Wild radish and its resistance to herbicides is under scrutiny in Victoria’s Wimmera-Mallee cropping region.
A Grains Research and Development Corporation “fast track project”, instigated by the GRDC’s southern Regional Cropping Solutions Networks (RCSN), aims to map the extent of herbicide resistance in wild radish and other broadleaf weeds and increase awareness about the increasing problem.
Birchip Cropping Group (BCG) is undertaking the survey, trial and extension work in response to concerns raised about the spread of resistance in wild radish in the southern cropping region, brought to GRDC’s attention through the RCSN in the low and medium rainfall zones.
The project will also act as a pilot for future surveys in other parts of the southern region.
BCG research agronomist Simon Craig says the project, due for completion in August this year, involves collaboration with various agribusinesses which have assisted in identifying growers’ paddocks where herbicide-resistant wild radish is a concern. Herbicide application trials have been set up in these commercial paddocks.
“These trials will provide the platform for engaging with growers, advisers and industry representatives to increase awareness of developing herbicide resistance in broadleaf weeds,” Mr Craig said.
“The trial sites will be used for crop walks and information days for both growers and advisers, to assist in building awareness and understanding of the increasing threat of resistance.
“This, in turn, will increase the likelihood of rotation of herbicide groups and better management of wild radish where resistance to at least one group is already present.”
Mr Craig said wild radish populations and their level of herbicide resistance was increasing across the Wimmera and Mallee cropping regions where growers have commonly selected herbicides according to their ability to control grasses such as ryegrass or brome grass.
“As a consequence, growers have placed less emphasis on rotating their broadleaf herbicide groups, thereby increasing the potential for resistance to develop in weeds such as wild radish, Indian hedge mustard and turnip.”