Clubroot is a soil-borne fungal disease. It affects the whole cabbage family and other vegetables kohlrabi, kale, radish, turnips, rutabaga, mustard greens, collard greens, arugula, bock choy and canola. Cool(14 to 25 C), wet (70% to 80 % poorly drained, acid to neutral soils flavor the disease. The pathogen can service in the soil for more than 8 to 10 years. Sometimes The clubroot pathogen can cause infection without any symptoms.
Club Root Of Cabbage Identification.
The symptoms will appear in the root region first that's why it's difficult to identify in the early stage.
Above the ground.
The older leaves turn yellow and die and the plant look stunt.
Abnormal wilting especially on warm days.
Death of the seedlings.
Older plants fail to produce the head.
Abnormal large primary, secondary and taproot.
Large clubs are formed on the roots on about 5 to 6 inches wide.
You can see the largest clubs just below the soil surface.
Infected seedlings will show systems after 3 weeks of infection.
The clubs are firm and lightly colored in the early stage.
In the lateral stage, it becomes black and decay.
The rotten smell from the infected area.
Club Root Of Cabbage spreading agent.
The disease spread from one region to another through soil's water and in soil on farm machinery and footwear. Agri machinery tillers and shovels can spread the disease if not cleaned properly. On a short distance, wind plays a significant role. On long-distance spreading occur in the roots of infected seedlings.
Club Root Of Cabbage Damage.
Symptoms will only be visible when they start affecting the above-ground part. By the time it's already one month past. Infected leaves are unable to absorb the food from the soil which leans to stunt height. Plants wilting during the hot days time and slightly recover at night. Root galls are often invaded by secondary organisms causing root decay and the death of the plants.
Control/Prevention for Club Root Of Cabbage.
Always use certified seeds for cabbage.
If the disease report in this soil then treats your soil with lime to raise the pH to 7.1-7.2. (500-1500 kg /h recommended)
Apply boron to the soil if the pH is less than 7.0 to 7.2 along with lime.
In the nursery
Proper clean of the seedbed and other tools.
Raise nursery plants in soil-less potting mix or pasteurised soil mixes.
Keep nursery areas at distance from fields where cabbage (and another brassica) crops are grown.
Improve field drainage; for example, make raised beds.
Plough fields deeply to bury debris infested with spores.
Carefully clean machinery, wheelbarrows, tools and footwear of soil to prevent the disease.
Do weeding in regular interval. Avoid over-irrigation to maintain the soil moisture.
Follow the crop rotation with non-hosting plants so that there will be some gap in between the host plants. Do not compost infected plants, and do not use manure from animals that have been fed debris remaining after harvest.