Control
These nematodes are soil-borne so are usually introduced in contaminated soil on boots, hands, crates, tools and machinery. It is also important to ensure that infested seedlings are not planted, as they will suffer severe damage as well as aiding the introduction or spread of nematodes and re-infecting treated areas.
Once an area is infested, the nematodes can be managed but not eradicated so the best control method is to practise good hygiene.
Pre-planting soil treatment using nematicides is not 100% effective as the protective cysts are tough and can be widely distributed within the soil. Furthermore, these chemicals can be subject to enhanced biodegradation and become less effective when the same chemical is applied repeatedly. Biodegradation is the development of soil organisms that degrade the nematicide.
Nematicides are particularly toxic, so need to be used with care, adhering to withholding periods and according to registered usage for each crop. Information on currently registered chemicals for BCN management can be found at the APVMA website.
Nematode populations can increase rapidly under successive host crops, so an initially low population can increase to high levels by the end of a growing season.
Rotation with a non-host crop such as legumes, corn, cereal, onion or potato can aid in reducing nematode levels. Three to four years may be required and crop rotation is more useful in preventing population build-up than in reducing already high populations.
Weeds can provide a reservoir of infection, contributing to build-up and carry-over of nematodes. Fallow also needs to be weed-free to be effective.
Planting crops when soil temperatures are lower as nematodes are less active and reproduce more slowly can reduce damage. Seedlings are more prone to severe damage than older plants.
AGWEST Plant Laboratories can test soil and/or plant roots for nematodes. To obtain submission forms and full sampling instructions contact +61(0)8 9368 3721 or +61(0)8 9368 3333.
Acknowledgement
The original information for this webpage was authored by Vivien Vanstone.