Cabbage can become infected with a variety of illnesses. To some extent, all can be regulated, but in other circumstances, planting a resistant variety is the only option.
This article looks at nine common cabbage diseases and how to deal with them. Keep in mind that these methods vary greatly; what works in one situation may not work in another.
Rot in the black (Xanthomonas campestris)
Black rot, arguably the most serious cabbage disease, is transmitted to the soil by seed and spreads quickly under hot, rainy, and windy circumstances. It can live in lands and host plant stems for three to five years.
Yellow to light-brown patches forms at the leaf margins at first, followed by a network of black veins. Infected portions become brown and dry, creating a triangular lesion on the leaf margin, with one point pointing to the midrib.
As bacteria infiltrate the main veins and vascular system, the vascular tissue turns brown. Infected seedlings can die or become stunted.
Plant tolerant or resistant cultivars; utilize disease-free seed; practice crop rotation; avoid sprinkler irrigation and increase watering intervals; deep-plow all affected plant material.
Dissipation (Altenaria spp., Rhizoctonia solani, Pythium spp.)
Seedlings that have been infected with the virus wilt, turn purple and eventually die. Their lateral roots are frequently absent.
Control: Before planting, use treated seed and sterilize the seedbed; when symptoms emerge, remove contaminated plants.
This is often known as white mold, is a type of fungus that grows on the surface of (Sclerotinia sclerotiorum)
This illness thrives in cool, moist weather. A fungus causes it, and it can live in the soil for up to three years. The above-ground sections of the diseased plant may develop a white, cottony growth, while the tissue beneath the mold becomes mushy and watery.
Crop rotation; planting on ridges or raised beds; removing and destroying infected crop leftovers; proper water management focused on keeping the soil generally dry are all effective methods of control.
This is a type of grass that grows in (Plasmodiophora brassicae)
The spores of this illness can live in the soil for up to 20 years, and the disease is transmitted through the soil. It is particularly severe in soils with an acid or mild pH that is poorly drained or contains a lot of clay.
Stunted, withered, and purple leaves characterize infected plants. Large, elongated, or spherical swellings (‘clubs’) appear on the roots, which decay and form a moist, foul-smelling mess.
Crop rotation and sanitation are recommended, as well as growing transplants in fumigated beds and liming the soil.
Cabbage yellows due to Fusarium wilt (Fusarium oxysporum f. sp. conglutinans)
Summer is the peak season for Fusarium wilt, yet the fungus can live in the soil for years. Yellow foliage, usually on one side of the plant, is the first symptom to show. The leaves begin to sag, turn brown, and fall off too soon. Discoloration also occurs in the vascular (veinous) areas.
Plant resistant cultivars, grow cabbage in the winter, plant in disease-free soil, fumigate before planting and practice crop rotation and cleanliness.
Mildew (downy) (Peronospora parasitic)
In humid, cool conditions, downy mildew is frequent. The fungus thrives in the garbage and spreads through the air.
Infected leaves turn yellow around the ‘pepper’ patches as if lightly sprinkled with pepper. Large sections of the leaves are covered by lesions that have merged. During humid conditions, fine, fluffy white mold forms on the lesions on the leaf’s underside.
Control: – Irrigate the plants only between 3 p.m. and 10 a.m.; – Fungicide-treat seedlings; – Fumigate the seedbed; – Prepare and manage the seedbed well to ensure proper aeration and drying.
Legs in black (Phoma lingam)
When an infected seed germinates, blackleg can spread over the entire seedbed. The plant wilts and sores emerge on the stem and leaves when it becomes diseased.
These are white to light brown, with a purple-black edge and little black dots in the center.
Control: fungicide treatment of seedbeds; placement of seedbeds away from old production lands; destruction of seedbeds if leaf diseases are discovered; removal of all cabbage material left in seedbeds, as well as cruciferous weeds from production lands; removal of all trash after harvesting
Leaf spot caused by bacteria (Pseudomonas syringae PV. maculicola)
In cool, humid temperatures, the disease is more severe. Small, faint water-soaked regions appear on the undersides of leaves at first, and after a few days, they turn brownish to purplish-grey necrotic spots. They can generate enormous, oddly shaped areas if they unite together.
Control: – Chemical control; – Plant tolerant or resistant cultivars; – Use disease-free seed or seed treated with hot water; – Rotate crops; – Avoid sprinkling irrigation and increase irrigation intervals; – Control cruciferous weeds; – Deep-plough all diseased plant material
Leaf spot Alternaria (Alternaria spp.)
In chilly, rainy conditions, this sickness is common. Small, dark patches appear first, then quickly expand into huge circular lesions with a bull’s-eye pattern or target spot. Under wet conditions, the lesions appear dark brown. On older lesions, there is a brown, velvety, spore-bearing growth.
– Use disease-free or treated seed; – Remove or plow in plant waste; – Use chemical control.