Western Australia
April 22, 2014
Grain growers have been urged to take evasive action now to protect their crop from potentially devastating plant root diseases that could rob them of returns during the growing season.
Soil samples from DAFWA’s 180 Farm Focus Paddocks taken in 2013 have shown a general increase in soilborne diseases, compared with 2010.
2013 was a prolific year for many crop diseases and pests, including crown rot, rhizoctonia and root lesion nematodes, encouraged by a wet autumn.
While this summer has been more dry, crop diseases will still carry over, especially if the ‘green bridge’ – summer weeds and crop volunteers – are allowed to survive through to seeding.
Department of Agriculture and Food senior research officer Bill MacLeod warned growers not to be complacent and to implement preventative measures now, as there are few options once their crops start growing.
“The dry summer conditions will not necessarily reduce the presence of disease, rather it limits the breakdown of the pathogens,” Mr MacLeod said.
“There are no growing season treatments for the diseases crown rot, rhizoctonia and root lesion nematodes, so it is important for growers to have a soil test done before the break of the season to determine if they have a problem and assess what they can do to limit its impact.”
Crop root diseases cost WA grain growers an estimated A$105 million per year in yield and quality losses.
Mr MacLeod said that by knowing their disease risk status growers could make informed decisions to protect their crop and optimise their profitability.
“If growers have a high risk of crown rot they may choose to grow a break crop, such as lupins, chickpeas, clover or canola. However, if growers have a moderate risk they could decide to grow a cereal that’s less susceptible to this disease, such as Emu Rock wheat, or sow between the 2013 stubble rows,” he said.
“Growers will also need to be aware of their risk from root lesion nematodes, as canola is susceptible to this disease.
“When rhizoctonia is a high risk, canola or a chemical fallow may reduce the risk level for the following season.”
The department has a suite of information about crop disease management and its AgWest Plant Laboratories on its website agric.wa.gov.au
Samples can be submitted to AgWest Plant Laboratories during the cropping season and summer for analysis of root disease risks.
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