August 15, 2003

Damaging densities of root lesion nematode occur in at least 40 per cent of Western Australia cropping paddocks, and can cause yield losses of up to 10 per cent in wheat and barley crops.

Western Australia Department of Agriculture senior plant nematologist Vivien Vanstone said research was focused on refining management recommendations to help growers control root lesion nematode, particularly through crop rotations.

Dr Vanstone said rotations including lupin, pea or moderately resistant wheat varieties like Wyalkatchem would assist in lowering the soil nematode levels, and decrease crop damage and yield loss.

A demonstration by the department at the Dowerin Field Days will highlight the symptoms caused by root lesion and cereal cyst nematodes, and show how they are different to the fungal diseases like Rhizoctonia root rot and take-all.

Growers will also have the opportunity to observe live nematodes under the microscope and discuss the available diagnostic services. Dr Vanstone said it was important for growers to determine whether nematodes were present or likely to pose a threat to crops.  

“Unlike leaf diseases, nematode infections are harder to diagnose and it is necessary to ‘dig deeper’ to investigate symptoms on the roots.  Nematodes are microscopic, so diagnostic services are often needed,” she said.

“The Department of Agriculture, with the assistance of researchers in South Australia and Canberra, is currently investigating the different types of root lesion nematodes that occur in Western Australia and how to identify them.  The work is funded by the Grains Research and Development Corporation.”

Dr Vanstone said the Department’s statewide crop variety testing trials were being used to gather more information on the resistance or susceptibility to root lesion nematode for a wide range of varieties for all field crops.

She said the research would determine which crops were favoured by the different types of nematodes.

“A ’captive breeding program’ for different types of root lesion nematode is enabling the department’s researchers to study them more closely, and in the future develop capacity to screen cereals for resistance in conjunction with the breeding programs,” she said.