With 87 sites across Australia now confirmed with glyphosate resistant ryegrass, the fight against its spread in Western Australia is becoming an imperative.
The Grains Research and Development Corporation (GRDC) has been a leader in the battle against glyphosate resistance, supporting research into practical means of defeating the problem.
Weed consultant, Andrew Storrie, from Agronomo, stresses that while WA’s dry summers work in its favour, with less glyphosate use than in eastern Australia, the potential for increased use, if Roundup Ready canola crops were widely grown, could pose problems.
“However, if growers remain vigilant, do some planning and stay on the ball, glyphosate resistance needn’t be a big issue,” Mr Storrie said.
He stresses that growers need to pay particular attention to firebreaks and fence lines, which can harbour glyphosate resistant weeds.
“Resistance can appear in areas with little competition, like fence lines and firebreaks and can be dragged into the cropped area with harvest and seeding equipment.
“A total vegetation control approach, using herbicides with different modes of action is effective and needn’t be expensive.
“Paraquat, diuron and simazine can control resistant and susceptible annual ryegrass.
“A handful of resistant plants can become a problem if nothing is done about them, so vigilance is important. Small numbers of plants can be hand-pulled and there is no plant resistance to this.”
Mr Storrie says there are currently 8-10 populations of glyphosate resistant ryegrass in WA.
“It’s a problem that could increase if climate change brings increased summer rainfall, so it’s essential that we keep control over the problem, now.”