Western Australia
October 5, 2015
![People at a field walk.](https://www.agric.wa.gov.au/sites/gateway/files/styles/portrait_medium/public/RLN%20research%20field%20walk.JPG?itok=Vc5k4cvz)
DAFWA research officer Dr Sarah Collins took a group of scientists on a field walk to look at a RLN trial near Moora recently. Research suggests a link between RLN and acidic soils.
Western Australia’s acidic soils could be exacerbating the impact of root lesion nematodes (RLN) and limiting crop yields and growers’ profitability.
Initial research by the Department of Agriculture and Food, supported by the Grains Research and Development Corporation (GRDC), has found significantly higher RLN populations in barley, lupin and wheat crops grown in low pH soils.
RLN, microscopic pests that feed on plant roots, are found across more than 5.3 million hectares of WA cropping paddocks, while soil acidity impacts more than 14m hectares of the Wheatbelt.
The department’s research was profiled at the recent Australasian Plant Pathology Society conference in Fremantle by department research officer Sarah Collins.
Dr Collins’ nematology research group conducted a series of glasshouse trials to test the impact of soil acidity on the multiplication of the main RLN species that impact WA wheat, barley and lupin crops.
The plants were grown in acidic soils (pH 5.1) taken from the same paddock and compared with plants grown in soil that had been treated with lime (pH 6.7).
“Significantly higher final populations of P. quasitereoides were recorded for seven of the nine wheat, barley and lupin varieties grown in low pH soil compared with the same varieties grown in the same soil limed to moderate pH,” Dr Collins said.
“The same result was recorded in barley for P. neglectus.
“The interaction between soil acidity and wheat variety resistance to P. neglectus was not conclusive in this trial but in an earlier experiment using more acid soils (pH 4.7) compared with moderate soils (pH 6.4), the final P. neglectus populations were significantly higher in five out of six wheat varieties grown in the low pH soils.”
Dr Collins said that while the research suggested that moderate to highly acidic soils were exacerbated plant susceptibility to RLN, more research was required.
“Our research indicates that wheat, barley and lupins could be at greater risk of damage from root lesion nematodes in acidic soils,” she said.
“It also means that the more resistant cereal varieties listed in WA’s barley and wheat variety guides may have less reliable performance to RLN in acidic soils.”
The relationship between RLN and soil acidity is being investigated as part of national collaborative research on nematode management, established in conjunction with the GRDC.
Acidic soils are a major constraint to WA grain growers, costing the industry about $500 million per annum.
The department has undertaken extensive research on lime incorporation to address constraints due to acidic soils, as well as years of research on RLN.
Further diagnostic and management information is available by downloading the free MyCrop apps for wheat, barley, canola and lupins.