First record of damage to canola caused by the oat race of stem nematode (Ditylenchus dipsaci)

The oat race (o.r.) of stem nematode Ditylenchus dipsaci, which occurs in the mid-north area and on Yorke Peninsula in South Australia, mainly affects susceptible varieties of oats and faba beans. In July 1998, patches and poor emergence were observed in four paddocks of canola seedlings. Plant symptoms included distorted leaves and stems. Stem nematode was recovered from affected plants. Symptoms were reproduced in ten cultivars of canola seedlings by inoculation with stem nematode (o.r.). Adult canola plants showed both tolerance and resistance in the field and in pot trials.