CUTTING herbicide rates to 80pc of full label rates causes no increase in herbicide resistance levels, according to the results of trials by the Agriculture Department and affiliates.
Department researcher Art Diggle discussed the herbicide trial findings at Crop Updates last week.
Mr Diggle and his associates from the CRC for Australian Weed Management and WA Herbicide Resistance Initiative tested the theory that cutting herbicide rates is more likely to produce herbicide resistance.
The research found cutting the rates to 80pc of the full label rate did not appear to make a difference in major gene resistance.
Mr Diggle said in some instances it caused a more rapid build-up of minor gene resistance.
"It is not known what levels of minor herbicide resistance genes might commonly exist in weed populations in the field," Mr Diggle said.
"However, for a set of theoretical simulated conditions, cutting herbicide rates to 80pc of label rates had no effect on build-up of resistance or else reduced the rate of build-up of resistance in field conditions."
Rates cut to less than 80pc of the label rate were not tested.
Mr Diggle said he did not encourage cutting herbicide rates and that it was safer to use full label rates.