5 May 1995

…with natural

control and genetic change

MORE radical methods of controlling nematodes were also aired at the conference.

Brian Kerry of IACR-Rothamsted explains that some bacteria are thought to affect root secretions, making them less attractive to nematodes. Toxin production and induced resistance may also play a part.

Certain Verticillium fungi which colonise root surfaces also switch to nematode parasitism. Identifying the most virulent types and understanding why they attack nematode eggs will help scientists select candidates.

A strategy to use this fungus to control root-knot nematodes in vegetable crops has been devised and is being tried.

Nematodes could also soon be controlled by genetically-modified plants, says Lieve Gheysen of the University of Ghent in Belgium.

Either nematode toxins derived from naturally-occurring fungi or bacteria could be used. &#42