Credits: Biovision-Infonet
Category Archives: Cabbage/Kale Diseases
Cottony rot
(Sclerotinia sclerotiorum) Credits:Biovision-Infonet Sclerotinia sclerotiorum is a fungus which can survive on infected tissues, in the soil, and on living plants. It causes white mold on cabbage, soybeans, green beans, sunflowers, canola, and peanuts. S. sclerotiorum affects young seedlings, mature plants, and fruit in the field or in storage. Cottony rot begins as tan, water-soaked, circular areas, which […]
Downy mildew on cabbage
(Peronospora parasitica) Credits:Biovision-Infonet Downy mildew is caused by a fungus which mainly attacks foliage. It is responsible for substantial losses in seedling production, especially during the cooler months. Young cabbage plants are more susceptible than older plants. The powdery white spores are the major means of dispersal of the fungus, especially once it is established […]
Ring spots
(Mycosphaerella brassicicola) Credits:Biovision-Infonet Ring spots are small, purple spots surrounded by a ring of water-soaked tissue on leaves which mature to brown spots with olive green borders 1-2 cm wide. The spots may develop numerous fruiting bodies which give them a black appearance or develop a concentric pattern. Heavily infected leaves may dry up and […]
Turnip mosaic virus (TuMV)
Credits:Biovision-Infonet The first symptoms to develop when Brassica seedlings are inoculated with TuMV are chlorotic spots on inoculated leaves, mottling followed by systemic vein clearing, mosaic and/or necrosis, leaf distortion and often stunting. What to do: Remove TuMV-infected plant debris and eradicate infected plants around fields as this can help to reduce virus inoculum and hence spread.
Damping-off diseases
(Pythium spp., Rhizoctonia solani, Fusarium spp.) Credits:Biovison-Infonet In crucifers, several fungi (e.g. Pythium spp., Rhizoctonia solani, Fusarium spp.) can cause damping-off diseases. Characteristic is wirestem of seedlings caused by Rhizoctonia solani in the seedbed, bottom rot and head rot in the field, and storage and root rot of horseradish, radish, rutabaga and turnip. Damping-off diseases are favoured by […]
Cauliflower Mosaic Virus (CaMV)
Credits:Biovision-Infonet It shows systemic symptoms such as a clearing along the leaf veins (vein clearing). This often is seen first at the base of a leaf. Later symptoms appear as dark green areas along veins (vein banding) and necrotic spotting of the leaf. Chinese cabbage is particularly susceptible to CaMV. In addition to vein clearing […]
Cercospora leaf spots
(Cercospora brassicicola) Credits:Biovision-Infonet Cercospora leaf spots is caused by the fungus Cercospora brassicicola. Leafspots vary in colour from pale green to white and generally are bordered by brown tissue. They may be circular or appear angular. Severely affected plants may become defoliated. This disease is not economically important in the East African region. What to do: […]
Bacterial soft rot
(Erwinia carotovora var. carotovora) Credits:Biovision-Infonet Bacterial soft rot is caused by Erwinia carotovora var. carotovora. It is quite common on Chinese cabbage in the field. On cabbage, turnip and rutabaga the disease may be found in the field, but is most severe during storage. On cabbage, an initial infection occurs on the outer petiole (leafstalk) which is in […]
Black leg
Credits:Biovision-Infonet It is serious cabbage disease caused by the fungus Leptosphaeria maculans (Phoma lingam). Symptoms of black leg usually appear as oval, sunken, light brown cankers, often with a black or purple margin, near the base of the stem. The canker enlarges until the stem is girdled and the plant wilts and dies. Severely infected plants are stunted. Infected plants […]