FARMING systems must incorporate non-herbicide weed contol options in order to maintain available herbicides and reduce the risk of herbicide resistance.
Weed research officer Peter Newman at the Department of Agriculture Geraldton said while herbicide resistance in ryegrass had been documented for the past 15 years, there was cause for alarm with resistance to wild radish, a weed that was well adapted to the Northern Agricultural Region (NAR).
"Like ryegrass, wild radish has developed resistance to Group B herbicides, but Group C and Group I resistance in radish in recent years has set alarm bells ringing," he said.
"Brodal is the backbone of radish control in lupins and 2,4-D for radish control in wheat.
"Without these herbicides it is difficult to imagine that we can continuously crop in the future, with a reliance on herbicides."
Mr Newman proposed a number of strategies to manage herbicide resistance:
pinclude a non-cropping phase in the rotation (hay or pasture);
preduce weed seed bank with seed collection and destruction;
pgrow a competitive crop;
protate the use of herbicides.