Herbs

Herbs – an overview:

This page provides an overview of the key pests and diseases of herbs in Australia. The related tools 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. Common herbs in Australia include coriander, basil, dill, mint, lemon grass, and parsley.

Insect pests of herbs include the following:

Caterpillars

Heliothis (Helicoverpa); Cabbage white butterfly; Cabbage cluster caterpillar; Loopers; Cluster caterpillar; Diamondback moth; Cutworms

Aphids

Green peach aphid; Cotton aphid

Silverleaf whitefly

Thrips

Western flower thrips (WFT); Onion thrips

Mites

Broad mite; Red-legged earth mite; Two-spotted mite

Beetles

Flea beetles; Wireworms

Diseases of herbs include the following:

Root rots

Common disease of coriander.

Fusarium wilt

Major disease of basil.

Powdery mildew

A common and widespread disease of dill, coriander, as well as mint.

Bacterial leaf spot

Major problem of coriander crops.

Black spot

A minor disease of basil.

Alternaria leaf blight

A common disease of parsley.

Root-knot nematodes

Feed on the roots of many crops.

Rust

A major disease of mint.

Tangle top

A minor disease that affects lemon grass crops.

Celery mosaic virus

Affects parsley crops.

Pest management

Monitor for pests and beneficials.

Make sanitation on-farm a priority.

Understand all your management options.

Use high quality seeds that offer resistance against diseases.

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. Drip irrigation minimises periods of leaf wetness.

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.

Avoid sequential planting as pests can move from older crops to younger crops.

Destroy crop residues promptly.

Avoid damage to the plant, as it may provide a point of entry for fungi and bacteria.

Combine management practices with a registered insecticide spray program.

Implement insecticide resistance management strategies - Alternate insecticides from different groups of chemicals to avoid pests developing resistance to insecticides.