Pests and diseases of bunching vegetables

Bunching vegetables – an overview:

This page provides an overview of the key pests and diseases of bunching vegetables in Australia. The related tools provided at the end of the page can be used by growers and crop consultants to assist in the identification of insect pests, mites, diseases, beneficials, and disorders. They include photographs and detailed information about specific pests. For unknown pests, it is important to have an expert identify them so that they can be managed appropriately.

Bunching vegetables include the Asian leafy brassicas such as buk choy/pak choy; beet; Dutch carrots; parsley; kangkong; radish; spinach (also known as English spinach); and spring onions. Bunching vegetables are affected by the pests that commonly cause damage to other vegetable crops from their family of vegetables.

Key pests of Bunching Vegetables:


Insect pests


Buk Choy/Pak Choy/Asian leafy brassicas Diamondback moth; Catepillars; Aphids; Onion thrips; Rutherglen bug; Brassica flea beetle; Silverleaf whitefly. White leaf spots; White blister; Downy mildew; Alternaria leaf spots; Phoma leaf spot; Black leg; Damping-off; Clubroot; Root rot; Mosaic virus; Bacterial leaf spots; Bacterial soft rot; Black rot.
Beet Beet webworm; Aphids; Vegetable weevil; Western flower thrips; Whitefly. Damping-off; White blister; Cercospora leaf spot; Downy mildew; Phoma leaf spot; Powdery mildew; Black root rot; Root-knot nematodes; Bacterial leaf spot; Bacterial blight.
Dutch carrots Cutworms; Rutherglen bug. Alternaria leaf blight; Root rot.
Spinach (English) Aphids; Caterpillars; Leafhoppers; Thrips. Downy mildew; Leaf spots; Root rot; Wilt; Mosaic virus; Nematodes.
Radish Aphids; Diamondback moth. White blister (rust); Clubroot; Black rot.
Parsley Thrips; Cutworms; Wireworms; Looper caterpillars. Alternaria leaf blight; Botrytis blight (Grey mould); Downy mildew; Powdery mildew; Fusarium root rot; Rhizoctonia crown and collar rot; Root rot; Sclerotinia rot; Septoria leaf spot; Root-knot nematodes; Bacterial leaf spot; Viral diseases (Apium virus Y; Carrot red leaf virus).
Kangkong Leaf beetle; Wireworm; Aphids. Stem rot; Root rot; Leaf spot; Mosaic virus.
Spring onions/Shallots Onion thrips; Cutworms; Cluster caterpillar. Onion white rot; Bacterial spot; Downy mildew; Fusarium basal plate rot; Iris yellow spot virus; Leaf blight; Purple blotch; Rust.
Leeks Onion thrips. Downy mildew; Purple blotch; White rot; Fusarium.
Rocket Cabbage white butterfly; Green caterpillar. Leaf spot; Clubroot.

Pest management:

Use a combination of chemical, cultural, and biological strategies to keep weeds, insect pests, mites, diseases, and other crop production problems low enough to minimise economic crop loss. Monitor the crop regularly using all available monitoring tools and encourage beneficials to control pest problems. The following management strategies are recommended to prevent diseases in bunching vegetables:
  • Wherever possible, avoid watering plants in the evening as this may provide long hours of leaf wetness. Most spores need to germinate and wet leaf surfaces infect plants.
  • A short, heavy watering is preferable to a long, light watering. If possible, overhead irrigation should be avoided.
  • Maintain good air-movement in the environment to lower humidity and thus reduce spore production and infection. This may mean running the rows in the direction of the wind and increasing plant spacing.
  • Maintain a balanced program of nutrition to avoid nutrient disorders.
  • Implement good hygiene practices to avoid moving pests between properties.
  • Rotate bunching crops with non-host crops and do not replant infected sites.
  • Avoid sequential planting as fungi can move from older crops to younger crops.
  • Avoid damage to the plant, as it may provide a point of entry for fungi and bacteria.
  • Combine management practices with a registered fungicide spray program.
  • Implement disease resistance management strategies - Alternate fungicides from different groups of chemicals to avoid fungi developing resistance to fungicides.
  • Removal of weeds within and around the seedlings nursery.
  • Discard any seedlings showing viral symptoms and promptly remove and destroy them.
  • Introduce natural thrips predators regularly and only apply insecticides that are ineffective against these predators.

Source of information and related tools: