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Crucifers (Cabbage/Broccoli) pests, diseases and growing guide for Jamaica

What goes wrong with crucifers (cabbage/broccoli) in Jamaican conditions, how to recognise it early, and what the crop needs at each stage. 4 common problems covered.

Growing conditions at a glance

Plant family	Brassicaceae
Target soil pH	6 – 7.5
Seedling stage	Transplant to day 14
Vegetative stage	To day 60
Flowering stage	To day 60
Typical yield	3 lbs per plant
Harvest	Single harvest

Common crucifers (cabbage/broccoli) pests and diseases

Diamondback Moth

A major pest of cabbage and crucifers worldwide, highly resistant to many chemicals.

Signs to look for

Small 'window-pane' holes eaten from the underside of leaves
Tiny green wriggling caterpillars
Silken cocoons attached to leaves

What to do: Rotate chemical classes strictly to prevent resistance. Use Bt (Dipel) or Spinosad. Pheromone trapping.

Cabbage Looper

Large pale green caterpillars that move with a looping motion, consuming large amounts of foliage.

Signs to look for

Large, ragged holes in leaves
Dark green frass left on foliage
Looping caterpillars present

What to do: Apply Bt or Spinosad. Clean up crop debris post-harvest.

Clubroot

A devastating soil-borne disease of crucifers causing severely swollen, malformed roots.

Signs to look for

Massive swelling and distortion of roots
Wilting of plants during the heat of the day
Stunted growth and yellowing

What to do: Raise soil pH above 7.2 using agricultural lime. Practice strict 5-year crop rotation. Do not move infected soil.

Black Rot

A highly contagious bacterial disease of cabbage and crucifers.

Signs to look for

V-shaped yellow lesions starting from leaf edges
Blackening of veins within the lesions
Foul smell and stem rot

What to do: Use certified disease-free seed. Apply Copper-based bactericides (preventative only). Destroy infected debris.

Feeding crucifers (cabbage/broccoli) by growth stage

Stage	Nutrition	Why
Seedling	High Phosphorus	Promote root establishment for strong transplants.
Vegetative	High Nitrogen and Boron	Crucifers are heavy nitrogen feeders. Boron prevents hollow stems.
Flowering	Balanced NPK	Support head formation.
Fruiting	Balanced NPK	Support head formation.

Questions growers ask

What are the most common crucifers (cabbage/broccoli) pests and diseases in Jamaica?

The problems growers report most often are Diamondback Moth, Cabbage Looper, Clubroot, Black Rot. Each one is described above with the symptoms to look for and the recommended response.

What soil pH does crucifers (cabbage/broccoli) need?

Crucifers (Cabbage/Broccoli) performs best in soil with a pH between 6 and 7.5. Outside that range nutrients become progressively less available to the plant even when they are present in the soil.

How long does crucifers (cabbage/broccoli) take to grow?

Counting from transplant, the seedling stage runs to about day 14, vegetative growth to about day 60, and flowering to about day 60, after which the crop moves into fruiting or bulking.

Track it in the app

PlantArmor keeps your crucifers (cabbage/broccoli) spray records, input costs and harvest weights in one place, and works offline while you are out in the field. Free to use.

Open PlantArmor Get it on Google Play

Other crop guides

Pest descriptions and treatments above come from the same reference library the PlantArmor app uses in the field. Pesticide registrations and permitted uses change — always read the current product label and observe the stated rate, re-entry period and pre-harvest interval.