Pathogenic nematodes of cereal crops in south-west Victoria, Australia

Abstract

A survey of 76 wheat and 12 barley crops was conducted during 1999 and 2000 to determine the importance of root lesion (Pratylenchus spp.) and cereal cyst (Heterodera spp.) nematodes as potential risks to cereal crops in south-west Victoria, Australia, a rapidly expanding high rainfall cropping region. During the growing season, crops were sampled and inspected for symptoms of infestation by cereal cyst nematode. Root lesion nematodes were extracted from roots and quantified. The results showed that cereal cyst nematode was of minor importance to cereal crops in this region. Even though root lesion nematodes were either absent or present at low levels within the roots of most wheat and barley crops, they were present at potentially damaging levels in 16% of crops, and the data showed higher nematode densities following two consecutive crops than following 2 years of pasture. This suggests that with the increased intensification of cropping within the region, root lesion nematodes may become increasingly important and further studies are required to establish their importance. The root lesion nematodes Pratylenchus neglectus, P. thornei, P. crenatus and P. penetrans were all detected during this survey.