Western Australia
February 9, 2012
A management program which incorporates non-chemical strategies to control glyphosate resistant ryegrass is vital for growers working to preserve valuable herbicide options.
While herbicide resistant annual ryegrass is common throughout the wheatbelt, herbicides such as glyphosate or paraquat/diquat remain effective against the vast majority of populations.
The outcomes of a joint Department of Agriculture and Food and Grains Research and Development Corporation (GRDC) glyphosate resistant ryegrass project will be discussed at the Agribusiness Crop Updates on February 28 and 29.
Department research officer Catherine Borger said the research project looked at ways of reducing the spread of glyphosate resistant ryegrass, as well as determining effective strategies that allowed growers to preserve these effective herbicides for another five to ten years.
“Glyphosate and paraquat/diquat are valuable as there are few other chemical options for non-selective weed control,” Dr Borger said.
“Having good management strategies in place now will give our growers the option to use these herbicides for potentially another 10 years and possibly even longer.
“Working with a central wheatbelt grower, we helped in develop a management plans, to prevent glyphosate resistant ryegrass from spreading within the farm or to neighbouring properties.
“Management strategies were in line with the growers desire to minimise herbicide use, be cost effective, maintain normal enterprise practice and not reduce productivity.
“As ryegrass needed to be preserved as pasture for livestock, the best strategy was to maintain a high level of susceptible ryegrass.”
A very dense population of susceptible annual ryegrass plants neighbouring the resistant population reduces the amount of resistant pollen. This in turn reduces the possibility of any susceptible plant being fertilised by a resistant plant and producing resistant seeds,” Dr Borger said.
“As there were usually no herbicides used in the pasture fields, there was low selection pressure on the susceptible population. This allowed susceptibility to be maintained.
“The strategy of maintaining a high density of susceptible annual ryegrass was successful in limiting the spread of glyphosate resistant plants on this property.”
To learn more about the management strategies implemented and how to reduce the spread of glyphosate resistant ryegrass register for the 2012 Agribusiness Crop Updates by visiting www.agric.wa.gov.au/2012cropupdates
The Department for Agriculture and Food’s 2012 Agribusiness Crop Updates, supported by the GRDC, is on 28 and 29 February at the Pan Pacific Hotel in Perth.
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