
    • wilting, yellowing leaves
    • drooping leaves on warm days
    • tuberous roots

    If you suspect clubroot, dig up one of the supposedly diseased plants and check its roots: These are typically tuberous to cylindrical and thickened.

    digression

    Confused with cabbage weevil and other pests

    Clubroot doesn't always have to be behind bulbous roots and wilting plant parts, sometimes it's just a pest like the larvae of the cabbage weevil. Examine the diseased plant for the presence of larvae or adults and for damage caused by feeding. Cut the thickened roots: if they are hollow inside, cabbage-eating larvae are probably at work.

    Can you prevent clubroot?

    Cabbage must not be too moist and must be adequately supplied with nutrients

    "Once clubroot is in the ground, the pathogen is very difficult to combat."

    Since clubroot is very difficult to get rid of once it has broken out, you must focus primarily on effective prevention. This includes two main strategies:

    • Optimize location and soil
    • Observe crop rotation

    Regarding the first point, it should be said that clubroot mainly spreads on moist soil. So ensure good drainage so that the soil always dries well and is not permanently wet. When growing cabbage plants, you also prefer well-drained, sandy soil, whereby you must not forget to fertilize regularly - cabbage is a heavy feeder and needs a lot of nutrients.

    Also check the pH value of the soil with a simple strip test and raise it by liming if necessary - if possible in the alkaline range. Liming not only helps prevent clubroot, but also provides the vegetable plants with an important nutrient. Garden lime has proven itself for this purpose, but also bedrock dust.

    When it comes to crop rotation, remember that a bed where you have cabbage and other cruciferous vegetables may not be cultivated with any other cabbage or cruciferous vegetables for the next three to five years. If this is not possible, for example due to a lack of space, first apply green manure after the harvest (no rape or mustard!) and then apply plenty of humus - for example in the form of mature compost. Both help to keep the amount of fungal spores as low as possible. Plants infested with clubroot and crop residues should never be placed in the compost heap, but always in the residual waste.

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    Are there resistant varieties of cabbage?

    The following cabbage varieties are currently listed as resistant to clubroot: 'Clapton F1' (cauliflower), 'Kilaton F1' and 'Kikaxy F1' (both white cabbage), 'Crispus' (Brussels sprouts) as well as 'Autumn Fun F1' and 'Orient Surprise F1' (both Chinese cabbage).

    Combat clubroot - These funds will help

    A direct control of clubroot is not possible. However, you should immediately pull infested plants out of the ground together with their roots and dispose of them in the household waste.

    frequently asked Questions

    Is it still possible to eat cabbage infected with clubroot?

    Yes, in principle this is possible - but only on the parts of the plant that have not yet been affected by the fungus. Cut away any affected parts generously and cook the leftover cabbage well.

    Aren't there any chemical remedies that help against clubroot?

    No, there are currently no plant protection products that are effective against clubroot and approved for home or hobby gardens. Also sulphur, copper or broad spectrum fungicides have no effect.

    tips

    If clubroot has ever appeared on a bed, you should not plant strawberries there. Although these are not susceptible to the diseases themselves, they can keep the fungus alive and thus continue to multiply.

Category:

Vegetable garden