Research by the Department of Agriculture, Western Australia on new bread wheats has identified eight varieties with good herbicide tolerance.

Department research officer Harmohinder Dhammu (photo) presented the findings at the Agribusiness Crop Updates this week, which are supported by the Department and the Grains Research and Development Corporation (GRDC).

“We examined 10 wheat varieties sown in June at Merredin and Mullewa, including two new varieties which are yet to be released by the Department,” Dr Dhammu said.

Registered varieties that demonstrated good tolerance to all the herbicides and herbicide mixtures tested include Department varieties Wyalkatchem and EGA Blanco, Bonnie Rock, and Castlerock and Grain Biotech Australia’s varieties GBA Ruby and GBA Sapphire.

“None of the herbicides/ herbicide mixtures evaluated had any significant negative affect on grain yield.

“GBA Shenton demonstrated some sensitivity to the herbicide Dicamba if applied above the registered rate.”

A limited evaluation of EGA Eagle Rock on plots at Mullewa showed sensitivities to Hussar and phenoxy herbicides, but Dr Dhammu said due to the sample restrictions, the result should be taken with caution.

Most of the herbicides were tested at the high label rates, but some of the herbicides were tested above the label rates to further test herbicide tolerance levels of the new varieties to help change the label for better weed control.

Full details of the study will be available following the conference on the Department’s website.