Springtails (Bourletiella spp.)

Attack cotyledons and emerging plants, smooth edge damage, damaging until the 4th leaf stage

Ultrastrike® or Superstrike® seed treatment, chemical, crop rotation and hygiene

Greasy cutworm (Agrotis ipsilon aneituma)

Plants, especially seedlings ripped off at or just below ground level, young plants wilt

Chemical, crop rotation and hygiene

Grass grub (Costelytra zealandica)

Adults attack young growing points, larvae attack seedling roots

Chemical

Wheat bug (Nysius huttoni)

Ring barking of seedlings at ground level leaves plants susceptible to other attacks, damage is similar to that caused by wirestem

Ultrastrike + chemical

Weevils (Catopes spp.)

Chew cotyledons or stem at ground level, scalloping of leaf edge

Chemical

Slugs (many species)

Creates severe damage to brassica plants by destroying seedlings

Minimise crop residual or trash before directdrilling, use slug baits, cultivate paddocks

Wirestem/strangles (Rhizoctonia solani)

Brown lesions at ground level, narrowing of root and stem base, often caused by strangles, damage similar to that caused by wheat bug. Wirestem/ Strangles - damage to sap flow from abrasion at ground level by wind etc. Affected tissue susceptible to fungal attack (wirestem)

Ultrastrike® or Superstrike® seed treatment, chemical

Damping off (Fusarium and Pythium)

Affects seedlings in the first few weeks after sowing. Infected seedlings either fail to emerge or recently emerged plants can collapse, with plants revealing shrivelling and discolouration at the shoot base

Ultrastrike® or Superstrike® seed treatment

Aphids (many species)

Sap suckers that weaken plants, reduce yields, carry viral diseases, mainly attack summer crops

Tolerant cultivars to certain aphid species, Ultrastrike® seed treatment, chemical

Diamondback moth (Plutella xylostella)

Young larvae burrow in and feed on internal leaf tissue, older larvae feed on lower leaf surfaces, larvae damage is often holes, some quite large, similar to white butterfly caterpillar

Chemical

White butterfly (Pieris rapae)

Leaf feeding leaves skeletonised leaf with leaf ribs remaining

Chemical

Leaf miners (many species)

Larvae create tunnels and live within leaf tissue, tissue damage may reduce photosynthetic activity and cause leaf yellowing, premature leaf death and limit growth at this time. Damage is similar to that caused by Diamondback moth

Chemical

Turnip mosaic

Stunted growth, mottling and crinkled leaves, yellowing, leaf death, poor bulb development

Control of vector aphids

Beet western yellows

General stunted growth, purpling of leaves

Control of vector aphids

Cauliflower mosaic

Poor vigour, can attack all brassica species

Control of vector aphids

Clubroot (Plasmodiophora spp.)

Causes irregular swelling of root, leaf wilting, stunted growth and plant death

Crop rotation (6 years in high risk areas), hygiene, reduce double cropping

Dry rot (Leptosphaeria maculans)

Affects swedes mainly, small sunken brown-grey circular spots on leaf or bulb neck, plant death

Crop rotation and hygiene, more tolerant cultivars, reduce double cropping

Ring spot (Mycosphaerella brassicicola)

Small dark spots on older leaves in cool wet conditions

Crop rotation

Leaf spot (Alternaria spp.)

Small dark lesions and dark sooty mould on leaves, may lower yields

Chemical

Black rot (Xanthomonas campestris)

Attack on vascular system in warm humid conditions, yellowing of leaf margins, wilting, leaf loss

Crop rotation

Rust

Orange spores cover leaf surfaces. Effect on yield is yet to be confirmed

Research ongoing

Powdery Mildew

White powdery substance on leaf surface. Evidence suggests a yield reduction may occur

Research ongoing

Brown heart

Boron deficiency, affects bulb crops

Soil testing, boron fertiliser application