Identifying And Treating Common Cabbage Pest & Diseases

By Author: Prashant Manne
Total Articles: 7
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Introduced to India by migrants, cabbage is a crop that has adapted well to the Indian soil and climate. Also known as brassica oleracea, it grows well in fertile soil and in partial shade or sun. It is available in a variety of green shades, as well as in purple or red. Green cabbage and bok choy have a comparatively smooth lead while napa cabbage and savoy leaves are crinkly.

These cruciferous vegetables are grown for their leaves. They are cool-season crops and can tolerate light freezes. Many farmers face challenges due to the moist conditions that can damage the cabbage crops.

This article aims to inform readers of the pests or diseases that affect your cabbage crop, how to spot these, and also effective control and prevention methods.

**Insects Affecting the Cabbage Crop**

Aphids, worms, moths, and slugs are the most common pests that attack a cabbage plant. Below are the symptoms of the insects and how to prevent and control them.

Aphids

This pest affects crucifers in the cold season. Both the nymphs and adults suck sap from the plant causing ...
... loss of vigour. A sooty mould develops on excreted honeydew and leads to a reduction of photosynthesis.

Symptoms: Aphids can be spotted by misshapen or yellow leaves; distorted flowers/ fruit; sticky ‘honeydew’ (excrement of the incest); and sooty black mould.

Control / Prevention:

• Growing companion plants

• Knocking off the insects with water spray

• Applying an insecticide soap

• Putting banana or orange peels around the plants

• Wiping leaves with a 1 to 2 percent solution of dish soap and watering every 2 to 3 days for 2 weeks

• Adding native plants to invite beneficial insects.

**Cabbage Loopers**

The caterpillar is velvety green and is called a looper as it arches its back into a loop when it crawls.
Symptoms: The signs of loopers can be seen through large, ragged holes in leaves from larval feeding; defoliation; stunted or bored heads; excrement.

Control / Prevention:

• Removal through handpicking

• Adding native plants to attract beneficial insects

• Spraying larvae with insecticidal soap or bacillus thuringiensis (Bt)

• Using row covers

• Removing plant debris regularly

**Cabbage Root Maggots**

These flies are delicate, hump-backed and gray-brown flies that are about 5-7 mm long.

Symptoms: The symptoms of root maggots are seen through wilted or stunted plants; off-colour leaves and larvae feeding on roots.

Control / Prevention:

• Monitoring adult maggots with yellow sticky tapes

• Using row covers

• Using collars around seedling stems

• Destroying crop residue

• Till the soil in fall

• Crop rotation

**Cabbage Worms**

The cabbage worms are velvety green larvae with a few faint yellow stripes. There are many insecticides for cabbage worms in India that help in the control of these pests.

Symptoms: The leaves have large ragged holes or are skeletonized; the heads are bored; dark green excrement; yellowish eggs laid singly on leaf undersides.

Control / Prevention:

• Handpicking the pests

• Using row covers

• Adding native plants to invite beneficial insects

• Growing companion plants like thyme

• Spraying with Bt

**Flea beetles**

Flea beetles are small, shiny beetles with large rear legs that allow them to jump like fleas when threatened.

Symptoms: Numerous tiny holes in leaves

Control / Prevention:

• Using row covers

• Mulching the soil heavily

• Adding native plants with the crop to invite beneficial insects

**Slugs / Snails**

These are found most often in temperate or humid climates. They are likely to affect the crop during rainy seasons.

Symptoms: These are symptomized by irregular holes in leaves; gouged fruit; slimy secretion on the plants/ soil and ‘disappearance’ of seedlings.

Control / Prevention:

• Handpicking the slugs or snails

• Using copper plant collars

• Avoiding overhead watering

• Laying boards on soil in evenings and disposing of any ‘hiding’ insects in the morning in hot, soapy water

• Placing shallow containers filled with ½ inch of beer or with water with sugar/ molasses/ flour or cornmeal and yeast. This will lure the snails or slugs to a drunken death.

• Applying a 1-inch-wide strip of food-grade diatomaceous earth as a barrier

**Stinkbugs**

The harlequin cabbage bug is a species of incest from the stinkbug family that sucks sap and chlorophyll from crops causing them to wilt and die.

Symptoms: Stinkbugs leave yellow/ white blotches on leaves; scarred, dimpled, or distorted fruits or pods; shrivelled seeds; the eggs are often key-shape in clusters on the undersides of leaves.

Control / Prevention:

• Destroying crop residue

• Handpicking the bugs (the bugs emit odor so make sure to wear gloves)

• Spraying the nymphs with insecticidal soap

• Using row covers

• Weeding

• Tilling the soil in fall/autumn

**Thrips**

Thrips are tiny insects that are as fat as a sewing needle. Their colours can be anywhere from yellow to brown or black.

Symptoms: The leaves, especially in the folds near the base have white patches or silver streaks; brown leaf tips; blistering or bronzing on cabbage leaves; curling or scarring of leaves and distorted or stunned bulbs/ heads.

Control / Prevention:

• Choosing resistant varieties

• Removing plant debris

• Adding native plants to invite beneficial insects

• Using row covers

• Using straw mulch

• Monitoring adults with yellow or white sticky traps

• Using sprinklers or other types of overhead watering systems.

**Fungi Affecting the Cabbage Crop**

The cabbage crop is affected by various fungi like black rot, clubroot, downy mildew and white mould. Cabbage crop fungicide by Jivagro helps in the successful control and prevention of these fungi. Here is how to spot these common diseases and ways to control/prevent them:


**Blackrot**

Symptoms: First appears as yellow, V-shaped areas near the leaf margins that eventually brown and spread towards the center; veins turn brown and eventually turn black.

Control / Prevention:

• Destroying the infected plants

• Choosing resistant varieties before planting

• Providing a god drainage system to plants

• Removing any plant debris

• Rotation of crops

**Clubroot**

Symptoms: It is seen through stunting and yellowing of plants; yellowing of leaves; roots appear swollen and distorted.

Control / Prevention:

• Destroying infected plants

• Solarizing the soil

• Maintaining a soil pH of around 7.2

• Disinfecting the plantation tools

• Crop rotation

**Downy mildew**

Symptoms: It can be spotted by small purplish-brown spots under the surface of leaves; yellow, angular spots on the upper surface of the leaves; white/purple/gray cotton-like growth on the underside of the leaves; distorted leaves or corn tassels; defoliation.

Control / Prevention:

• Removing plant debris

• Choosing resistant varieties while planting

• Ensuring good circulation of air

• Avoiding overhead watering of plants

**White mold**

Symptoms: White mold is symptomized by pale gray and ‘water-soaked’ areas on stems, leaves, and other plant parts that enlarge and develop white, cottony growth with black particles; bleached areas on the leaves; rotting of the crown or fruit and collapsing of plants.

Control / Prevention:

• Destroying any infected plants

• Ensuring good air circulation

• Regularly weeding

• Destroying any crop residue

• Crop rotation every 5 years

• Watering in the mornings

Cabbage can fall victim to an array of diseases from the above. These infections can range in severity from unsightly to fatal. Good gardening practices like keeping weeds and pests at bay, regularly sanitizing your equipment and preventing moisture build-up can help prevent outbreaks.