Cyst nematodes of grains and vegetables


​​​ Patchy growth in cereal rye caused by one of the species of cyst nematodes.


Cyst nematodes of grains and vegetables (exotic species)

Exotic to Australia

Features: Exotic species of nematodes (microscopic worm like animals) that damage grains and vegetables
Where they're from: Europe, Asia, Africa, North America, Central America, South America
How they spread: Importation of infested plants or soil, contaminated machinery and footwear
At risk: Grains (oats, wheat, barley, soybeans, rye, maize, sorghum), pulses (chickpea, lentil, broad bean) grasses and vegetables (carrots, beans, peas, beetroot)

Patchy growth in cereal rye caused by one of the species of cyst nematodes.
Bonsak Hammeraas, Norwegian Institute for Agricultural and Environmental Research,

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Keep them out

Overseas, these cyst nematodes(Heterodera spp.) attack a wide range of pulses, grains, and vegetables including carrots, beans and peas.  They infest and attack the roots causing wilting and stunting of plants. They can spread easily via infected plants or soil.

These pests cause huge economic losses for farmers where they live in the soil. One species, H. zeae (corn cyst nematode), is spreading through grain growing areas of the US, ruining crops.  Another species, H. glycines (soybean cyst nematode), damages soybeans, causing up to 70 per cent loss of yield in crops in Japan.

These cyst nematodes pose a significant threat to our agricultural industry and our economy, since vegetables and grains are important crops. Soil infested with cyst nematodes may not be suitable for growing these crops. They might also threaten grasses in Australia.

Importing goods

To keep these exotic cyst nematodes out of Australia, never ignore Australia’s strict biosecurity rules.

Before you import, check our Biosecurity Import Conditions system (BICON).

What to look for

In cereals and vegetables:

  • yellowing, stunting of plants, poor tillering (production of side shoots), and patchy growth
  • thin leaves with a reddish yellow colouring
  • damaged roots, often with a knotted appearance due to cysts, or are ropey and swollen
  • tiny white cysts on roots, which turn brown as the season progresses.
Soybean cyst nematode (H. glycines) on soybean roots including cysts. Jonathan D. Eisenback, Virginia Polytechnic Institute and State University,
Soybean cyst nematode (H. glycines) on soybean roots including cysts.


Where to look


Infested plants are the most likely ways that cyst nematodes could make it to Australia. They could also enter on machinery and footwear contaminated with infested soil. 

Growers and home gardeners

Look for signs of exotic cyst nematodes in:

  • grain crops and grasses
  • vegetables including carrot.

What to do

If you think you’ve found exotic cyst nematodes in crops of grains, vegetables or grasses:

  • take a photo
  • do not disturb infected plants (this may be as simple as preventing access to a field).

Seen something unusual? Report it. Even if you’re not sure.

Read the detail


Last reviewed: 17 December 2020
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